Jrk 21v3 USB Motor Controller commands not recognised by DC motor

We are using Jrk 21v3 USB Motor Controller to control a 24V DC motor (Pololu - 150:1 Metal Gearmotor 37Dx73L mm 24V with 64 CPR Encoder (Helical Pinion)).
We set up the driver as suggested and connected the motor to the driver as follows:
Red motor power → OUTA
Black motor power —> GND (next to VM)
Green encoder GND —> GND
Blue encoder Vcc (3.5 – 20 V) —> 5V
The driver GUI shows that it is connected to the motor and is perceptive of the input voltage changes to the motor.

The motor keeps runs at the power from the power supply/battery (we checked using multimeter) but does not seem to receive commands from the driver. The simplest of them being ‘Stop Motor’, the motor does not do so. Every time we select 'Stop motor, the error we get is ‘Awaiting command’ and the error count increases:

We get a square wave from the encoder A and encoder B of the motor.
There is no output voltage from A (OUTA?) and B (OUTB?) pins of the driver when we select ‘Run Motor’ or ‘Stop Motor’.

Any suggestions?

The black wire from the motor should go to the OUTB pin on the Jrk (not GND).

Are you trying to do closed-loop speed control using one of the encoder signals as tachometer feedback? If so, it sounds like you are not connecting either of the encoder signals back to the Jrk. You will need to connect one of the encoder outputs to the Jrk’s FBT pin and configure it appropriately (including tuning the PID coefficients). However, before doing that, I suggest following the instructions in the “Configuring and testing the motor” section of the Jrk G2 user’s guide.

If you successfully test your motor using those instructions, you can continue to the “Setting up the feedback method”.

If you have problems (either testing your motor or setting up the feedback method), please post more details about what you are doing as well as a copy of your Jrk G2 settings file. You can save a copy of your settings file from the “File” drop-down menu of the Jrk G2 Control Center software while the controller is connected. Additionally, pictures of your setup that show all of your connections would be helpful.


Oh, that was what we were doing wrong!
Thank you, that was helpful.

We have it running now.
It is a 24V one but we probably have to run it on 12V.
Somehow, the speed is slow.
Or maybe it is just us after watching it run at 21V.

Thank you.