Need help with new JRK 12V12

Hi all,
I’m new with this product. I use it to control motor as steering and using RC input.
After I configured the JRK as told, I got it work. But there are 2 problems:
There is a 5v out put to motor and make motor keep runing when remote control steering at center. How can I set it to 0V?
When steering knob set to left, I got 12V (VIN is 12V). When steering set to right, I got -5V (Should be -12V). How can I fix this.
Other question: How can you set it up to make motor return to center when steering knob return to center?
Please help. Thanks


Both of your problems sound like a result of not having the RC input scaling configured properly. You can calibrate the RC input by using the “Learn…” button on the Input tab of the Jrk Configuration Utility, or by manually setting the scaling parameters; for more information, please see section 3.b of the Jrk user’s guide. (In general, you should read through all of the user’s guide to familiarize yourself with what the Jrk can do and how to work with it.)

- Kevin

Thanks Kevin
The problems have been solved.
Anyone know how to make motor return to center when steering knob at neutral? Thanks in advance


What are you using for position feedback?

- Ben

Currently I don’t use feedback

Your desired behavior requires positional feedback; the jrk cannot make the motor go to a particular position without knowing the actual position of the motor.

- Ben

What is your sugestion for positional feedback? (potentiometer, servo?)
If I use a potentiometer. There are 3 connection and I don’t know which one is which that connect to JRK (not an expert)
Would you please show me more detail. Thanks

Using a potentiometer would be the best way to get positional feedback. To connect it, the wiper should connect to the feedback input (FB) of the Jrk, and the two ends of the potentiometer should go to 5 V and GND. Unfortunately, we do not have a wiring example for the Jrk specifically, but you might find some of the documentation on connecting potentiometers to a Maestro and a Simple Motor Controller helpful (those examples show how to connect a potentiometer to use for input instead of feedback, but the idea is the same).

- Kevin

If I use a potentiometer, will the motor return to center when steering knob does?

Yes, if you configure things properly, the steering knob will correspond to motor position.

- Ben

There are 3 pins on POT. Pin labeled #3 is in middle. Which wire should connect to which pin? Please help. Thanks

Is there anyone could give me some help please? My Potentiometer got 3 contact labeled 1,2,3. Contact labeled #3 is in the middle. Is that contact the feedback out put? Thanks for any kind of help

Do you have any information on the potentiometer, such as a datasheet, that might tell you what the pins are? If not, you should still be able to determine what they are by measuring the resistance between different pairs of pins while you turn it. Once you find a pair of pins between which the resistance does not change when you turn the pot, you will know that those two pins are the end terminals, and the third one will be the wiper terminal.

- Kevin

Hi Staff
I have connected my JRK 12V12 with my RC system using potentiometer set up. It works well with feedback disable. When I configed FB selected Analog voltage the motor didn’t turn. I connected the 2 end of potentiometer to 5v and ground and the wiper connected to AUX or either FB (the motor didn’t run either one). What am I missing here? Please help.

Hello. We have a FAQ entitled “Why is the jrk not driving my motor?” which should help you:


Thanks guys for all of your help. Finally, I got it works correctly as I want so far. I’m using single motor ESC for dual motors and it works just fine but the speed kinda slow. I upgraded the ESC to dual motor output but as long I plug it in receiver the JRK give a “motor driver error” message.
And what I have found:
The working single ESC output to receiver is 5.28v
The new dual ESC output to receiver is 5.78v (.5v difference)
If that the reason that I got the JRK error or something else? And how would I correct it? Please help

Note: I have tested the dual ESC with regular servo on CH1 and it works fine that meant not a defective ESC.
Thanks once again guys for great product and support

Hello again.

Could you please explain how everything in your system is connected?

The jrk 12v12 motor driver error should only happen if the motor driver detects that motor output A is shorted to GND or VIN, which should not be the case if your motor is connected properly and is a reasonable size. Do you know any specs for the motor that is connected to the jrk 12v12, such as the stall current?

I don’t know what’s causing the error, but maybe jrk can recover from it and that might be good enough for you. What error response options have you configured in the Errors tab of the jrk configuration utility? The default behavior is to try to recover from Motor Driver Errors, but if you have set that error to “Enabled & Latched” then it requires user intervention or a serial/USB command to clear the error. Try setting that error to “Enabled” instead and see if that improves things.


I use JRK for RC system. Powered by 12v batt that connect to RC dual motor ESC input. From ESC output connect to receiver CH2 to power the receiver. From receiver CH1 connect to JRK using pulse signal. On JRK powered by 12v batt (same source that powered the ESC). Output to a windshield wiper motor using 12v as well. Motor geared up to a POT for feedback.
I have no spec on the wiper motor.
I set “Enable” on error tab. Hitting clear error and no response

It works fine with my old single motor ESC. Used same setting with the new dual motor ESC red led on error 0x0004 as long I plug in the receiver

There one point I mentioned that the old ESC output to receiver on CH2 is 5.28v give CH1 5.28v. I have 2 single motor ESC measured the same. I think this 5.28v from CH1 that use to power JRK? The new ESC is measured 5.78v give CH1 5.78v. And it higher than normal voltage to the JRK pulse signal V input that why give an error?

I have tried to use 2 receivers .One for ESC connect to CH2, one connect to JRK on CH1 for steering. There is no error but since the receiver that connect to JRK got no power supply on CH2 then it draw 5.30v out from JRK and give only 6.30v to output to motor. My wiper motor using 12v so still didn’t work. I tried 6v motor it works.

I don’t know my explaination that help you understand my set up, if you don’t understand any point I would to explain more

So it sounds like you are powering the RC receiver from a 5 V output on your dual ESC. You also connected the RC receiver to your jrk. How many wires run between the RC receiver and the jrk? For each wire, please tell me what pin it connects to on the receiver and what pin it connects to on the jrk.


"So it sounds like you are powering the RC receiver from a 5 V output on your dual ESC"
That’s correct. 5v output from dual ESC connect to CH2 on RC receiver. Also at CH1 terminal on receiver got 5v as well( I checked with multiple ESCs and receivers )

I connect From CH1 on RC receiver to pulse signal input on JRK

There are 3 wires from RC receiver to JRK colored: white=RX, Red=positive, black=negative
White connect RX from receiver to RX on JRK
Red connect + from receiver to 5v (out) on JRK
Black connect - from receiver to GND on JRK
All 3 wires did not short to each other (checked)