There are certain checkup points to see if the APM is still working properly.
 
First of all, connect through Micro USB, set the correct COM port and baud rate at 115200 but don’t click Connect yet, instead go to the Terminal on Mission Planner and select the APM from the dropdown box just below flight data, then click the connect button at the right of the dropdown box.
Image
Barometer test
 

  • Type in “test” once ArduCopter v3.1.5] and press enter
  • Type in “?” and press enter after test]
  • The list of commands will appear (baro, compass, gps, ins, etc, as shown on the last picture)

Type in “baro” after test], let the test run for a while and check for any drifting on the sensor
Image
Compass and Gyro test

  • ┬áType in “test” once ArduCopter v3.1.5] and press enter
  • Type in “?” and press enter after test]
  • The list of commands will appear (baro, compass, gps, ins, etc, as shown on the last picture)

Type in “compass” after test], let the test run for a while and check for any drifting on the sensor
Image
 
Accelerometer and Gyro test

  • Type in “test” once ArduCopter v3.1.5] and press enter
  • Type in “?” and press enter after test]
  • The list of commands will appear (baro, compass, gps, ins, etc, as shown on the last picture)
  • Type in “ins” after test], let the test run for a while and check for any drifting on the sensor