Incorrect values during SPI communication with the MAX30003 with your own microcontroller can often be traced to signal integrity issues or incorrect configuration. Here are the recommended troubleshooting steps:
Check SPI Configuration:
- Ensure the SPI mode matches the MAX30003 documentation, i.e. it is set to CPOL = 0 and CPHA = 0, or CPOL = 1 and CPHA = 1.
- Confirm that the CS pin goes low just before the SPI transaction and returns high immediately after.
Inspect Physical Connections:
- Verify that the MISO/SDO pin is properly connected and not experiencing glitches.
- Double-check all cable and jumper connections for secure and correct placement. Test with different jumper cables to eliminate potential cable faults.
Perform Diagnostic Register Reads:
- Read the STATUS register.
- Read the INFO register. These reads can help confirm whether the device is responding correctly.
Reset and Reconnect:
- Try reconnecting the board to the MCU setup and rerun your code.
- If the issue persists, swap the board with another one to rule out hardware faults.
Following these steps should help isolate and resolve the issue.