An early mockup indicate I can manage 15 connector on a Hat with USB, but I will have to remove the external power connector and one of the connectors are CAN1, meaning the actual number of sensors are 14 connectors. If I dropped I2C and SPI I could just about manage 16 Analogue/Digital sensors, but I think 3 x SPI, 3 x I2C and 8 x Analogue/Digital is more optional. And, as always – if I need more I can add another board. I also think I can add the power connector back by moved led’s into the board. Will be interesting to see what the end result will be here.
I like these early mock-up’s because they give me a fast reality check. But, it is one more to come – all these channels will require TVS diodes and passive components etc – this Hat will be dense to route, meaning that I might need to sacrifice a few channels on the way – that said – it looks doable. Using the STM32F405 is in this case very good because it gives us juice as we want to drive a lot of sensors and do filtering options in SW later.
And yes – I know I need to make proper 3D packages for those micro JST Connectors.