Updated Article!
I am quite happy with the 5 port Com Hat I made for Raspberry PI, but I want to use a STM32F405RG and maximize usage of all it’s IO capabilities. This will be an upgraded Hat with a few more features included:
- Replace F105 with the faster and more capable F405 including 1Mb Flash, 192Kb SRAM, ticking at 168Mhz with an ARM 32-bit M4 core. This change will allow Python and .NET to be used as well.
- Add a RTC w/battery connector.
- Add a SPI Flash
- Add a SD/TF Card. I will use a 4 bit MMC version.
- 2 x CAN ports as before
- 4 x Serial ports. 2xRS485, 2x RS232 or TTL. My first thought is 2 x RS485, 2 x RS232 and 1 x TTL, but lets see.
- 1 x SPI port
- 1 x I2C ports
- SPI, I2C and available pins as separate extension port. Maybe even throw in a UART TTL here.
- 1 x USB
- Limit leds to 1 or 2 pin’s max. We can signal through blink sequences.
I have the pins to do this, so it remains to se if the space of a Raspberry PI Hat will allow for this. I will need to use 3 sides with JST Micro connectors for this one.
PSU here will either be USB or RPI Connector, but I will add a 2 pin 5V power as well.