Servos broken on PiDog 2, Robot Hat+ 5, Raspberry Pi Zero 2w

Help. My Pidog is unable to move. It can play sounds and have video, but no servos turn at ALL. not a single twitch. the LED lights at the front isnt working either.

tell me if u need more photos. I ran the i2cdetect thing and it had like nothing on bus 1

If you connect an external power supply to the Raspberry Pi, the Pi can still boot up, play sounds, and capture video. However, the servos, LED strip, and other sensors require power from the Robot HAT to function.

Could you please check whether the power switch on the Robot HAT is turned to ON, and whether the power indicator LEDs are lit? If the LEDs are not on, you can try charging the Robot HAT by connecting an external Type-C power supply to it.

Additionally, if you press the ZERO button, all servos on the PiDog should go through a calibration cycle, and the PiDog should end up in a lying-down posture.

If the issue still persists after trying the above, please take a short video or a photo showing the Robot HAT’s power switch in the ON position and send it to us for further analysis.

If i press the zero button, every servo moves and locks

when does the mod come

When you were assembling the robot, did you perform the steps while the Robot HAT was powered on? In other words, did you strictly follow step 11 of the assembly manual, and then proceed with steps 20, 22, 25, 27, etc., without disconnecting the power?

You mentioned: “If I press the zero button, every servo moves and locks” — this actually sounds like normal behavior. If the servos are at the correct angle at that moment, then the PiDog should be ready to execute movement commands properly.

I’d like to check the posture of your robot dog after pressing the ZERO button while it’s powered on. Could you place it on a table and observe whether its legs are in the correct position? If the angles are off at this point, it may cause the robot to get stuck or move incorrectly.

i think i assembled the legs at the wrong angle since the zero button has some really lopsided legs, but i dont think it solves the main problem of the servos not moving. even if i run the calirbation script, it doesnt lock or move.

Regarding the incorrect initial angle of the servo during leg assembly, please follow the steps below to return the servo to zero and assemble it:

1.Power on the robot hat5.

2.Briefly press the zero button.

3.Connect the servo cable to the PWM pin. At this point, you will see the servo return to the zero position.

4.Do not unplug the servo that has been zeroed yet. First, follow the assembly steps to fix and assemble the servo, then disconnect the zeroed servo.

5.Repeat steps 3 and 4 to zero and assemble the remaining servos one by one.

The zeroing and assembly procedure is the same for all 12 servos. After completing the full assembly of PiDog, proceed to run the calibration example to calibrate the servos.

Regarding the issue of no servo movement when running the calibration script? (Neither locked nor moving)

After running the calibration code to calibrate a specific servo, do all servos fail to respond? Or is it just a particular servo? All servos moved and locked normally during zeroing, correct?

If the calibration script fails to trigger a servo response, it is likely due to a hardware fit issue caused by assembly deviation or an underlying connection/command issue when running the script.

Check whether the I2C port is enabled. Run the calibration script using the correct command:
sudo python3 0_calibration.py

If there is still no response, check each servo cable connection one by one for looseness.

i2c port is on, when i run the code, it opens up an interface but if i press the up and down arrows or what the key is, it displays a angle change but doesnt really move. all servos fail to respond. i think all the servo cables are correct. i asked chatgpt, it said it is prolly the 40 pin GPIO header’s connection issue, but i dont really know. is it possible for me to switch out my HAT and PI?

Please provide clear photos of the Zero 2W and the Robot HAT. This will help us check whether there is an issue with the 40-pin GPIO interface on either board, or a connection problem between them.

It is very possible that the GPIO pins on the Zero 2W have not been properly soldered, or that the GPIO female header on the Robot HAT has not been properly soldered. This could prevent the Zero 2W and Robot HAT from connecting properly. As a result, when you run the calibration example, the commands sent by the Zero 2W are not received by the Robot HAT, and the servos do not respond.

Regarding the servo returning to zero: this function is programmed directly into the Robot HAT. It does not require the Zero 2W to execute. Even without the Zero 2W connected, the servos can return to zero through the Robot HAT alone.

tell me if you need more pictures

Please contact service@sunfounder.com with your order information and shipping address. We will send you a replacement Robot HAT.

Once you receive the new Robot HAT, please test it using the command i2cdetect -y 1.

Please copy and send us the output at that time.