Servos Not Returning to Neutral Position - RaspArm

1595294267

My servos are not moving after booting up raspberry pi.

My setup:
1.  driver board installed on v4 raspberry pi. Servo connected to first position nearest to the battery connector. Battery connected to driver board. Nothing else connected.
2.  all software installed as instructed in Manual-Adeept_RaspArm.pdf. I did the automatic setup installation but had servo problem so I also did the manual install except I did not do the "Add the RPi Car program to auto-start" section because I have a RaspArm not a car.

After powerup, the servo never moved. I tried other servos but they did not move either.

I tried the command: sudo python3 rasparm/server/server.py

Here's what my SSH session looked like:

root@raspberrypi:/home/pi# sudo python3 rasparm/server/server.py
Traceback (most recent call last):
  File "rasparm/server/server.py", line 28, in <module>
    sensor = mpu6050(0x68)
  File "/usr/local/lib/python3.7/dist-packages/mpu6050/mpu6050.py", line 60, in __init__
    self.bus.write_byte_data(self.address, self.PWR_MGMT_1, 0x00)
OSError: [Errno 121] Remote I/O error

Notes:

• The error message is always the same.
• On my first few tries, I plugged in one motor, then two, then all of them.
• I allowed 2 minutes to pass after booting up raspberry pi all while I was watching the motors.
• I tried: sudo python3 rasparm/server/server_beta.py but I got the same error no servo movement.
• I also tried normal session as 'pi' ($ prompt), and got the same results--no servo movement.
• Before plugging in the servos to the driver board, I manually turned the servos away from center to ensure that they have to seek home position when I boot raspi.
• The instructions have the user plug in the modules to the driver board after assembly. Since the error message mentions "mpu6050", I'm going to try plugging that in to the driver board to see what happens. If that works, the instructions need revision.
  

Summary:
No servo movement observed after bootup.
Tried different methods (see Notes)
Error message is consistent.
Will try again after plugging in mpu6050.

Would you kindly provide me any new information about this issue that I should consider?

Thanks.

1595294267

Well it seems I resolved the issue. The servo does move.

The fault seems to exist in the instructions manual, Manual-Adeept_RaspArm.pdf. Under the section, 3.3.Install and Remove Batteries, there's a description to install the ribbon to the batteries, then in step 2, to connect the servos, then in step 3 to debug servos. There was no advice to connect the mpu6050 to the hat.  I connected the mpu6050 and the LCD display as described under section, 3.6 Install the Pedestal near the end of the manual. Once I switched power ON, the Raspberry Pi booted, got some messages on the LCD display and the servo centered.

My suggestion to Adeept is to have a new person, who has never built an Adeept kit, build this product by following the instructions, make notes regarding problems and inaccuracies in the manual and help Adeept fix the manual, instead of having a customer like me do it for you and have a bad experience in the process of building the kit. I believe that excellent customer experience is key to long term success with a product.

1592622389

Please install LCD screen and handle before running.