Meet the CannedPi hardware! This simple (and not prefectly designed) Raspberry PI Hat contains an STM32G4 microcontroller which can interface with the USB port of your Pi.
Why would I create such a Rube Goldberg design??
- I wanted a HAT that would provide provide solid 5V power from a ~12V power input. This board has a 4A SMPS that provides more than enough juice for even a power hungry Pi4.
- I wanted the option of running both scripts on the Pi (Python-CAN, C applications, etc) while also having the ability to run real-time CAN on the embedded chip as needed.
- Wanted an "all-in-one" form factor for mounting on LCD displays and other small cases
- For LIN you really need the real time microcontroller
- I wanted to prove I could do it. Now that I feel I've achived my goal I decided to share it wth everyone
- The 26-pin header provides access to all 3 CAN channels, the LIN channel, 12V, 5V, 3.3V and a few GPIO from both the PI and the SMT32G4. Why a 26-pin? Other CAN tools I'm using also utilize this header and I didn't feel like making new harnesses. Besides, it's a nice form factor for getting a lot of I/O and there are cables available on Amazon.
This design is provided in KiCad 6.0
It has not been EMI or EMC tested. I am not a hardware engineer so I can't ensure that there aren't some design flaws. I've sanity tested the prototypes and they seem to be stable and perform as expected.