Spring 2016 3DOT Goliath,Troubleshooting the 3Dot Board

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By:  Tae Min Lee (Systems)

After finishing the assembly of the 3Dot Board with our mentor Nick and Lawrence at AOSA we had to troubleshoot if we had any bad connections.  These are some of the procedures Nick and the group came up with to test the 3Dot Boards by following the procedures shown below:

Test Procedure:

  1. Take out the battery before testing using a multi meter
  2. Set the multi meter to measure resistance setting in the 100k ohm range
    1. Check for shorts on the Dual Motor Driver Chip
    2. The measured impedance of any two pins should be much higher than the 100k ohm.
    3. If a value of 0 resistance or close is displayed than you have a short
  3. Check H-Bridges are bridged based on the schematic (figure 1)
    1. Checked A01, A02, B02, B01
  4. Upload a simple code to test the motors (figure 2)
    1. Measured the voltage across the motor terminals to make sure the correct voltage was outputted

circuit 1

 

 

 

 

code

 

 

Conclusion:

No shorts were found on the 3Dot Board and the H-Bridge connections were connected.  However, we encountered a problem when we tested the motor code only Motor A was operating at the time.  Motor B on the other hand was not operating and the measured voltage across the motor B terminal was zero.  We had Nick perform additional test on the 3Dot board and from his analysis the possible problems were either the Dual Motor Driver or the Atmel Chip being damaged during assembly or other causes (ex. shipment, electro static, heat, etc.).

3DOT

 

References: 

1- https://www.pololu.com/product/713

2-http://forum.arduino.cc/index.php?topic=214730.0