Current reading is OK, but wrong value display in MissionPlanner:
Since MP do display a current flow, we can assume that the current flow direction of the sensor as well as the wiring of the sensor, BEC to FC is OK. So, let us find out if we have here a hardware or software issue.
What do you need for the test ?
- Current source. Best would be a bench top power supply which is at least able to supply a current of 5A. Better 10-20A. We use 50A during the final test QC.
- Digital voltmeter.
- The final test result paper, which comes with every sensor board (for example with an A/V of 60.91846)
- Of cause, your setup with MP running and connected to the FC.
Let the current flow trough the sensor and measure the voltage on the yellow wire at the FC power port.
Record down the value of the current and the voltage measured with the digital voltmeter.
For example, the current is 15.6A and the measured voltage 0.261V.
1V / 60.91846A/V = 0.01641539V per Ampere.
0.261V / 0.01641539 = 15.899A
Measured current = 15.6A
Calculated current = 15.899A
Difference = 0.299A
Above calculation would show, that the sensor is OK, which means the wrong displayed current in MP is either firmware or parameter setup issue.
The outcome of above test is very much depend on how accurate you can validate the exact current flow though the sensor, as well as the DC measurement error of your digital voltmeter.
If you change parameters in MP, then please ensure to save the changes. If the error does not disappear, then please reboot FC and MP.
If you use any versions of the “THE CUBE” flight controllers, then please let it heat up to operation temperature and reboot before you perform the test.