Anim4Bot

The Raspberry Pi is flashed with the Raspbian OS (quick start guide available here).

The STM32 is flashed with the RTOS ChibiOS. ChibiOS is compact, fast and open source OS : Perfect for me !

STM32F4 Discovery Board

I modified the power connector of the Pi in order to connect it with another connector. As you can see on the architecture document, I will use a small 3.7v Li-Po battery for the Pi and the STM32 with a special power supply (PTN04050C). So I soldered a JST connector with cables :

Brain Power Supply

The Raspberry Pi will will equipped with a “smart switch”. As you are running a Linux on it and a SD-Card, you can not unplug the Pi as you wish. If you shut off your Pi while it is writing on the SD-Card, you might corrupt this one… And you will have to flash it again… 😦

So to prevent this a found what I call a “smart switch” from Mausberry Circuits :

Smart switch

With this switch, you only have to install a small script on the Pi, and that’s it 😉 You can now power ON/OFF your Pi safely !

Concerning the STM32, I can directly use the 5v pin, so i don’t need do modify the board. The STM32 can be shut-down directly without special precaution, so no problem as for the Pi.