PiHow

pihow

Hey Hackers, PIHOW Services has been nominated in HackerNoon's annual Startups of The Year awards in Jajpur, India. Please vote for us here: https://hackernoon.com/startups/industry/design Read more about us below to understand why we deserve your vote. Meet PIHOW At PIHOW Services, we specialize in delivering tailored web development and design solutions that empower businesses to achieve a seamless digital presence. Whether you're a startup looking for a website or an established brand in need of a design overhaul, we provide cutting-edge, user-centric solutions that blend creativity with functionality. How PIHOW achieved product-market fit PIHOW Services thrives because of its unique blend of technical expertise and design innovation, serving clients from various industries. We've received consistent positive feedback from clients who appreciate our personalized approach, fast turnarounds, and ability to stay ahead of design trends. We've grown through word-of-mouth recommendations, reflecting our strong fit in the freelance web development and design market. The evolution of PIHOW PIHOW Services started as a freelance gig but quickly grew as we recognized the increasing demand for high-quality, custom-built websites and creative designs. Along the way, we’ve continuously refined our processes to prioritize user experience and functionality, which has become the core of our service offerings. Initially, we focused solely on small-scale website design, but after seeing a rising demand for integrated solutions that combined web development with branding, we pivoted towards offering full-service digital solutions. This shift allowed us to target larger businesses and create more impactful designs. User feedback has been crucial. Our clients wanted more than just aesthetically pleasing designs—they needed platforms that perform. By listening, we’ve emphasized creating responsive, SEO-friendly websites that enhance the user journey, not just the visuals. Milestones and achievements Delivered over 90 custom web solutions to businesses across various industries.
Expanded from a one-person operation to a full team of designers and developers.
Garnered positive client reviews, resulting in a 90% client retention rate.
Secured partnerships with key industry players in e-commerce and education. Lessons learned One of our biggest challenges has been managing scaling demands while maintaining a high standard of quality. We learned that growing too fast can strain resources, so we’ve focused on strategic growth and building a reliable, scalable infrastructure. What Startups of The Year means to us Being recognized in HackerNoon's Startups of The Year is an exciting opportunity to showcase our work and connect with a wider community of innovators. It validates our efforts and helps us reach new clients who are looking for dependable freelance web development services. Conclusion At PIHOW Services, we’re passionate about delivering designs that not only look great but also serve as powerful tools for growth. We’re excited to continue pushing boundaries and setting new standards for web development. Vote for us today! https://hackernoon.com/startups/industry/design. Hey Hackers, Hey Hackers, PIHOW Services has been nominated in HackerNoon's annual Startups of The Year awards in Jajpur, India . PIHOW Services Jajpur, India Please vote for us here: https://hackernoon.com/startups/industry/design Please vote for us here: https://hackernoon.com/startups/industry/design Please vote for us here: https://hackernoon.com/startups/industry/design https://hackernoon.com/startups/industry/design Read more about us below to understand why we deserve your vote. Read more about us below to understand why we deserve your vote. Meet PIHOW At PIHOW Services, we specialize in delivering tailored web development and design solutions that empower businesses to achieve a seamless digital presence. Whether you're a startup looking for a website or an established brand in need of a design overhaul, we provide cutting-edge, user-centric solutions that blend creativity with functionality. How PIHOW achieved product-market fit PIHOW Services thrives because of its unique blend of technical expertise and design innovation, serving clients from various industries. We've received consistent positive feedback from clients who appreciate our personalized approach, fast turnarounds, and ability to stay ahead of design trends. We've grown through word-of-mouth recommendations, reflecting our strong fit in the freelance web development and design market. The evolution of PIHOW PIHOW Services started as a freelance gig but quickly grew as we recognized the increasing demand for high-quality, custom-built websites and creative designs. Along the way, we’ve continuously refined our processes to prioritize user experience and functionality, which has become the core of our service offerings. Initially, we focused solely on small-scale website design, but after seeing a rising demand for integrated solutions that combined web development with branding, we pivoted towards offering full-service digital solutions. This shift allowed us to target larger businesses and create more impactful designs. User feedback has been crucial. Our clients wanted more than just aesthetically pleasing designs—they needed platforms that perform. By listening, we’ve emphasized creating responsive, SEO-friendly websites that enhance the user journey, not just the visuals. Milestones and achievements Delivered over 90 custom web solutions to businesses across various industries. Expanded from a one-person operation to a full team of designers and developers. Garnered positive client reviews, resulting in a 90% client retention rate. Secured partnerships with key industry players in e-commerce and education. Delivered over 90 custom web solutions to businesses across various industries. Expanded from a one-person operation to a full team of designers and developers. Garnered positive client reviews, resulting in a 90% client retention rate. Secured partnerships with key industry players in e-commerce and education. Lessons learned One of our biggest challenges has been managing scaling demands while maintaining a high standard of quality. We learned that growing too fast can strain resources, so we’ve focused on strategic growth and building a reliable, scalable infrastructure. What Startups of The Year means to us Being recognized in HackerNoon's Startups of The Year is an exciting opportunity to showcase our work and connect with a wider community of innovators. It validates our efforts and helps us reach new clients who are looking for dependable freelance web development services. Conclusion At PIHOW Services, we’re passionate about delivering designs that not only look great but also serve as powerful tools for growth. We’re excited to continue pushing boundaries and setting new standards for web development. Vote for us today! https://hackernoon.com/startups/industry/design. Vote for us today! https://hackernoon.com/startups/industry/design. Vote for us today! https://hackernoon.com/startups/industry/design . https://hackernoon.com/startups/industry/design

Leading the Charge in Digital Transformation: Interview with SOTY 2024 Nominee, PIHOW 

Metaphysics and Mathematics 2: The Complex Space of Prime Numbers

Recently, I mentioned to keep up-to-date. Since Geecon Prague, I'm also a happy owner of a Raspberry Pi: how I refactored the script my GitHub profile Though the current setup works flawlessly - and is free, I wanted to experiment with self-hosted runners. Here are my findings. Context GitHub offers a large free usage of GitHub Actions: GitHub Actions usage is free for standard GitHub-hosted runners in public repositories, and for self-hosted runners. For private repositories, each GitHub account receives a certain amount of free minutes and storage for use with GitHub-hosted runners, depending on the account's plan. Any usage beyond the included amounts is controlled by spending limits. -- About billing for GitHub Actions Yet, the policy can easily change tomorrow. Free tier policies show a regular trend of shrinking down when: A large enough share of users use the product, lock-in Shareholders want more revenue A new finance manager decides to cut costs The global economy shrinks down A combination of the above Forewarned is forearmed. I like to try options before I need to choose one. Case in point: what if I need to migrate? The theory GitHub Actions comprise two components: The GitHub Actions infrastructure itself. It hosts the scheduler of jobs. Runners, who run the jobs By default, jobs run on GitHub's runners. However, it's possible to configure one's job to run on other runners, whether on-premise or in the Cloud; these are called . self-hosted runners The regarding how to create self-hosted runners gives all the necessary information to build one, so I won't paraphrase it. documentation I noticed two non-trivial issues, though. First, if you have jobs in different repositories, you to set up a job for each repository. Runner groups are only available for organization repositories. Since most of my repos depend on my regular account, I can't use groups. Hence, you must duplicate each repository's package on the runner's Pi. need In addition, there's no dedicated package: you must untar an archive. This means there's no way to upgrade the runner version easily. That being said, I expected the migration to be one line long: jobs:
  update:
    #runs-on: ubuntu-latest
    runs-on: self-hosted It's a bit more involved, though. Let's detail what steps I had to undertake in my repo to make the job work. The practice GitHub Actions depend on Docker being installed on the runner. Because of this, I thought jobs ran in a dedicated image: it's plain wrong. Whatever you script in your job happens on the running system. Case in point, the initial script installed Python and Poetry. jobs:
  update:
    runs-on: ubuntu-latest
    steps:
      - name: Set up Python 3.x
        uses: actions/setup-python@v5
        with:
          python-version: 3.12
      - name: Set up Poetry
        uses: abatilo/actions-poetry@v2
        with:
          poetry-version: 1.7.1 In the context of a temporary container created during each run, it makes sense; in the context of a stable, long-running system, it doesn't. Raspbian, the Raspberry default operating system, already has Python 3.11 installed. Hence, I had to downgrade the version configured in Poetry. It's no big deal because I don't use any specific Python 3.12 feature. [tool.poetry.dependencies]
python = "^3.11" Raspbian forbids the installation of any Python dependency in the primary environment, which is a very sane default. To install Poetry, I used the regular APT package manager: sudo apt-get install python-poetry The next was to handle secrets. On GitHub, you set the secrets on the GUI and reference them in your scripts via environment variables: jobs:
  update:
    runs-on: ubuntu-latest
    steps:
      - name: Update README
        run: poetry run python src/main.py --live
        env:
          BLOG_REPO_TOKEN: ${{ secrets.BLOG_REPO_TOKEN }}
          YOUTUBE_API_KEY: ${{ secrets.YOUTUBE_API_KEY }} It allows segregating individual steps so that a step has access to only the environmental variables it needs. For self-hosted runners, you set environment variables in an existing file inside the folder. .env jobs:
  update:
    runs-on: ubuntu-latest
    steps:
      - name: Update README
        run: poetry run python src/main.py --live If you want more secure setups, you're on your own. Finally, the architecture is a pull-based model. The runner constantly checks if a job is scheduled. To make the runner a service, we need to use out-of-the-box scripts inside the runner folder: sudo ./svc.sh install
sudo ./svc.sh start The script uses underneath. systemd Conclusion Migrating from a GitHub runner to a self-hosted runner is not a big deal but requires changing some bits and pieces. Most importantly, you need to understand the script runs on the machine. This means you need to automate the provisioning of a new machine in the case of crashes. I'm considering the benefits of running the runner inside a container on the Pi to roll back to my previous steps. I'd be happy to hear if you found and used such a solution. In any case, I'm not migrating any more jobs to self-hosted for now. To go further: About billing for GitHub Actions About self-hosted runners Configuring the self-hosted runner application as a service Originally published at on March 10th 2024 A Java Geek

Using Raspberry Pi to Migrate GitHub Runners to Self-Hosted Ones

Would you leave a Google Staff Research Engineer role just because you want your TV to automatically pause when you get up to get a cup of tea? Actually, how is that even relevant, you might ask. Let’s see what Pete Warden, former Google Staff Research Engineer and now CEO and Founder of Useful Sensors, has to say about that. From Jetpac to Google and TinyML, from Google to AI in a Box Pete Warden wrote the world’s only mustache detection image processing algorithm. He also was the founder and CTO of startup Jetpac. He raised a Series A from Khosla Ventures, built a technical team, and created a unique data product that analyzed the pixel data of over 140 million photos from Instagram and turned them into in-depth guides for more than 5,000 cities around the world. Jetpac was acquired by Google in 2014, and Warden has been a Google Staff Research Engineer from then till March 2022. That’s when he founded , which he sees as the evolution of the work he’s been doing at Google. Warden was the Technical Lead of the TensorFlow Mobile team, responsible for deep learning on mobile and embedded devices. Useful Sensors . Naturally, much of what he did was based on things others were already working on: “A lot of my contribution has been helping publicize and document a bunch of these engineering practices that have emerged,” Warden said. Either way, is getting big, and Warden is a big part of it. Warden is sometimes credited as having kickstarted the TinyML subdomain of machine learning TinyML Tiny machine learning (TinyML) is broadly defined as a fast-growing field of machine learning technologies and applications, including hardware, algorithms, and software capable of performing on-device sensor data analytics at extremely low power, typically in the mW range and below, and hence enabling a variety of always-on use-cases and targeting battery operated devices. Useful Sensors just launched a product called , which it dubs an “offline, private, open source LLM for conversations and more.” Even though it’s not the first product Useful Sensors has created, it’s the first one that’s officially launched. That was a good opportunity to catch up with Warden and talk about what Useful Sensors is working on. AI in a Box Click to listen to the full conversation on the . here Orchestrate all the Things podcast Simplicity and the creepiness factor While it is true that Warden cited wanting his TV to automatically pause when he gets up to get a cup of tea as part of the reason why he started Useful Sensors, some context is definitely needed. Part of Warden’s motivation for his work on Tensorflow for embedded devices was to see it used in everyday objects. As Warden related, when he went to talk to companies that made light switches or TVs to tell them “all about this wonderful open source code that they could get for free, and all the conferences and documentation and examples and books,” they would hear him out. But then, in the end, they’d usually say something like: “That’s great. But we barely have a software engineering team, let alone a machine learning team. So can you just give us something that gives us a voice interface or tells us when somebody sits down in front of the TV”? That’s quite telling, and producing self-contained hardware is a valid reason to set out on a new venture. However, that’s not something Google itself could not achieve. Google Pixel, for example, already provides automatic captions running on-device for content that plays on the phone. But there’s something more: privacy and data sovereignty, aka “the creepiness factor”. AI-enhanced In a video hosted on the Useful Sensors home page, Warden mentions how, during his tenure at Google, he would often get questions about whether Google was spying on people. Those questions are valid ones, triggered by a widely observed phenomenon: when mentioning the topic XYZ in the vicinity of your phone, you will often get bombarded with ads about XYZ for days on end. Warden, on his part, swears that the code he was working on does not do that. But, he goes on to add, he has no way of proving that because the code is proprietary. Plus, we may add, there’s nothing anyone can say about other parts of Google’s codebase, or other apps for that matter. It’s hard to light-heartedly dismiss such a widely shared experience. Useful Sensors That brings us to the core of it all – what Useful Sensors does and how it’s different. The vision, as Warden put it, is to be able to run machine learning locally and to do it in a private and checkable way. Everything should run locally with no internet connection, so conversations and data are completely secure. No account, setup, or subscription needed. Warden shared that Useful Sensors has already launched the person sensor, a small board that provides and indication of whether there’s a person nearby, as well as a tiny QR code. Both run entirely locally and retail at $10 and $7, respectively, Warden said. But these products have something else in common too: they are aimed at makers, i.e., hobbyists with enough motivation and technical skills to tinker with them, but also at electronics vendors. As Warden shared, Useful Sensors is currently in talks with a number of electronics vendors. Useful Sensors products are being evaluated, and Warden is hopeful that it won’t be too long before they end up being included in devices sold in the market. In fact, that is the audience that holds the greatest promise for Useful Sensors. Its backers also see the potential, apparently, as the company has received $5 million in seed funding already. Warden co-founded Useful Sensors with CTO Manjunath Kudlur, formerly of Cerebras. Kudlur was the compiler team lead at Cerebras as well as one of the founders of Google’s TensorFlow and Nvidia’s CUDA. Warden said Kudlur contributes greatly to things such as accelerating transformer models for Useful Sensors. The team lists a total of 8 people at this point, but if their plans come to fruition, another funding round and growth are well within sight, as per Warden. AI in a Box, the product that Useful Sensors just launched, seems like it was designed to do a number of things. First, it can grow awareness for Useful Sensors, as it’s aimed at makers. As Warden said, people can tinker with the code, but it already does some useful things out of the box. It can provide live captions, as well as receive voice commands and translate between multiple major languages on the fly. AI in a Box can also help raise some cash for Useful Sensors. But perhaps more importantly, it positions Useful Sensors as an ecosystem provider. This seems like part of the vision for the company, and Warden shared that he’s hoping people will get creative with AI in the Box. In fact, he added, some examples of things people have built with Useful Sensors products already exist on . Hackster Under the hood AI in a Box features a RockChip 3588S SoC with an . The NPU is a unit specifically designed to accelerate neural networks, and the team was able to leverage it to enable a Large Language Model to run locally. AI in a Box is built on a foundation of open-source models like and . In the same vein, the company is releasing all the code to accelerate and control the system under an open-source license. NPU Whisper Llama2 Useful Sensors is also available. The idea is that transparency should help with security and privacy auditing, with Warden noting he’d be happy to have regulators audit Useful Sensors products. Releasing open-source code will also enable developers to use the system as a base to build their own real-time voice input applications in Python. library for optimized transformer inference on the RockChip NPU Warden said that once they were able to get the real-time speech-to-text working, there was lots of choices around which LLMs they could run locally. The team is also looking into doing some of its own fine-tuning, but they’ve been able to get a long way by just providing prompt contexts for interactions. As Warden noted, anybody who’s familiar with LLMs would probably easily recognize what Useful Sensors did. Real-time speech-to-text enables AI in a Box in a box to function as a keyboard too, among other things. By having an LLM in the mix, too, that opens up a range of possibilities. For example, LLMs are known to be able to interface with APIs. Warden mentioned Raspberry Pi as an example that could enable people to control a number of devices using voice commands. AI, innovation, empowerment An example of what people are already working on, Warden said, is an actor who is using the company’s person sensor to automate spotlight operation for solo performances. Rather than having to pay someone to operate a spotlight, the actor is hoping it should be possible to automate this. In a way, that’s a perfect metaphor for the double-edged sword that innovation and AI truly are. That may sound like a good idea for the actor, but what about the operator? “That’s that’s a really big question with anything around innovation. If we’re, quote unquote, making things more efficient, what are the societal impacts of that? A big part of what I’m trying to do is get these technologies into people’s hands so that it’s not just a bunch of engineers who are making these decisions about what we should do. People can try these models for themselves, and see, for example, how useful, but also how flawed the current generation of LLMs are. I don’t want us technocrats to be the ones making these decisions. I want a well informed public who are actually able to say – hey, this is what we want”, Warden said. That certainly sounds like a noble aspiration. How compatible it really is with VC backing, a cut-throat competitive landscape dominated by the Googles of the world, the public’s ability to elaborate its own take on things, and administrations’ willingness to take the public into account remains to be seen. Also published . here

Useful Sensors: Pioneering AI with AI in a Box, A Different Paradigm for Edge Computing

The RP2040 is a microcontroller developed by that has opened up a world of possibilities for DIY electronics enthusiasts. With its built-in USB 2.0 support, the RP2040 can function as a FULL SPEED (12Mbps) device as well as a LOW SPEED (1.5Mbps) and FULL SPEED host. In this blog post, we'll explore custom USB endpoints and how you can use them to create your own custom USB devices. raspberry pi Before diving deep into the topic, let me give you a brief idea what a USB is and how it works. We all know what a USB connector looks like and we use at least one USB device daily. USB stands for Universal Serial Bus. It is a standard interface used to connect various devices to a computer or other host devices. It was developed in the mid-1990s, and it has since become one of the most widely used methods for connecting peripherals to computers. USB allows devices to be connected to a computer without requiring specialized hardware or software. It is a plug-and-play interface, meaning that devices can be connected and disconnected from a computer without needing to restart the computer (Referred to as HOST). The HOST is responsible for all the communication and the device cannot communicate anything on its own. When a device(for ex. Mouse, keyboard, Printer) gets connected to the HOST (Computer) the HOST communicates with the device to know its capabilities through Device Descriptors and configuration descriptors. Once the HOST knows what the device is, it starts communicating with it with the help of device drivers. Types of USB Transfer Control Transfer - It is used to set and get USB configurations, set device address and other settings. All USB Devices must support Control Transfers. Isochronous Transfer - This transfer is used when the data bandwidth required is high and error correction is not important. For Ex- Streaming audio and video Interrupt Transfer - This transfer works by polling. It Polls the device periodically for any data. Keyboard and mouse use this transfer to report key strokes and movements. Bulk Transfer - This transfer provides reliable data transfer but the bandwidth is not guaranteed every time. This is typically used for printers and scanners etc. If you want to get more detail of how everything works I highly recommend you to check out . USB Made Simple What we will be doing In this blog, I will be showing you how I created a composite USB device which can act as a USB keyboard and a custom Endpoint for communication and transferring data. The Device structure is shown below. Here we have 1 configuration and 2 interfaces for the device (RP pico in our case). Interface for a HID device ( uman nterface evice), in our case it will be a Keyboard.
Learn more about HID Devices . H I D here Interface for our custom Bulk Transfer End points, which we will use to transfer data from host to device.(To Control the on Board LED which you will see later). Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0 
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0xcafe 
  idProduct          0x4014 // Vendor ID and Product ID pair is used to identify a device to load suitable drivers.
  bcdDevice            1.00
  iManufacturer           1 Raspberry Pi 
  iProduct                2 RP2040
  iSerial                 3 001
  bNumConfigurations      1 //our device only has one Configuration
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x0039
    bNumInterfaces          2 //2 Interfaces, one for the HID keyboard and other for our custom endpoints
    bConfigurationValue     1
    iConfiguration          4 
    bmAttributes         0xa0
      (Bus Powered)
      Remote Wakeup
    MaxPower              100mA //max current limit for our device USB2.0 supports uto 500mA
    Interface Descriptor:  //This is the Interface for HID keyboard
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         3 Human Interface Device
      bInterfaceSubClass      0 
      bInterfaceProtocol      0 
      iInterface              5 
        HID Device Descriptor:
          bLength                 9
          bDescriptorType        33
          bcdHID               1.11
          bCountryCode            0 Not supported
          bNumDescriptors         1
          bDescriptorType        34 Report
          wDescriptorLength     239
         Report Descriptors: 
           ** UNAVAILABLE **
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0010  1x 16 bytes
        bInterval               5
    Interface Descriptor: //This is the Interface for our custom endpoints (for contolling the LED in this example)
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass      0 
      bInterfaceProtocol      0 
      iInterface              6 
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x03  EP 3 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x83  EP 3 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               0 I have used in ubuntu to see device descriptors. You can also use on windows to do the same. lsusb USBView You can think of interfaces as functions (or a group of functions) which a device performs and endpoints as a dedicated channel or stream of data between host and device. (This is just to give you an idea) USB2.0 Support 16 Endpoints (From 0 to 15) out of which Endpoint 0 is reserved (For device configuration and setup). Each Endpoint can be configured to act as a IN or OUT endpoint. The direction of Endpoints are always from the perspective of the HOST. means Data Transfer from device to HOST means Data Transfer from HOST to device IN OUT In our configuration we have used 1 IN endpoint for Keyboard (To send Keystrokes to the HOST), 1 IN Bulk endpoint to send data from device to HOST and 1 OUT Endpoint to send data from Host to device. You can find the entire project code here . Pyusb-RP-PICO Results 1. Sending character "A" to the HOST Pressing Button on the RaspberryPi Pico Result 2. Sending Data The HOST Program is controlling the on Board LED. For Further Reading you can Refer these: Pyusb-RP-PICO Github Repo USB Made Simple Raspberry Pi Pico USB Compelte 5th Edition pyusb tinyusb Thankyou for reading! 😄 Follow me on https://twitter.com/shekhu_verma

How to Unlock the Power of Custom USB Endpoints w/RaspberryPi PICO and PYUSB

Making My IoT Security Camera System on Render

A Raspberry Pi is a mini-computer board to which you can connect a monitor, mouse, and keyboard, and install a Linux-based operating system with a GUI. Or you can use it in “headless” mode with no GUI and run, for example, a database server. There are you can give a Raspberry Pi—from building a Minecraft server to smart mirrors, the possibilities are endless. many usages Since I started to discover MariaDB and learned about database clusters, , and , the idea of building a Raspberry Pi cluster has been in the back of my head. A cluster like this is a great way to experiment with distributed systems. Distributed SQL Xpand In this article, I’ll show you how to build a Raspberry Pi cluster with: 8 nodes 32 cores 64 GB of RAM 2TB of storage What You Need If you want to build your own cluster, you don’t have to buy 8 Raspberry Pi devices. Even one device is enough to learn stuff. The instructions in this article are useful even if you plan to configure only one My advice, however, is to have at least three devices to build your cluster if you truly want to boost your skills in administration, , , , … you name it! Raspberry Pi. Linux Ansible Docker Kubernetes database clusters With that in mind, please replace 8 with whatever is your number. Do the same with the specifications of the Raspberry Pi devices if you have different models with less or more RAM or storage. Here’s what I used: 8 x (8 GB RAM) Raspberry Pi 4 Model B 1 x (10-Ports) Anker 60W Desktop Charger 8 x (5A, 40W, 23cm) Short USB Type C cable 8 x (256 GB) MicroSD card 2 x (4 layers with cooling fan) Raspberry Pi cluster case Adapt the quantities to your setup. You can either get one or more if you have very few devices (say 1 or 2) or a multi-USB charger. If you go with a multi-USB charger, make sure that each port can deliver at least 2.4Am (5V). Pick microSD cards that fit your goals and budget as well. I recommend going with at least 32 GB SD cards. Raspberry Pi power supplies On the cables and case side, pick anything that accommodates your setup. You don’t necessarily need cooling fans, but I recommend them if you plan to leave your devices on for prolonged periods of time. I also recommend getting all the ingredients before you start “cooking," especially if you want to use multiple Raspberry Pi devices. Installing Raspberry Pi OS (Headless) The operating system (OS) we’ll use is , a Debian-based OS optimized for Raspberry Pi boards. Raspberry Pi OS is installed on the microSD cards using your computer. You later connect these microSD cards to your Raspberry Pi devices and boot them. Raspberry Pi OS Get all the microSD cards and Raspberry Pi boxes on your desk. You’ll need an SD card adapter (they usually come with microSD cards) or an SD card USB reader if your working computer doesn’t have a slot for SD cards. Bring a Sharpie as well. Download the application, and install it on your computer. Take a microSD card and connect it to your computer. Open the Raspberry Pi Imager application, and click on . From the list, click on and select if your Raspberry Pi devices are 64-bit or otherwise: Raspberry Pi Imager CHOOSE OS Raspberry Pi OS (other), Raspberry Pi OS Lite (64-bit) Raspberry Pi OS Lite (32-bit) Click on and select the microSD card. Double-check that you selected the correct drive, and click on the “gear” icon (advanced options). For hostname use , or something similar. You’ll be naming the devices as , , , etc. CHOOSE STORAGE, rpi01 rpi01 rp02 rp03 Check the and options. Set a username (I’ll leave the default ), and set a secure password. Enable SSH, Use password authentication pi Check the option, and enter the name and password of your WiFi connection. Configure your locale settings as well. Configure wireless LAN Since we have to do this once with each microSD card, make sure to set the options field to: . This way the settings will be saved, and the process will be easier for the next cards: Image customization to always use Now, you can click and then to start the process. Once completed, eject the card and connect it to one of the Raspberry Pi devices, put it back into its box, and mark the box with the number . Repeat this process for all of the devices. SAVE WRITE 01 Assembling the Cluster Depending on what kind of cluster case you have, the assembling process might vary. Follow the instructions that come with your case, or look for photographs online to get a clear idea of how the devices should be placed in the layers. I recommend looking ahead to decide which parts to assemble first. For example, with the case I picked, I had to install the cooling fans before mounting the Raspberry Pi devices on the layers. Once you mount a Raspberry Pi, use a Sharpie to write its number on the layer. This will help you in the future if you have to take a microSD card out for reconfiguration or any other administrative tasks that involve touching the hardware. Once you have all the devices mounted, connect the USB cables to the Raspberry Pi devices and the multi-USB charger. You can optionally use and a instead of the USB charger if you prefer, but I’ll leave that for you to explore; it’s definitely worth checking. Power over Ethernet network switch You can either have the charger (or network switch if you go for it) next to your Raspberry Pi rack or attached to it. I used rubber bands to keep the charger attached to the side of the case. It worked fine. With the USB cables plugged in, you are ready to start all those mini-computers! Connect the charger, and switch it on. Depending on the Raspberry Pi models that you use, they might take some time to boot, so be patient. Meanwhile, enjoy the LEDs flashing and fans starting. Connecting Through SSH If everything went well, you should be able to reach the Raspberry Pi devices through SSH. Give it a try by running the following from your computer: ssh pi@rpi01.local Introduce your password, and answer to add the device to the list of known hosts. Congrats! Your cluster is live now. yes You may want to run commands to check the hardware information. For example: : Information about the CPU architecture lscpu : File system disk space usage df -H : Partition information sudo fdisk -l : Amount of used, free and total amount of RAM free -m : Linux kernel information cat /proc/version Manual Configuration With raspi-config If you have one Raspberry Pi, you can connect to it through SSH as described above, and use the utility program to configure various settings. You can modify the WiFi connection ( ), change the hostname ( ) and user password ( ), and expand the filesystem ( ), among many other things. raspi-config S1 S4 S3 A1 Automated Configuration With Ansible If you have more than one Raspberry Pi in your cluster, you might want to automate the configuration process using a tool like . With Ansible, you can run a command on multiple machines without having to perform repetitive tasks. For example, let’s say we want to expand the filesystem on each Raspberry Pi. This can be done from the command line as follows: Ansible sudo raspi-config --expand-rootfs Without automation, you’d have to SSH to , run the command above, and end the SSH session. You’d have to repeat all these steps for , , , and so forth. Instead, you can simply tell Ansible to run the command for you on all the machines. Let’s see how to do this. rpi01.local rpi02.local pr03.local rp04.local You have to install Ansible on a that is connected to your local network. It can be one of the Raspberry Pi devices, your working laptop, or any other machine as long as it runs a Unix-based operating system like Linux or macOS. control node I happen to have an old laptop that I connected to my network, so I used it as the control node (I’ll show how to install a database with replication in the Raspberry Pi devices in a future article). repurposed as a dedicated database I won’t go through the instructions on installing Ansible since the process is different on different operating systems. Check the and install it on your laptop or any device that you want to assign as a control node. official documentation Before you start, I recommend generating an example configuration file that you can tweak later as you wish: sudo su
ansible-config init --disabled -t all > /etc/ansible/ansible.cfg
exit In this file, disable host key checking to simplify the process. Don’t do that in production environments! Change the following line: ;host_key_checking=True to this: host_key_checking=False Next, you need to define an inventory. This is a list of machines that you want to control with Ansible. The inventory is defined in the file. For example, you could add the following machines to the inventory using their IP addresses or hostnames: /etc/ansible/hosts [mymachines]
foo.example.com
bar.example.com
192.0.2.50
192.0.2.51 If the machines have some kind of pattern in their IP addresses or hostnames, you can alternatively use ranges. This is what you can do with your Raspberry Pi devices. Edit the file by adding the following to the end: /etc/ansible/hosts [rpis]
rpi[01-08].local Change the pattern to match your hostnames and numbers. This is equivalent to: [rpis]
rpi01.local
rpi02.local
rpi03.local
rpi04.local
rpi05.local
rpi06.local
rpi07.local
rpi08.local In this inventory, is an arbitrary name that you can use to refer to all the Raspberry Pi devices when running commands on them using Ansible. rpis You need to configure the SSH username that Ansible will use when connecting to the machines. Add the following to the file: /etc/ansible/hosts [rpis:vars]
ansible_user=pi Time to control de machines. A good start is to them: ping ansible rpis -m ping --ask-pass Type the SSH password. You should see in the output how the “ping” is answered by a “pong” for each machine (I’m showing only one here): rpi01.local | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3"
    },
    "changed": false,
    "ping": "pong"
} Let’s back to the filesystem expansion (although, I think nowadays this is not required anymore, let me know in the comments if you can confirm this). To perform this action on all the machines, run: ansible rpis -m shell -a "raspi-config --expand-rootfs" --become --ask-pass And as simple as that, all your Raspberry Pi devices have an expanded filesystem. This is a good time to update the system on all the machines: ansible rpis -m shell -a "apt update -y" --become --ask-pass
ansible rpis -m shell -a "apt upgrade -y" --become --ask-pass You can reboot all the devices as follows: ansible rpis -m shell -a "reboot" --become --ask-pass And once you are done and want to safely turn all the machines off, just run: ansible rpis -m shell -a "poweroff" --become --ask-pass What's Next? This is only the beginning. You now have a cluster of small computers ready to be controlled by Ansible. You can try setting up any kind of server software, including web servers or databases ( ). There also is much more about Ansible. see this example I merely scratched the surface here using , but you can for example create that contain the state in which you want your cluster to be. Explore the , and have fun! ad-hoc commands playbooks documentation Also published here

How to Build a 32-Core Raspberry Pi Cluster From Scratch

Cómo construir un clúster Raspberry Pi de 32 núcleos desde cero

Comment construire un cluster Raspberry Pi à 32 cœurs à partir de zéro

स्क्रैच से 32-कोर रास्पबेरी पाई क्लस्टर कैसे बनाएं

32 コアの Raspberry Pi クラスターをゼロから構築する方法

Como construir um cluster Raspberry Pi de 32 núcleos a partir do zero

Cách xây dựng cụm Raspberry Pi 32 lõi từ Scratch

如何从零开始构建 32 核 Raspberry Pi 集群

Using Metasploit to Attack Default SSH Username/Passwords The Lab Environment This is a simple brute force method to connect to a Unix machine using SSH in our pentesting lab. The target machine, a Raspberry Pi running the Kali Linux OS is up-to-date and no other changes were made to the operating system. SSH is enabled, but in reality, this can be any machine with SSH.  We are using common default usernames and passwords. The machine performing the exploit is Kali Linux on VMWare. The Target Machine The Raspberry Pi is also performing no other daily responsibilities so no additional setup on this machine is required for this test. SSH is enabled during the installation and the system is up-to-date using and . apt-update apt upgrade Getting the Target IP Address If you do not know the IP address of the target machine, you can confirm the IP address of the Raspberry Pi using the or command from the console. hostname -I ifconfig In this example, the IP address of our Raspberry Pi target machine is . You will need this later so write it down. 192.168.1.95 You are done with the Raspberry Pi. It is now just another server on a network doing normal computer things with SSH enabled on Port 22. A secure Linux machine serving up web pages and user accounts on the Internet. This can be any machine, but for this example, it is our target. Setting up the Exploit On our attacking Kali Linux machine, we need to set up some files and configure Metasploit to exploit the Raspberry Pi victim’s server. There is nothing complicated here, just some small attention to detail. To keep it simple, this exploit uses a list of custom usernames and a list of select passwords. Each username and password are on separate lines in their respective files. To keep this test short and interesting, the lists contain common default usernames and passwords for some Raspberry Pi distributions. You can use any dictionary for this exploit, but we are going to create a simple one for this example. Create Username and Password files Our target group of computers in our testing lab are Raspberry Pi’s. We know the usernames and passwords for this exploit are going to consist of default usernames and passwords specific to Raspberry Pi operating systems. You can use the standard Kali password lists like xxx.txt, but that will take a lot longer to run. The success of this exploit is banking on the fact that admins do not change the default login credentials. Using your favorite text editor, create a file containing these usernames. user.txt root admin kali raspberry pi support Feel free to add additional default usernames to this file. This is only an example of using some common default usernames on Raspberry Pi devices. Create a file containing the following passwords, one password per line: password.txt root toor pi kali admin raspberry password password123 Just like the username file, feel free to add additional default passwords to this file. This is only an example of using some common default passwords on Raspberry Pi devices. Save these two files to your local directory. In this example, we are using . /home/kali/data Run a Nmap Scan My homelab for this exploit has a lot of VMs, Raspberry Pi’s, and production machines in service. Most of these have open SSH ports. With this in mind and I’m never really sure how many open SSH ports there are on my network, I’m using the following command to get a feel for the landscape. The flag says only report on SSH and the flag lists only the ports that are open. Closed ports are not included in the output. -p 22 -open kali@Victim-Pi:~$ sudo nmap -p 22 -open 192.168.1.0/24 The results from our scan show that the ssh service is running (open) on a lot of machines. Now we narrow our focus and use Metasploit to exploit the ssh vulnerabilities. We are interested in the or address because that is a Raspberry Pi and the target of our attack. nmap Victim-Pi 192.168.1.95 Our attacking machine is the or kali-server 192.168.1.207 Raspberry Pi. Using Metasploit From the ( ) command line, launch Metasploit by typing . kali-server 192.1681.207 msfconsole Metasploit provides a search engine to help us select the best exploit to exploit SSH. Entering the command shows us all of the ssh options. search ssh Scan through the output for the ssh vulnerability. For this exploit we want to use Menu Item #21 — which uses brute-force SSH login credentials with our and files we created in . Note that your menu item number most likely will be different. ‘use auxiliary/scanner/ssh/ssh_login’ username.txt password.txt /home/kali/data Enter ‘use ‘ at the msf6 > prompt. You can also enter the menu number (for example: msf6> auxiliary/scanner/ssh/ssh_login use 21 Type and / . set USER_FILE /home/kali/data/username.txt set PASS_FILE home/kali/data/password.txt The next two options, stops execution when there is a successful username/password combination and prints all status messages to the console. set STOP_ON_SUCCESS true set VERBOSE true The command configures Metasploit to use the target machine. This is the same IP address (192.168.1.95) of the machine we issued the or commands earlier. set RHOSTS hostname -I ifconfig Use the command to view additional configuration options advanced You can change any of these options for your situation, but we want quick access to the shell so . set GATHERProof false All of our configuration options are set, run the command to start the exploit. exploit After several failed login attempts, notice the entry. This line reveals that there is a successful username of with a password of combination. [+] 192.168.1.95:22 — Success ‘pi:raspberry’ pi raspberry The option we set earlier tells Metasploit to stop the attack when there is a successful username/password combination. set STOP_ON_SUCCESS true Successful Login We have now successfully logged into the Victim-Pi machine using default login credentials. Type the command to see the active Metasploit sessions. sessions Connect to the current active session, enter the command. sessions 1 At this point, you can use Unix commands as if you were a regular user of the system. To get better control of our exploit type the command to get access to a bash shell. shell Now that you have access you can use Python, Perl, and other system resources to complete your exploit. bash shell How to Prevent this Type of SSH Attack on your Network. This is a brute force attack on a common vulnerability. To mitigate your exposure you can perform the following actions. Educate users on proper usernames and passwords Disable default username/passwords Disable SSH Prevent multiple login attempts Also Published Here

Attack Default SSH Username/Passwords Using Metasploit

At points in our lives, we all find ourselves falling into an inactive rut. We do nothing to improve ourselves or develop our skills, instead just coast through life and hope for the best. Sometimes we dig the rut even deeper and become – for lack of better words – a blob. "Speak for yourself, Scott!" I know; it's not exactly a fun thing to admit, but if you're like most people, there have been times when you haven't felt in control of your life. You've let yourself slide and didn't take the initiative to do anything about it. I know I have. Recently I've been learning about inaction's polar opposite. It's the force that drives people to take control of their lives; the motivation that flicks the switch, pulling us from the complacent darkness of inertia and into the glaring light of progress. That force is personal initiative. Perhaps you're someone who is particularly prone to rut-digging, or maybe you're at the bottom of a rut right now. Either way, let's talk about personal initiative and what it can do for you (hint: a lot). Today's Inspiration: Dre Baldwin Before I dive into this concept of personal initiative, I want to hear from the guy who brought this concept to my attention in the first place. is a former 9-year pro basketball player who traveled to no less than 8 countries in his career after walking on at an NCAA Division 3 school. Dre Baldwin He is now a full-time entrepreneur who has authored 29 books and performed 4 TEDxTalks on Discipline, Confidence, Mental Toughness & Personal Initiative. Dre has over 137,000 subscribers on YouTube, and his daily podcast has been downloaded over 3 million times. Work On Your Game Can you imagine writing 29 entire books? Not only that, but managing 29 books on top of public speaking, running a business, and maintaining a podcast? Before speaking to Dre, I knew was going to be a cracker – and it was. our conversation Dre's Winning Attitude The sports scene is rife with drama and scandal. For an industry that should be all about healthy competition and camaraderie, it often seems to be anything but – and that's why some athletes simply don't make the cut. They develop a weak attitude and fail to put their best selves forward. Dre is one of those people who decided from an early point in his career to do things at 110 percent capacity. When training for professional basketball – even before getting an offer or scholarship – he would train as though he had already made it. "I thought that's what any athlete would do. But what I realized very quickly was that not every athlete did this, because people were looking at me like they were surprised. I thought, 'Isn't this what anybody would do? You show up ready for your job – or at least, ready for the job that you want.' I thought that was a normal mindset." Evidently, Dre's attitude set him apart from the pack and helped him land a gig playing professional basketball in eight different countries. That's an incredible accomplishment, and it flowed into the next phase of his career – a motivational speaker and business coach in the areas of mental discipline. "My definition of a professional is the person who shows up every day and delivers regardless of how they feel. Because some days we're sick, some days we're tired. Sometimes, you don't feel like turning the mic on. You don't feel like writing another page for your book. But you're getting paid for it – it's your job. You got to show up and do the work." Dre’s Principles for Success With such an inspirational start to our interview, I was excited to pick Dre's brain on some of the principles he teaches in his books and podcasts. I highly recommend watching the if you'd like to hear his expertise on discipline, confidence, and mental toughness, but here's a brief overview: entire interview Principle 1: Discipline "This is the foundational point, I think, for any professional in anything. Because if you look at the dictionary definition of a professional, it's a person who gets paid to do something; an occupation. But my definition of a professional is the person who shows up every day and delivers regardless of how they feel." Principle 2: Confidence "If you think about the most confident people, they are usually very disciplined individuals. And why is that? It's because they're showing up, and they're doing the work, and they know that they are following their principles on a day-to-day basis; they have earned the right to be confident." Principle 3: Mental Toughness "Mental toughness is your willingness and ability to continue being disciplined and confident, despite the fact that following the program – following the rules, your discipline, and your confidence – have not yet produced the desired results. Do you look at it and say, 'How do I fix this'? Or you just throw your hands up, give up, and quit?" I've listened to hundreds of business podcasts and read many business books, but I've never heard anyone explain these concepts so succinctly or convincingly as Dre did. The three principles he outlined – discipline, confidence, and mental toughness – are essential for success in any field. They also lay the foundation for personal initiative. Personal Initiative, According to Dre "The way I describe personal initiative is being that go-getter – the person who goes and makes things happen instead of waiting for things to happen." Dre explained something that really struck a chord with me. Often, listening to motivational podcasts and reading books about discipline trick our brains into thinking we've accomplished something. We become so enveloped in the Stoic mindset that we forget to actually take action. "The three things we've talked about so far – discipline, confidence, mental toughness – you could do all of that by sitting in your seat and never doing anything. You can read about it all day, and watch YouTube, and listen to podcasts, and all that stuff. But personal initiative is taking that potential energy and turning it into kinetic energy; energy in motion." Feeling challenged? I did, too. I feel like so many people in our society are in the same position; we're inundated with information but not enough action. Especially in the business world, we want to know every single step before we start moving. "These days, how many people have a podcast? How many people write books, and how many people are making YouTube videos? Literally everybody is doing it. So many of us can get into what we call analysis by paralysis – we're just taking in all this information, and we don't feel like we know enough to take action yet." Oomph. Dre did not pull any punches, for which I was glad. So what is the alternative? How do you show personal initiative in this case? "The problem is that by the time you figure out what to do, the opportunity is gone. The options are gone, your vitality is gone. So I tell people all the time – you only need 10% of information to get started. Along the way, you will learn more. You're probably not going to get the perfect result with only 10% of information, but you make your self eligible to get to the perfect result." What Does the Research Say? After our interview, I was intrigued by this concept of personal initiative. Where does it come from? Was Dre the original penman or was it explored in business literature? Amazingly, the first few Google results were peer-reviewed papers. It's rare to find a business concept that hasn't been monetized to the moon. The I found was specific to social entrepreneurship. "Individuals with personal initiative are capable of using their prior knowledge, proactive and innovative and experience to be alert as they create social ventures that create social impact." first paper This makes a lot of sense to me; people with PI are the ones who start social movements and rally others to their cause. They don't passively comment from the sidelines or share an emotional article on Facebook. I then found a published in the Research in Organizational Behavior journal described personal initiative as "...a work behavior defined as self-starting and proactive that overcomes barriers to achieve a goal." 2001 paper Interesting – this sounds a lot like plain old initiative. So what makes it personal? Well, the same paper clarified that 'PI' isn't exclusive to work-related activities. "Personal initiative is seen to sharpen and partly modify the concepts of reciprocal determinism, organizational citizenship behavior, innovation, entrepreneurship, work performance, intrinsic motivation, and self-regulation." So, it would seem that taking personal initiative is akin to being a proactive problem solver with a can-do attitude. It's about stepping up and doing something, instead of waiting for someone else to do it first. Three Behaviors of Personal Initiative Here's a from the 2001 paper: simple visual As you can see, there are three main behaviors shown by people with personal initiative: Rather than waiting to be acted upon, people with PI take the bull by the horns and initiate action. Self-starting. As Dre said, people with PI don't give up when success seems out of reach. They take a new angle or try a different approach. Persistent. Rather than sitting back and reacting to circumstances, people with PI are always on the lookout for new opportunities or ways to improve things. Proactive. This is the type of conversation that excites me. It means we don't need to give in to our ruts, and we can always find ways to improve our lives and businesses. Sometimes, an attitude adjustment is all it takes to get unstuck. Solid Strategies for Embracing Personal Initiative To wrap up the newsletter, let's dive deeper into the idea of personal initiative and how you can use it to empower your life. What are the takeaway strategies you can start implementing today? 1. Understand the power of personal initiative and how it can benefit you. Personal initiative is about being proactive rather than reactive (or worse, passive). When you take charge of your life, you're in the driver's seat – you get to call the shots. This can be a powerful feeling, and it can translate into big benefits in all aspects of your life. By reading this far into the article, you're already taking steps to understand and embrace personal initiative. As you continue to learn more about it and put its principles into practice, your life will become richer and more fulfilling. 2. Identify your weaknesses. I'd love to say this journey is going to be easy, but in all honesty, it's not something you can simply launch into unawares. Take some time to do this first: Write down all of the areas in your life where you've chosen inaction. Is there a goal you've been sleeping on? Have you got a business idea you've been procrastinating? Maybe you've been wanting to learn a new skill, but keep putting it off. Now ask yourself why you haven't acted in these areas. What's holding you back? Fear of failure, fear of the unknown, lack of confidence or simply not knowing where to start can all be factors. Once you know what your weaknesses are, you can start to address them and build up your personal initiative muscle. 3. Take a content sabbatical. As I discussed with Dre, analysis paralysis is a very real threat in 2022. We are inundated with books on habit building, fitness, mental discipline, goal setting, and so on, and we refuse to take action until we've learned it all. But it's impossible to learn everything – so take Dre's advice, and settle for knowing just 10 percent. Take a break from your podcast, shut your book, and spend some time putting what you've learned into practice. 4. Do something a bit crazy. Sometimes, the perfect remedy for getting out of a rut is to do something drastic. Not dangerous or reckless, but something that will shake up your daily routine and get you thinking out of the box. Choose something from your list of weaknesses and take action on it – even if that means starting small. Just make sure you take some form of action, however small! Wrap-Up If you're struggling with inaction right now, I hope this article has given you something different to think about. You've likely been slamming yourself with podcasts about productivity and growth – and I know how suffocating that can feel. Instead, do something daring. Take some personal initiative in an area of your life where you've been stuck. And if you're still feeling lost after that, remember Dre's words: "You're probably not going to get the perfect result with only 10% of information, but you make yourself eligible to get to the perfect result." Also Published Here Watch the full interview . Until next time! here

Taking Personal Initiative

How to choose the right I2C chips. Or the hidden software problem of choosing hardware modules IoT-devices LLC constantly promote the use of I2C bus as one of the best serial digital interfaces. The I2C bus offers all the necessary functions: a simple physical interface: the SDA data and SCL synchronization signals require only two wires to connect to the bus; the addressing of devices on the bus with unique 7-bit addresses; identification of devices on the bus by their address or by unique identifiers (if provided by the chip manufacturer); hot device plugging / unplugging like Plug & Play; the unit is powered by the bus or by each module’s own power supply; the support for different supply voltages of devices on the bus (provided that the signals are matched to the voltage level); an advanced infrastructure of amplifiers, repeaters, splitters and multiplexers to build complex topologies offered by chip manufacturers; All that allows about a hundred devices to be connected to the controller on a single interface at the same time. The I/O port budget of the main controller is minimal when the I2C bus is used to connect the sensors. Sensors or actuators might be on an extension cord, or all the chips might be concentrated on one module. Or all chips can be focused on one module. The master controller and slave devices can be powered independently. Or all devices on the bus can be powered from a common source. The I2C is supported by the vast majority of microelectronics manufacturers. All popular controllers, IoT / Smart Home platforms, and related development environments are compatible with the bus. Most IoT devices support the I2C interface as basic. Moreover, the support of the I2C bus is usually a decisive factor in the selection of chips in our projects. But any system has not only advantages. There are also shortcomings and hidden problems that we reveal in the publications. Today we would like to talk about the software problem of choosing the right hardware sensors with I2C bus support. We will not go into the theory, but rather suggest a practical example using our devices. Let’s start with the popular radiation sensor module . GGreg20 Example №1. GGreg20 and I2C GGreg20 and I2C From time to time we are asked if it would be better to equip the GGreg20 module with the I2C interface and offer such a product as an alternative to the product with a pulse output, which is now GGreg20_V3. In short, no. Let’s try to justify our opinion in more detail. We really like the I2C bus. We, moreover, already have an I2C interface splitter module, I2CHUB, which would be well suited to a hypothetical GGreg20 with I2C interface. So we can take a budget microcontroller – a companion like STM32, which must perform the necessary pulse calculations and give calculated values of the power and dose of ionizing radiation to the main controller at a low level via I2C interface. But let’s ask ourselves how many common and very popular IoT platforms and microcontrollers will have driver support for such an I2C sensor? The answer will be disappointing since it is not an industrial sensor with a huge sales market. Certainly, our company needs everyone to be able to connect our sensors. It is our customers who must choose the type of controller or platform. We need to provide versatility for Arduino, ESP32 / ESP8266, Raspberry Pi, or for NodeMCU, Node-RED and ESPHome in Home Assistant, and many other IoT development environments that we might not have even heard of. GGreg20 is now supported by any controller, development environment, and IoT platform, precisely because it has a versatile pulse output. If we equipped the GGreg20 with an I2C interface, we would have a completely different result. *. What if you make two interfaces on the GGreg20 module at once – pulse output and I2C?* Note It would be very convenient, but in this case we believe that these costs at the expense of customers would be unjustified. The companion controller occupies a certain area on the module board. The I2C bus takes up twice as many controller ports as the pulse output. All this significantly increases the unit cost of the product. While the Pulse interface takes up only one GPIO controller with an interrupt handler and is much easier to program. And if we talk about maximum simplification, the GGreg20 module can work without a controller at all. The user can measure radiation (in circumstances that require it) only with a clock to record the measurement time in minutes. We will next consider another example of two similar devices. They both have an I2C interface, but different application perspectives. Example №2. I2CUI3, I2CUI4 and I2C We first developed – a useful and reliable product. It is a universal module of user interfaces with the I2C interface, which provides input of user instructions with the help of five navigation buttons and output of data to the RGB LED and the buzzer about the status or events of the IoT device. It is based on the 8-bit NXP PCA9538 port expander. For many years we have been using this chip for various tasks, including as the main component of the I2CUI3 module. The PCA9538 port expander is convenient, as it works semi-automatically after power supply and for some tasks does not require pre-programming at all, and therefore can work even without the main microcontroller. I2CUI3 And then it became clear that we need not 8-bit, but 16-bit similar module for certain tasks. So we created a new product with an I2C interface – I2CUI4 module based on the MCP23017 port expander chip. For the new we could use NXP’s older expander in the line. They have several 16-bit expander chips like PCA6416, PCA9539, PCA9575, PCA9673. But there are no official libraries for any of the chips either on the arduino.cc site or on the esphome.io site. There are also no drivers for the NodeMCU firmware. I2CUI4, There are only a few libraries for PCA9539 on Github, but neither Adafruit nor Seeed Studio has drivers for any NXP chip. That is why the new product I2CUI4 is compatible with common platforms and has probably the most popular chip MCP23017 from Microchip Technology with I2C interface. Thanks to that, our MCP23017-based product can boast a wide range of support by Arduino, NodeMCU, ESPHome / Home Assistant, Node-RED, Blynk, MicroPython, Raspberry Pi, STM32, and other brands. GitHub has hundreds of repositories with drivers in C / C ++, Python, JS, Lua, and other languages. Conclusion We gave two examples of identifying and solving the problem of driver support for devices equipped with an I2C interface from our own experience. Unless you plan to provide on your own driver support for an I2C device you are about to buy, please pay attention to the hidden external risks described in this publication. You should choose a device, module, or chip with an I2C interface, which, in addition to other factors, will have the widest driver support among third-party systems. Special attention concerning compatibility and support should be given to the target microcontrollers, platforms, development environments. You have to be sure that all of these systems will support your chip before using it in your designs. We have used these principles to develop two excellent products, GGreg20 and I2CUI4, to minimize the risks and avoid the problems mentioned above. We hope you find this material useful. Thank you for your attention. Original Source: https://iot-devices.com.ua/en/how-to-choose-the-right-i2c-chips-en/ Ukrainian article translation: https://iot-devices.com.ua/how-to-choose-the-right-i2c-chips-ukr/ Tags: I2C, DriverSupport, IoT, GGreg20_V3, I2CUI4_V1, MCP23017, PCA9538, IO, IoT-devices

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