Pidog's servo not works

Robotic kit for Raspberry Pi
1

Hello,

I received the pidog and assembled it recently. After the work it is done, I found the around 6 Servo don’t work. They are at positions: 2, 5, 7, 8, head pitch and head yaw. I switched the pins and didn’t get any luck.

Could you send me the replacement? Thanks

2

Have you tried replacing the non-working servo with a working servo on the PWM pin interface to verify it?
How did you determine that the servo is not working?
I recommend providing the steps you have taken to verify the issue.
If you can provide a video, that would be helpful for us to analyze and troubleshoot the problem.
If the video file is too large, please upload the recorded video to OneDrive, share the video link with us, and give us access permissions.

3

Thanks for your reply. Please see inline:

Have you tried replacing the non-working servo with a working servo on the PWM pin interface to verify it?

Yes, tried

How did you determine that the servo is not working?

Besides switching with other servos, I ran the below test code:

  1. sudo python3 servo_zeroing.py
  2. sudo python3 0_calibration.py

and other examples under ~/pidog/examples.

The servo didn’t move.

I took the videos from both sides of the pidog when the 0_calibration.py. Thank you

4

We will send you the replacement servos.
Please contact us at service@sunfounder.com

Note:
Before assembling the servos, make sure to power on the PiDog and run the following commands:

cd ~/pidog/example
sudo python3 servo_zeroing.py

Then, connect each servo to the PWM pins for zeroing. (To ensure the servo is correctly set to 0°, first insert the servo arm into the servo shaft, then gently rotate the arm to different angles. This servo arm is just to help you see that the servo is rotating.)

Please refer to the tutorial link:7. Servo Adjust(Important) — SunFounder PiDog Kit 1.0 documentation

Servo Adjustment Tutorial
After completing the servo zeroing assembly, proceed to do the servo calibration:
Calibration Tutorial

cd ~/pidog/examples
sudo python3 0_calibration.py

It is also recommended to watch our assembly videos to confirm the assembly process is correct:

Assembly Video 1
Assembly Video 2

5

I did it when assembling. Thank you very much! Will contact support.

7

Is the behavior identical when supplied by external power instead of just the battery?

8

If you do not connect the battery to power the Robot HAT and only provide external power to the Raspberry Pi, the servos and sensor modules connected to the Robot HAT will not work. This is because the Raspberry Pi cannot power the Robot HAT. If you connect the battery to the Robot HAT, it will receive power, and at the same time, the Raspberry Pi will also be powered. Therefore, when you connect the battery, there is no need to provide separate external power to the Raspberry Pi.

9

Sorry . I meant to say external power as well as the battery. I was suggesting that the battery voltage may be low, as I could not see any usb power on the video. Apologies for any confusion.

10

New servos work well, no problems with the shaking servos. thanks

11

if it’s a low battery situation, the servo will only fail to stand or not fully stand, and the raspberry pi will shut down.
It won’t happen like in the video. Unless the return to zero adjustment wasn’t done properly, or the servo is faulty and the gears are stuck and spinning around.

12

Thank you for spending the time to clarify. Much appreciated.