Donkey Car no longer responding to throttle

#1

I’ve assembled the Donkey Car (using the Jetson Nano instead of RPi). I’ve also replaced the NiMH battery with a LiPo. I performed the calibration procedure, calibrating both the steering and the throttle, which had worked initially with the ESC beeping in response to the 370 value entered into the calibration line. I added the maximum, zero, and reverse throttle values to the myconfig.py, and had test driven the Donkey Car using the web browser controller. I originally had trouble with the camera not being recognized by the Nano, but was able to resolve this with further changes to the myconfig.py file. The test drive worked for a few minutes, but then stopped responding to any throttle value, but steering still worked. The ESC red LED was blinking.

What I’ve tried:
-I noticed that the ESC had the jumper set to NiMH instead of LiPo, and I switched the jumper to LiPo.
-I changed the ESC control wires on the I2C board from Channel 0 to the Servo Steering Channel 1 to see if they respond to the signal from Channel 1
-I reconnected the ESC to the RC receiver and tried the throttle trigger, and the ESC/Motors responded to the trigger with both forward and reverse on the trigger.
-Run donkey calibration again on the throttle channel to test calibration again. This time, setting PWM value to 370 did not produce a beep from the ESC, and I then tried several different integer values from 0 to 1500, but again no response from the motor.

I’m afraid I am out of ideas regarding how to further troubleshoot this issue. Any help would be appreciated.

1 Like
#2

You should try Slack for some answers. You will probably get feedback faster. (I wish I could help, but I am a new to Donkeycar).

#3

what lithium battery did you use? 7.4V I hope.

Sounds like the lithium battery voltage is way too low. you must have an alarm connected to the balance plug of the battery when in use so you don’t discharge any cell below 3.0 V. Once you do that, you have damaged the battery and it will not have the same capacity as new. You also will want to watch your charge currents( you must have a special charger which allows adjusting charge voltage and currents ).

Lithium batteries are a whole bag of worm in itself so when you go down that path you MUST be ready to do everything necessary to be safe and operate the batteries in ways to keep them safe and lasting a long time.

#4

I also meet with the same problem ? and get into trouble.

#5

Another problem can be not having the center position for the ESC properly set. And it can take many iterations of small changes to get the correct zero position.