BMA421 reads all zeros
(10-31-2020, 09:50 AM)tbondar Wrote: Hi All, I'm trying to read the BMA421 on my P8 but all I get from it on I2C is all zeros. Reading chip id gets zero, reading acceleration gets zero. I checked the SDA and SCL lines with logic analyser and they look good. Anybody seen this before?
There was an (?undocumented?) change of specification part way through the life of the P8 and the BMA421 was replaced with a much cheaper SC7A20 device that requires the step counting to be implemented in software rather than offloaded to the motion processor found in the BMA421.
Based on the comments from the wasp-os bug tracker it looks very much like the new part reads zeros for the ID:
https://github.com/daniel-thompson/wasp-...-683431763
PS Just to be 100% clear for anyone scanning this thread, this topic is not related to PineTime and the PineTime has not had any undocumented spec changes! If you have a PineTime dev kit and the sensor is not working then double check it is fully plugged in ;-), it is relatively easy to knock it out when the back is open.