The prototype for my Propeller accessory is pretty much finished now. The final one will be a proper PCB with hopefully FOUR Propeller chips on it! I'm using one for this prototype to ensure that the basics are working such as I2C and bidirectional serial comms between the Pi and the Prop.
The Prop Plug is only temporary and allows me to get an extra debug channel into the top board while debugging code running on the Pi.
This board has 24 GPI pins available to the user. The final build might have as many as 64!
Next I'll be adding the code that lets me talk to the Prop over the Pi's GPIO pins using Serial. I'll need to find way to drive an extra pin to bring the Prop out of reset at the right time during comms.
Then, after that I'll be hooking up the DS1077 chip (with 3v3 / 5v level shifters) and making the Propeller dynamically change it's clock speed!