SPI communication issue (software problem)

RE: SPI communication issue (software problem)

user65515 — Thu, 07 Apr 2022 01:35:12 GMT

Two issues most likely:

1. The useful Rx data from the BME280 starts with the 2nd byte, not the first; the BME280 doesn't know what to send until it receives the first byte, so the id appears in the 2nd received byte. The first byte received and reported in this case is 0x00, the 2nd byte 0x60. (Ignore this comment if you are already reporting the 2nd Rx byte)

2. The logic probe is showing ideal signals which don't match actual signals in most cases; improve performance by setting all outputs (SCK, MOSI, CS) (in CNF) to H0H1 drive strength immediately after initializing the SPI peripheral. When all is working well you can experiment by reducing drive strength but there is no real advantage to doing that.

RE: SPI communication issue (software problem)

user103731 — Wed, 06 Apr 2022 17:44:03 GMT

SDK version: nRF5_SDK_17.0.2_d674dde
I'm not sure which nRF52832 - how would I check that? SoftDevice is S132.
I did upload the logic analyzer trace, it's in the post. I don't have a trace with all of the signals together, but that one shows CLK & MISO. Here is one more that shows CLK & MOSI for the same command.

RE: SPI communication issue (software problem)

user73165 — Wed, 06 Apr 2022 13:55:22 GMT

Hi there,

Which SDK version are you using and what nRF52832 revision? Could you upload the trace from the logical analyzer?

regards

Jared