I'm noticing some irregularity on the SCL line coming from my Nordic 52832. I've attached a Saleae logic trace here. What are the potential causes for this type of behavior?
I'm noticing some irregularity on the SCL line coming from my Nordic 52832. I've attached a Saleae logic trace here. What are the potential causes for this type of behavior?
We suspect that the pullups are too weak. We have answered the duplicate question in MyPage(case id 40611).
Answer from MyPage:
I was looking at the TWI trace data, and it looks like the pull-ups on the SCL and SDA lines are too weak for 400 kHz. Are you using the internal pull-resistors? These will limit the frequency greatly, and we recommend that you use external pull-up resistors in the range of 2.2k to 3.9k in order to use 400 kHz mode. For the 100kHz mode, the internal pull-ups (nom. 13k) will work without issues.