Using a momentary switch with JRK 24v21


I am using the JRK 24v21 to control brushed DC motor with a RC input remote to control the motor speed. I also want to use a momentary switch which just turns the motor on and off, anytime I press it. As the motor turns on, I would ideally like to stay at speed 0 and then I can use the RC remote to increase the speed. What is the best way to achieve this? I do not want to ideally add any other board in the circuit. Is this possible to do with just the jrk and an external switch?


Hello, Tanmay.

I moved your post to the “Motor controller/driver and motors” section of the forum since it is more appropriate.

It sounds like the RC control you are describing is the normal open-loop speed control mode described in the “Setting up RC control” section of the Jrk G2 user’s guide (i.e. RC input with no feedback). As far as stopping the motor with a momentary switch, you might be able to get the behavior you want by connecting your switch to the Jrk G2’s RST pin. Alternatively, if you use a normally-closed switch, you could probably have your RC signal connect through the switch; that way, when the switch is opened it will result in an “input invalid” error. This also allows gives you the option to have the error latch or enable a “hard stop” (which ignores deceleration limits when responding to the error). You can find more information about this in the “Error handling” section of the same user’s guide.

It sounds like you want the motor to stay at rest after the switch is turned back on. Since the Jrk G2 does not have a safe-start feature, if your RC input is telling it to go at a non-zero speed, it will just go at that speed after the errors have been cleared. If you use an RC stick with a spring return to move it back to the neutral position, that might work for you. Alternatively, you might consider switching to one of our G2 Simple Motor Controllers, which offer a safe-start feature. However, note that it would require you to put the stick in the neutral position before letting the motor start up again.