• 05
      Nov - 2019

      Product Reviews
      5 min | 4015

      #Xiaomi CMSXJ11A: an IP-Camera with built-in battery

      Product Reviews | 5 min | 4015


      camera
      ip camera
      product review
      security
      xiaomi
      xiaomi ecosystem

      This article evaluates three low budget Wi-Fi cameras that I buy from e.g. banggood.com and aliexpress.com but I will focus most of the analysis on my last acquisition the XIAOMI Mijia CMSXJ11A.

      All cameras in this review are Xiaomi (not exactly built by Xiaomi) and can be connected to the application Mi Home (apple/android). Moreover, you need to select the region to China (Mainland) in the application, otherwise you are not going to find the devices. This has a main disadvantage: the servers are in China Mainland. The documentation is also still in Chinese, and sometimes the cameras talk to ...

    • 16
      Oct - 2019

      Product Reviews, Single-board Computers
      6 min | 11487

      #Orange Pi Zero LTS: An 'upgraded' alternative to the old Raspberry Pis

      Product Reviews, Single-board Computers | 6 min | 11487


      armbian buster
      benchmark
      development boards
      n-queens problem
      performance
      raspberry pi

      The Allwinner H2+, which integrates four ARM-Cortex A7 cores that can clock up to 1.2GHz, is powering the Orange Pi Zero LTS. The tiny board, which measures just 52 x 46 mm, features 802.11 b/g/n Wi-Fi, Ethernet, up to 512 MB of RAM, USB 2.0 Type-A and a microSD card slot. There is also a 26-pin unpopulated GPIO header along with a 13-pin header for a headphone, USB 2.0, TV-out, microphone and IR signals.

      This board is the next generation of the Orange Pi Zero that was first launched in November 2016 for $7 and up. It should solve various issues with the Allwinner XR819 WiFi module that many ...

    • 23
      Sep - 2019

      Product Reviews, Single-board Computers
      6 min | 5507

      #Rock Pi S: a tinier version of the Raspberry Pi with Alexa functionalities

      Product Reviews, Single-board Computers | 6 min | 5507


      Alexa functionalities
      debian stretch
      development boards
      OS image
      performance
      Radxy
      Rock Pi S

      Radxy, the company behind the Rock Pi 4 is back! A couple of days ago, I've received the Rock Pi S (see Fig. 1), a miniature developer board that measures just 38 x 38 mm. The board is powered by the Rockchip RK3308 SoC, which integrates four 64-bit ARM Cortex-A35 cores (Ultra-High-Efficiency). Each of the cores reaches up to 1.3 GHz. The SoC also has a built-in voice activity detector (VAD) for use with IoT and smart voice applications.

      Despite its tiny size, the Rock Pi S includes a 26-pin GPIO header along with a 26-pin audio/voice header and a microSD card reader. Additionally, the Rock P...

    • 15
      Sep - 2019

      MicroPython
      6 min | 8897

      #MicroPython: Taking photos with an ESP32

      MicroPython | 6 min | 8897


      camera
      esp32
      esp32 projects
      esp32-cam
      micropython
      micropython extensions

      Last year, I bought an ESP32-CAM board from Banggood and I wanted to use it with MicroPython. The board has an OV2640 without any chip (buffer) between the ESP32 and the camera. There are many implementation for Arduino or directly using Espressif, but I wanted to use MicroPython. Thus, the only solution was to use the I2S interface, but I didn't have time to write the driver. Thus, I put the project on hold. However, last week I was searching between the ESP32 boards that I have, I found the board again, and I also found that tsaarni has written the driver for MicroPython.

      This tutorial is a...

    • 06
      Sep - 2019

      Raspberry Pi, Real Time Systems
      7 min | 15435

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

      Raspberry Pi, Real Time Systems | 7 min | 15435


      performance
      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 series of three that evaluate the performance of the Raspberry Pi 4B. This time the performance of the s...

    • 04
      Sep - 2019

      Deals
      3 min | 1414

      #Banggood 13th Anniversary: be ready for the BIG Sales!

      Deals | 3 min | 1414


      deals
      discounts
      e-ink display
      electronics
      esp32

      Banggood is celebrating its 13th anniversary by launching a grand sales that takes place between the dates August 27th and September 18th (my birthday! :)).

      Fig. 1: Banggood's 13th anniversary image on an E-ink screen (tutorial)

      Banggood, founded in 2006 and located in Guangzhou, is the fourth largest international e-commerce retailer in China. By running its website www.banggood.com and smartphone applications, Banggood sells more than 500,000 types of products to the United States, Great Britain, Germany, France, Spain, Italy, Australia, Russia, Japan and ma...

    • 03
      Sep - 2019

      Cloud Platforms
      7 min | 5044

      #GCP: Running OpenProject almost FREE

      Cloud Platforms | 7 min | 5044


      docker
      docker-compose
      google cloud platform
      management software
      nginx
      openproject

      The last days, I was looking for an online project management tool with bug tracking system. The best platform that I know is Jira from Atlassian. Jira offers a bug tracking and agile project management, however, it costs between $8.33 and $10 (annual/monthly payment) for the standard version with under 10 accounts. We use Jira in Finealyze and I am very happy with it, but I was looking for a free alternative for myself. Then, I found OpenProject, which describes itself as "the leading open source project management software".

      OpenProject is offered in three different ways: Community, Cloud an...

    • 27
      Aug - 2019

      Raspberry Pi
      3 min | 11382

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

      Raspberry Pi | 3 min | 11382


      anniversary
      banggood
      deals
      e-ink display
      python
      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 this tutorial:

      E-ink Screen
      • Waveshare® ...
    • 25
      Aug - 2019

      Raspberry Pi
      4 min | 8308

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

      Raspberry Pi | 4 min | 8308


      benchmark
      buster
      jupyter
      n-queens problem
      performance
      raspberry pi 3 B plus
      raspberry pi 4b
      raspbian

      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 to LPDDR4 SDRAM. Thus, the CPU clock was increased to 1.5GHz (0.1GHz more) and the memory frequency to 2...

    • 21
      Aug - 2019

      Raspberry Pi
      7 min | 13375

      #Raspberry Pi: an E-Paper display with Widgets

      Raspberry Pi | 7 min | 13375


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

      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 will use this board. But now, in this tutorial, I uploaded a solution for the Raspberry Pi.

       Waveshare® 7.5" E-ink Screen connected to a Raspberry Pi
      Fig. 1: Wa...
    • 20
      Aug - 2019

      MicroPython
      4 min | 10659

      #MicroPython: VSCode IntelliSense, Autocompletion & Linting capabilities

      MicroPython | 4 min | 10659


      autocomplete
      esp32
      esp8266
      intellisense
      micropython
      pymakr
      visual studio code
      vscode
      wemos

      Last December, I wrote an article telling you that I was switching from Atom.io to Visual Studio Code to program MicroPython. Nowadays, I'm still using VSCode and the PyMakr extension. The latter enables the communication to a board running MicroPython using the built-in command line REPL. Thus, I can run a single file on my board, sync my entire project or directly type and execute commands using the Terminal on VSCode. However, I was missing some of the main features of VSCode, namely IntelliSense, autocompletion, and linting capabilities. Last month, BradenM contacted me and told me that he...

    • 13
      Aug - 2019

      Home Automation, Raspberry Pi
      3 min | 21664

      #Zigbee: Flashing a CC2531 dongle using a Raspberry Pi

      Home Automation, Raspberry Pi | 3 min | 21664


      aqara
      aqara sensors
      door sensor
      home assistant
      mqtt
      pir
      raspberry pi
      xiaomi gateway
      xiaomi sensors
      zigbee

      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 waiting time. Usually, you wait 30 days to get a low cost version of the debugger (using the cheapest shipping option). Let's start!

      Hardware

      ...
    • 02
      Aug - 2019

      Raspberry Pi
      2 min | 5805

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

      Raspberry Pi | 2 min | 5805


      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):

      raspberry_pi_box-min.jpg
      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...

    • 21
      Jul - 2019

      General, MicroPython, Miscellaneous
      1 min | 1826

      #Collector: Things that I recently bought - XIAOMI Wowstick & ESP32 8MB PSRAM

      General, MicroPython, Miscellaneous | 1 min | 1826


      development boards
      electric screw driver
      esp32
      esp32 8mb psram
      micropython
      misc article
      xiaomi wowstick

      This is a really misc. small article. Two month ago, I bought on Banggood two articles that I wanted to show you, but this time, these are not connected to an application, code or a detailed product review. This is only a misc. article to describe my purchase: The Xiaomi Wowstick Screw Driver and the TTGO ESP32 WROVER with 8MB PSRAM.

      Hardware

      Xiaomi Wowstick

      If you are looking for a very small electric screw driver, then the Xiaomi Wowstick is an option for you. It includes everything that you need except the batteries. You need two AAA batteries and you can start disarming toys, clocks, cell...

    • 14
      Jul - 2019

      General, Product Reviews
      5 min | 2438

      #Timeular: Tracking your time using an Octahedron

      General, Product Reviews | 5 min | 2438


      access to data
      bluetooth
      getting things done
      octahedron
      product review
      time tracker
      time tracking system
      timeular

      First of all, this article is a product review which was/is not supported by Timeular GmbH or similar. I bought the product two weeks ago, because I wanted to test it. I missed out the Kickstarter campaign (2016) and the regular price for the octahedron was too expensive for me.

      Timeular application: Analytics Dashboard
      Fig. 1: Timeular application

      This summer, the tracker is on sale with up to 50% discount and I bought the basic plan. I got an octahedron -called tracker- which connects to the Timeular application (Mac, Win...