SPI Problem

[jecottrell]

I am writing some values to registers on an MCP23S17 SPI port expander and for some reason the SPI comms are causing a problem.

If I write 0b01010101, when I read the value back I get 0b10101010.
When I write 0b00001111, when I read the value back I get 0b10001111.
When I write 0b11110000, when I read the value back I get 0b11111000.


Here's my SPI setup:

[PCM programmer]

Try using CharlieU's method of defining the SPI modes, as shown
in this post:
http://www.ccsinfo.com/forum/viewtopic.php?t=26662&start=4
Instead of using "SPI_H_TO_L", use his "SPI_MODE_0_0" constant
in setup_spi().

[jecottrell]

PCM,

I remember seeing that post previously. I didn't put two and two together.

It seems to have solved the problem.

Thanks!

John