• Home Automation, Raspberry Pi
      2 min | 146

      #CC2531 & Raspberry Pi: Philips HUE bridge v1 replacement

      Home Automation, Raspberry Pi | 2 min | 146

      philips bridge
      philips hue
      raspberry pi 4b

      As you may know, the Philips Hue Bridge v1 has support until April 30, 2020. This means, after April 30, 2020, no software updates will be made available and it will not connect to the online services. However, you can still control it locally via the "dedicated Philips Hue Bridge v1 app". Nevertheless, you have a device (connected to your network) that can be a "treasure" for hackers (MITM-Attacks), and the "dedicated Philips Hue Bridge v1 app" will disappear shortly! (...

    • Home Automation, Raspberry Pi
      6 min | 8268

      #Raspberry Pi: Controlling Philips HUE Lights (ZigBee & CC2531)

      Home Automation, Raspberry Pi | 6 min | 8268

      home assistant
      home automation
      philips hue

      This article extends the tutorial about Hass.io and the Xiaomi Aqara Sensors that I've published months ago. That tutorial is part of the series of articles about Zigbee and the Rasbperry Pi using the CC2531 USB dongle. Here are the links:

    • Raspberry Pi, Single-board Computers
      4 min | 1385

      #Raspberry Pi: Encrypt (and save) Docker credentials

      Raspberry Pi, Single-board Computers | 4 min | 1385

      docker enviroments
      docker hub
      docker registry
      embedded systems
      raspberry pi

      Usually, I login to different Docker registries (local, Docker Hub, etc.) with a computer running Ubuntu. I execute once docker login, then I enter the username and password, and after restarting the system, the access data is still available. That means, I write the credentials only once. But, on the Raspberry Pi, it was different until today: I needed to write the login credentials every time I booted the board.

      This article helps you to install the needed tools to save Docker login credentials on the Raspberry Pi, but not as plain text, so that the next time that you reboot the Raspberry t...

    • Raspberry Pi
      6 min | 5617

      #Raspberry Pi 4B: Sometimes it's cool to be hot -or warm, to be exact ;)-

      Raspberry Pi | 6 min | 5617

      ice tower cooler
      n-queens problem
      raspberry pi 4b
      temperature test

      This article is the last in a series of three articles that evaluates the performance of the Raspberry Pi 4B. This time the performance of Raspbian with standard kernel (4.19.y) will be evaluated with and without active cooling using two types of heatsinks. The other articles in the series are the following:

      1. The first article is about comparing the Raspberry Pi 4B and 3B+ performances:
      2. The second article compares the Raspberry Pi 4B runn...
    • Raspberry Pi, Real Time Systems
      7 min | 18305

      #Raspberry Pi 4B: Real-Time System using Preempt-RT (kernel 4.19.y)

      Raspberry Pi, Real Time Systems | 7 min | 18305

      preempt-rt kernel
      raspberry pi 4b
      raspbian buster
      real time system

      The Preempt-RT patching article is one of the most visited articles in my blog. However, that article needed a small update: Raspberry Pi 4B is out there and with Raspbian Buster, a new version of kernel is available: 4.19.y.

      I also uploaded the compiled and patched kernel to lemariva/RT-Tools-RPi. You can follow all these steps and compile the kernel by yourself or you can download the files from the repository and deploy the kernel on your Raspberry Pi 4B.

      This tutorial is the second of a...

    • Deals, Raspberry Pi
      3 min | 11672

      #Raspberry Pi: Displaying images on an E-Ink screen

      Deals, Raspberry Pi | 3 min | 11672

      e-ink display
      raspberry pi

      Last week, I published an article about the Raspberry Pi and an e-ink display:

      This time, this tutorial is about processing and displaying images on the 7.5" e-ink screen as shown in Fig. 1b.

      Waveshare® 7.5" E-ink Screen connected to a Raspberry Pi
      Fig. 1a: E-ink Screen connected to a RPi
      running ePaperWidgets
      Fig. 1b: Banggood's 13th anniversary
      original image here

      Hardware & Software

      You find here a list of hardware and software that you could use for ...

    • Raspberry Pi
      4 min | 8451

      #Raspberry Pi 4B: How much faster is the new CPU?

      Raspberry Pi | 4 min | 8451

      n-queens problem
      raspberry pi 3 B plus
      raspberry pi 4b

      On July 4th, I ordered a Raspberry Pi 4B from Reichelt. On July 17th, I received the board, but it was broken, and a month later, finally I received a new board that seems to work OK :).

      The new Raspberry Pi 4B has a lot of upgrades and one of the most important ones is the RAM: You can choose between three models (1GB, 2GB and 4GB). But, another main change is the CPU and the RAM bus: they changed from a Cortex-A53 64-bit (3B+/3A+) to a Cortex-A72 64-bit, both ARMv8, and from LPDDR2 SDRAM...

    • Raspberry Pi
      7 min | 13725

      #Raspberry Pi: an E-Paper display with Widgets

      Raspberry Pi | 7 min | 13725

      e-ink display
      google apis
      google calendar
      raspberry pi
      raspberry pi zero

      E-paper or e-ink displays are becoming more common in recent days. You can find them e.g. on readers, clocks and sensors. Thus, I looked for an e-ink display for the Raspberry Pi and I found the Waveshare® 7.5" E-ink Screen.

      There are many projects with an e-ink display and the Raspberry Pi, but I first tried with an ESP32 and MicroPython. That solution didn't work (something was not working with the reset voltage - too much signal noise). So, that remains a work in progress and I wi...

    • Home Automation, Raspberry Pi
      3 min | 24332

      #Zigbee: Flashing a CC2531 dongle using a Raspberry Pi

      Home Automation, Raspberry Pi | 3 min | 24332

      aqara sensors
      door sensor
      home assistant
      raspberry pi
      xiaomi gateway
      xiaomi sensors

      Last April, I published a tutorial about connecting the Aqara sensors to a Raspberry Pi without using the Xiaomi Gateway. To make that possible, I needed a CC Debugger to flash the TI CC2531 Zigbee Dongle. This debugger was used only one time, and then the Zigbee-USB dongle worked without any problem.

      In this article, I will cover a way to flash the CC2531 without the CC Debugger. This reduces project costs (about $10 for debugger + cable adapters) and waitin...

    • Raspberry Pi
      2 min | 5840

      #Raspberry Pi 4B: Where were the quality controls?

      Raspberry Pi | 2 min | 5840

      board broken
      capacitor broken
      quality control failed
      quality problems
      raspberry pi
      raspberry pi 4b
      tantalum capacitor

      On July 4th, I ordered a Raspberry Pi 4B. To be honest, I really didn't/don't need a new Raspberry Pi, I don't have any specific task for it, but I saw some cool stuff on the Internet, and I said: Ok, I need one! Thus, I bought the 4GB model on Reichelt. The expected delivery date was on July 10th but, I had to wait a little longer and I got it on July 17th! Everything was ok, and I got the following closed and sealed box (see Fig. 1):

      Fig. 1: Box of the Raspberry Pi Model 4B (4GB RAM)

      But, as soon as I opened the box, my joy faded! :( With a quick visual control, I checked tha...