Raspberry pi expansion system page
If you want to hook up your raspberry pi to interface with the rest of the world, this is the right place to look!
The rpi_serial board is the simplest breakout board for the Raspberry pi.
It breaks out the following serial buses:
As the rasberrypi runs at 3.3V IO signal levels, the board allows 5V peripherals to be connected. The board can be configured for 5V operation or for 3.3V operation but not both.
Planned are the optocoupler expansion board and the button expansion board. If you have suggestions for more, please let us know.
These expansion boards have two SPI connectors. The first SPI connector is for data transfer during normal operation. The other can be used to daisy-chain the SPI bus to other SPI expansion boards. Or it can be configured to be used as the programming port for the onboard AVR chip.
It should be possible to use one of the raspberry pi SPI buses for data-transfer, while you use the other one to program the AVR chip on the expansion board.