I'm successfully using nRF52832 on custom designed PCBs. I've been trying I2C communication (nRF is the Master) using the TWIM driver. This has worked successfully at 100kHz, 250kHz and 400kHz.
I wish to increase the communications speed as much as possible (the slave device is capable of 1000kHz clock speed). I've experimented with changing the FREQUENCY register:
There doesn't seem to be an exact mapping between the register value and the achieved SCL frequency, but I was able to get SCL @ ~800kHz by programming the above register to 0x0C380D40 = 205000000 (decimal).
To get this high speed I also had to set the GPIO configuration to "high drive strength" for both "0" and "1" signals.
I'd like to know if anyone else has experimented with this, and any problems they encountered. Am I likely to encounter problems with Nordic SDK drivers because of running at "out of spec" SCL frequency? Is this going to have huge impact on power requirements?
Thanks for any information!