• Deals
      1 min | 584

      #Elfter im Elften: Singles’ Day Deals (11.11 > single)

      Deals | 1 min | 584


      banggood
      deals
      discounts
      shopping day

      Today is Singles' Day or "Guanggun Jie" in Chinese, which is a popular shopping festival among young Chinese people, who celebrate their pride of being single! Thus, I got some discount codes from Banggood for Today and I'm publishing them here:

      This section is new in LeMaRiva|Tech and I will update it every day with new discount codes! I receive a list every day with new codes and I will use some analytics to select the best offers for you and automatically publish them there. Stay tuned!

      I cannot guarantee that all codes I published on this list work. I analyze the data (p...
    • Raspberry Pi
      6 min | 5597

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

      Raspberry Pi | 6 min | 5597


      heatsink
      ice tower cooler
      n-queens problem
      performance
      python
      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...
    • Product Reviews
      5 min | 4364

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

      Product Reviews | 5 min | 4364


      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 disa...

    • Product Reviews, Single-board Computers
      6 min | 12315

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

      Product Reviews, Single-board Computers | 6 min | 12315


      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 th...

    • Product Reviews, Single-board Computers
      6 min | 5812

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

      Product Reviews, Single-board Computers | 6 min | 5812


      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 in...

    • MicroPython
      6 min | 10449

      #MicroPython: Taking photos with an ESP32

      MicroPython | 6 min | 10449


      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,...

    • Raspberry Pi, Real Time Systems
      7 min | 17945

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

      Raspberry Pi, Real Time Systems | 7 min | 17945


      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...

    • Deals
      3 min | 1432

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

      Deals | 3 min | 1432


      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...

    • Cloud Platforms
      7 min | 5226

      #GCP: Running OpenProject almost FREE

      Cloud Platforms | 7 min | 5226


      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...