Embedded product with Raspberry Pi Compute Module

Raspberry Pi is a good solution for creating low-cost, powerful embedded devices when you have no need of self powered solution.

I had to create a such device recently to make a programming machine for my IoT devices. I was looking for a compact solution, powered with PoE, industrial grade, able to run a Java program and host a custom HAT with my home-made chip programmer.

Here you see a picture of the first prototype of this product with the different components visible: The green board is a Rapsberry Pi compute module CM3+ with 16GB eMMc flash drive. The blue motherboard is a Waveshare PoE board for CM3+. The Black board is my custom HAT hosting the programming solution based on a STM32.

In this post, I’ll detail a bit these different components and the way they are configured to illustrate how to easily make a such system alive.

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Pi Day – Sigma Lambda Pi

Sigma Lambda Pi is the perfect thing to talk about on the 3/14 Pi day!

This crazy machine is a 16 Raspberry Pi-4 cluster in a 2U server rack, set to execute FaaS (Function as a Service) with a green-it approach. Don’t make a dream of Raspberry-Pi high performance demonstration, you will be disappointed and it’s not the purpose of this project. This is not a commercial product, the objective of the company who made it, was research, team building and team skills improvement. This has been made by friends of my, working at Be|ys, a team of 9 people, under the lead of Christophe Prugnaud. They made a demo of it during the Clermont’Tech Api Hour #46, the video will be soon accessible.

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Cheap TFT / LCD touch screen for RaspberryPi with Jessy

TFT screen on a raspberryPi

TFT screen on a raspberryPi

This week I had to play with some TFT screen for RapberryPi for making a prototype for a local company. You can find many TFT screen on Internet but most of them are not coming with a nice fresh documentation for being use and it is kickly a mess to get it start with them. I ordered different one having the same 3.2” size matching my need and got 2 of them for starting tests.

This post details how to use a such screen for displaying a picture on it from a console line.

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Get computers for less than $15

domino.io

domino.io

Announced in 2015 and mostly delivered in 2016, the 9$+ computers are now a reality. The first one  to be delivered was Domino.io with a price of 14$ it is actually the most expensive device but also one with a nice list of addon. The kickstarter campain was a success even if it raised only 46K$.

CHIP was in the same period of time a great success with 2M$ raised on Kickstarter for 50K requested. And actually it still incredible to me to reach a such cheap price for a device with a such complexity.

Last but not least, the famous RaspberryPI zero is just starting to be distributed at the incredible price of $5 and is actually impossible to obtained under $20 on ebay auctions.

As a owner of these 3 different platform, I will publish in this post the difference we have between them and what we can expect from them.

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RF433 – Raspberry PI GPIO kernel driver for interrupt management

You may have read some of my post about RF433 and Raspberry PI. Basically with RPI 1, I was using wiringPi interrupt handler to manage the RF433 decoding. The problem is that with RPI2 and RPI B+ the delay to take an interrupt that was becomes unpredictable. And the timing constraints are not respected. As a consequence part of the messages are loss because for these delay.

One of the solution (the software one) is to be more efficient to proceed the interrupts and the way to do this is to compile a kernel driver for directly handling the interrupts. This is what this post is about. This comes to complete the RFRPI code and associated hardware. A complete source code and software for using it is on the rfrpi bitbucket repository.

Challenge of the coming days : write a kernel driver to manage interruption quicker on a raspberry pi 2. I’m happy to find a lot of example on Internet and in particular this one, that is really looking like what I’m trying to do. This post is describing all the step needed to do this.

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Get start with the SigRPI Shield

Raspberry PI Shiel Hat standard

Raspberry PI Shiel Hat standard

The SigRPI shield is a HAT standard board providing SigFox connectivity to your Raspberry PI. As it is not certified for this network it can’t be used in production for this usage, but you can use it as a long range RF that does not need certification. I will later details this with a project related to this function.

By-the-way, the purpose of this board is to let you play easily with sigfox. The raspberry-pi offering a really efficient way to code and to make prototypes.

The shield comes with TD1204 (including accelerometer & GPS) of TD1208 (sigfox modem). You can use it with the standard firmware or upload your own one.

The shield can be ordered in the shop section : here

This posts details how to setup it and use it.

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