Second IMU error when arming Pixhawk 2.4.8 copter 4.0.1

1 1970-01-01 (601.2 KB) Hi.
After installing on pixhawk 2.4.8 copera 4.0.1 version for fmuv3 and then pixhawk 1 in 9 cases after turning on the power, the second accelerometer is initialized wrongly and “inconsistens accel” is displayed. In the log I can see that the second IMU on the ACCX, ACCy, ACCZ is of the order of 180, meanwhile the first is in the range. I will add that when the hex is armed the whole flight is ok and the values ??of the second IMU are ok. Three years ago I had a similar case with software copter 3.3.3 and the solution turned out to be soldering an additional resistor in the reset system, and in the later software it was repaired programmatically … But now I have another board. Does anyone also have such problems on copter 4.0 or 4.0.1? I do not rule out that my equipment is defective and replace the driver with a new one. In the meantime, I turned off the second IMU and the hex starts every time. In the attachment log (the moment when I touched the drone and I tested on ONESHOT using the MP tool - with no effect - rcout signal at 5 and 50% 1050i1500)


I have the same problem with a 3DR Pixhawk. When the temperature is very low. I experience more problems

I found an old article based on which several years ago I caused pixhawk 2.4.8 to start every time even at -15 degrees C.
Later software correctly reset the second IMU.
I noticed that in copter 4.0 appears when starting EK2 IMU1 forced reset. In version 3.6.12, even at low temperatures I had no problems on this equipment with the second ACC.

Hey, I found a solution. Instead of soldering a resistor on a capacitor blocking 3.3v LSM303D power supply to discharge the voltage after turning off the power I plugged the 220 Ohm resistor into the ADC3,3V socket. In pixhawk 2.4.8 the LSM303D power supply and the 3.3v pin are connected and this works. I do not know if it will work on pixhawk produced by 3DR where there is a more sophisticated power distribution. In my case, the second IMU resets correctly and I did not have to solder …