Raspberry Pi High-Precision AD/DA - SPI & GPIO question

Related to this topic.

The manual on page 7, interface definition, indicates that gpio pins 31, 33, 35, and 37 are used to “extend to sensor interface” .
What does that mean?
Doesn’t it use the SPI bus for data transfer?

Hi @sgw!

Welcome to the RobotShop community!

If you have a look at the documentation for the RB-Wav-08 and check out the schematic PDF you’ll notice that pins 31,33,35,37 seem to be named P22-25. It seems the board simply breaks those out to those yellow male headers (H7).


They do not seem to be connected anywhere else on the PCB (according to the schematic, at least). In the manual on page 2 the manufacturer refers to those yellow connectors as:

So I figure they are used for compatibility with other RB-Wav boards. Pins 31/33/35/37 are probably used to control those other possible boards.

I hope this helps!


P.-S.: I’ve moved your question to its own topic since it is a different question than the OP, not a new answer to it.