Brickpi3 - Can't power up dv3 motors


#1

Hi dexter forums,

I can’t for the life of me get a dv3 motor connected to the MA port moving.

Here are some relevant outputs from the example programs:

! have connectivity
pi@dex:~/Dexter/BrickPi3/Software/Python/Examples $ sudo python Test_Connected.py
BrickPi3 connected and running

! have connectivity
pi@dex:~/Dexter/BrickPi3/Software/Python/Examples $ sudo python Read_Info.py
Manufacturer    :  Dexter Industries
Board           :  BrickPi3
Serial Number   :  98075D12514D32384E202020FF111E3D
Hardware version:  3.2.1
Firmware version:  1.4.6
Battery voltage :  12.223
9v voltage      :  9.106
5v voltage      :  5.164
3.3v voltage    :  3.322

! enough power
pi@dex:~/Dexter/BrickPi3/Software/Python/Examples $ sudo python Read_Voltages.py
Battery voltage: 12.219  9v voltage:  9.087  5v voltage:  5.168  3.3v voltage:  3.321
Battery voltage: 12.230  9v voltage:  9.095  5v voltage:  5.171  3.3v voltage:  3.320
Battery voltage: 12.223  9v voltage:  9.087  5v voltage:  5.182  3.3v voltage:  3.319

! doesn't seem to detect the dv3 motor in port MA.
pi@dex:~/Dexter/BrickPi3/Software/Python/Examples $ sudo python LEGO-Motor_Status.py
[0, -128, 0, 0]
[0, -128, 0, 0]
[0, -128, 0, 0]
[0, -128, 0, 0]
[0, -128, 0, 0]

Any tips?

Cheers,

Jason


#3

Hi guys,

Just wondering if anyone has any feedback for this particular issue?


#4

Any ideas i can try to get these motors working?


#5

It seems to be working just fine, based on the output you posted. Check out the get_motor_status documentation here. Of the four values returned, the first 0 indicates that no flag bits are set (a good thing), the -128 means the motor is floating (no power or passive braking is applied to the motor), the third value indicates motor encoder position (0 means no rotation has occurred), and the fourth value indicates the current speed of the motor in degrees per second (0 means the motor isn’t turning).

When running the LEGO-Motor_Status.py example program with the motor connected to motor port A, try rotating the motor by hand to see the encoder value and current speed value change.