We have been encountering an issue with UART1 on the IMU300ZI. On the dev kit, we have had no issues with it working correctly, however, when we moved the IMU on to a custom board, we could not read in gps packets, whether they be NMEA or UBLOX packets. After a lot of headaches, we found that the UART wasn't detecting any data on the line, and switching to using the debug UART worked. To clarify, we jumpered UART1 RX to UART2 RX and changed the code in the below screenshot. this issue has lasted through several board revisions, and we have not been able to figure out why it happens. Any insight into this issue would be greatly appreciated.
IMU300ZI UART1
Pin 7 of IMU300ZI is SPI/UART Interface selector, could you please check you have selected UART by pin 7 already on your customer board?
Reference: https://openimu.readthedocs.io/en/latest/300ZI/pinout.html