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SPI.format(bits, mode) not working as advertised

Topic last updated 02 Jan 2018, by Jon Freeman. 3 replies
Jon Freeman
29 Dec 2017

Board is Nucleo F401RE. Using any number for bits in SPI.format(bits, mode) results in 8 bit SPI, all except for 16, which results in 32 bit SPI. Seen on the 'scope, the 32 bits appear as two groups of 16 with a slightly longer clock low interval (approx 2us) after the 16th clock _-_

Wim Huiskamp
29 Dec 2017

This issue has been addressed several times before. See for example here. Search mbed site for nucleo and SPI to find more info. The ST devices seem to support only 8 bit multiples. You should also update the mbed libs before testing again.

Wim Huiskamp
29 Dec 2017

This issue has been addressed several times before. See for example here. Search mbed site for nucleo and SPI to find more info. The ST devices seem to support only 8 bit multiples. You should also update the mbed libs before testing again.

Jon Freeman
30 Dec 2017

Thanks Wim, Updated library through 156 to 157 and the problem persists. I can work-around so no problem, but it seems this has been around for a year or more now.