Hi, when I went from a two-board msp432 launchpad and SENSHUB stack to a four board stack, I started getting firmware I2C errors accessing the SENSHUB MPU-9150 IMU (on UCB0), but not the other sensors on the SENSHUB (also on UCB0).
The errors go away if I connect a protocol analyzer or scope probes to UCB0 I2C (via J2 pins on the SDCardReader). I have attached a scope screenshot of MPU-9150 initialization (which is working with the scope probe attached).
Any suggestions for what to look for and/or solutions would be sincerely appreciated. The scope probe is a 10:1, with 10 MOhm & 17pF input, and the board stack consists of:
/-- BOOSTXL-SENSHUB BoosterPack
|
+-- SDCardReader BoosterPack (jumpered to UCB2 instead of default UCB0)
|
+-- MSP-EXP432P401R LaunchPad
|
\-- Protoboard (has UCB1 connector only for external I2C sensor)
Thanks for any help,
Dale
