Not getting accelerometer and gyro data - V1.3.2 cubesat

[W7DGP]

I am getting good payload data from the BME280 but all zeros from the MPU6050. This is apparent in Fox Telem and also from config -p:
pi@cubesatsimbeta:~/CubeSatSim $ ./config -p
CubeSatSim v1.3.2 configuration tool

Real-time output from the serial port from the Pico:

START_FLAG_OK BME280 22.70 1014.53 -10.67 36.51 MPU6050 -0.00 -0.08 -0.00 -0.00 -0.00 -0.00 GPS 0.0000 0.0000 0.00 TMP 8.07_END_FLAG

I am also getting good solar panel data. What is the best way to troubleshoot this problem?
I am planning on updating to 2.0 soon. Will this clear up the problem? I don't think this came on suddenly. I believe I never had a gyro or accelerometer reading other than zeros. At my last high school demo, I noticed it was zeros so I started up my older cubesat sim and was able to discuss satellite positioning with accelerometer data.
Thanks, Larry W7DGP

[alanbjohnston]

Hi Larry,

The testing and troubleshooting of the payload sensor data is described here: https://github.com/alanbjohnston/CubeSatSim/wiki/4.-Main-Board-2#payload-sensor-testing

Your MPU6050 data doesn't look good. If it was all zeros (0 for all six values), this would indicate that the MPU6050 wasn't detected on the I2C bus. However, some of our data is non-zero (e.g. -0.08) so this seems to suggest that the MPU6050 is there but isn't returning valid data.

If you follow the steps here https://github.com/alanbjohnston/CubeSatSim/wiki/Adding-New-Sensors to setup the Arduino IDE and install libraries, you can try installing software on your Pico that just reads the MPU6050 such as this:

https://github.com/alanbjohnston/CubeSatSim/blob/master/stempayload/GetAllData/GetAllData.ino

You can also read all about the MPU6050 here: https://howtomechatronics.com/tutorials/arduino/arduino-and-mpu6050-accelerometer-and-gyroscope-tutorial/

I suspect, however, that your MPU6050 board has failed and you will need to replace it.

Good luck!

Alan
KU2Y

[W7DGP]

Ok, ran the test you recommended:
Squelch: 1
Getting GPS data
OK BME280 21.07 1024.96 -97.07 36.58 MPU6050 -0.00 -0.00 -0.00 -0.00 -0.00 -0.00 GPS 0.0000 0.0000 0.00 TMP 6.05

The 6050 is not supplying data at all. Its a plug in board so replacing it would be easy. Also, I have a number of Arduinos that I can use to make a test fixture. I noted that this test is part of the build. Maybe I skipped over it? Anyway, its a great diagnostic.

Thank you for the helpful suggestions.
73, Larry W7DGP

[W7DGP]

I made a test fixture using an Arduino and the Adafruit example that comes with the library and it looks like the MPU6050 board is ok:

Acceleration X: -0.23, Y: -0.18, Z: 9.37 m/s^2
Rotation X: -0.05, Y: -0.03, Z: -0.02 rad/s
Temperature: 22.61 degC

I noticed the little green LED on the board was lit. This is something I can use to troubleshoot it on the cubesat. It looks like I need to pull the stack out of the frame and get things where I can see them. I'll have to do this anyway to complete the mods to 2.0.
They're not all that expensive and I ordered a new one but may not need it. There is always an upside to encountering problems like this: much learning takes place.
73, Larry W7DGP