Installing a Raspberry Pi Kit
How to attach a Raspberry Pi Kit
The Open Access v4 comes equipped with a 6-pin header that can directly interface to any Rapsberry Pi computer.
Additionally, mounting holes are provided for attaching the device directly to the Open Access board, making this a clean, compact solution.
Header location and pinout
The header is located on the lower left corner of the PCB, next to the Lithium 2032 battery. It is labelled J5/RPi-IN.
Pinouts are as follows:
1 3.3V In
2 +5V Out
3 GND
4 UART RX
5 UART TX
6 Spare
Schematic:
Raspberry Pi Pinout and connections
The supplied ribbon cable will power the Raspberry Pi, and optionally allow a direct UART interface to between the Open Access and the Pi, saving a USB port. When used in this manner, 2-wya communication is possible, but not software updates. Updating the software on the Open Access requires attaching a USB cable and setting jumper J5 to "USB." Set J5 to RPi to use the on-board UART connection.
Note that the Mode B and Model B+ have different connectors. The older Model B uses a 26-pin 2-row connector, while the newer B+ uses a 40-pin connector. Fortunately, the power, ground and UART pins are in the same place for each. When installing the Raspberry Pi connector, make sure to connect Pin 1 on the Open Access with Pin 1 on the Pi. For reference, here is the RPi GPIO pinout:
Mounting the Pi
- A Rasberry Pi Model B mounts straight to the PCB using the mounting holes at opposite corners of the PCB. 0.750"nylcon spacers and 4-40 nylon screws are provided.
- A Model B+ uses different hardware. The straight spacer goes on the lower left mounting hole, and the offset spacer goes on the upper right.
