Can't slow down SPI clock speed

Official Hardware MKR Family MKR WiFi 1010
1

I am trying to slow the SPI clock speed way down. It seems like nothing I try changes the clock speed on my scope. This should result in a much slower than measured speed of 10 MHz.

SPI.beginTransaction(SPISettings(125000, MSBFIRST, SPI_MODE0));
SPI.setClockDivider(128);

Is SPI speed locked on these devices because of the WIFI communications?

2

I think you're using this incorrectly. As described here, try

SPI.setClockDivider(SPI_CLOCK_DIV128);

Note that from here, we have

#define SPI_CLOCK_DIV128 0x03
3

Thanks for the response. I was using this #define earlier. I guess with all of my trying of different things I left the wrong value in there. I will go back to this and test again.

4

Using:

SPI.beginTransaction(SPISettings(125000, MSBFIRST, SPI_MODE0));
SPI.setClockDivider(SPI_CLOCK_DIV128);

My measured SPI clock pulse width is about 100 ns. I am assuming a higher clock divider should result in slower clock. I have also tried different max speed settings from 10MHz down to 125 KHz. Again, nothing seems to change the SPI clock speed.

5

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