SPI communication is unreliable

[Jamie]

Hi,

I am using the SPI ports (0 or 1) to communicate with a peripheral chip, and the operation is undeterministic.

For test, I put the SPI code to read the peripheral family ID in a loop, where if the read is correct I light an LED, and if the read is not correct I do a NRF_SystemReset(). Upon execution, the LED takes an undeterministic amount of time to light, from 1-10 seconds on average. I test this code using the Nordic Eval-10001 + breadboard, and my own custom hardware with peripheral--both operate the same. Using the same peripheral from the breadboard and another Cortex-M0 (LPC1114), the operation is perfect and deterministic every time.

What could I be doing wrong, or, what could I supply to help ease the solving of my problem?

Thanks, Jamie

[Håkon Alseth]

A picture of the test setup would also be nice to see. Long wires and breadboards, in combination with high SPI frequency, tend to give a higher bit-error-rate.