This illustrate the Raspberry PI connectivity board. The PSU on top can be switched on/off so we can reboot RPI. The actual RPI will connect using a 40 pin Connector. I am not sure about the mechanics yet, but I am considering mounting it so it’s Ethernet and USB sticks out in front. The adapter board will as far as RPI goes be a Hat using Smart SPI. Basically a Hat with a 40 pin for backbone + the standard PI 40 pin. This Hat should have fixed address 0 and optionally be able to use a higher speed on the SPI.
Expected usage of this is that we use this for cryptic internet access, to provide web servers, complex HMI or simply heavy math. A M4 is fast, but it is no comparison with it’s a Quad 64-bit 1Ghz bigger ARM Brother. I am also considering phone and Speech services that require this grade of Computing Power. It is a lot of Things that is much easier to do on a PI than on an embedded computer.