I’m trying to make a little sit-on buggy for a kid which uses the motors from 2 18v cordless drills wired up to 2 18v15 Pololu Simple High-Power Motor Controllers and controlled by a single analog joystick (Sparkfun ~10k pot). Battery is also from one of the drills, a 18v Ni-Cd.
I’ve followed the instructions in the user guide for doing the same thing with the RC channels but instead I’m using the analog potentiometer channels (as far as my very limited knowledge allows) - what i’ve got is this:
I can get each of the motors to run just fine from either of the SMCs when connected individually; mixing has been set up from input setup wizard and everything looks normal… but as soon as I connect the second controller’s signals (just the 2 analog outputs from the joystick to SMC#1 in the diagram) things go wrong:
The first SMC & motor combo still works fine -no errors and control by joystick works as before. But the newly connected controller & motor start doing strange things - at first the orange LED comes on with increasing brightness for a second or so and the motor controlled by it spins briefly before stopping… then the red error LED comes on for 3 or 4 seconds with the ‘motor stopped because required channel is invalid’ error being displayed in the control centre. It then goes off, and the motor spins again with the orange LED on, then stops with the red LED on again, and the same message displays - this keeps repeating indefinitely. In the short period when the red LED is off control of both motors via the joystick doeas appear to work.
Looking in the status tab in the control centre as this happens you can see the position of the joystick apparently moving of its own accord (even though it is not being touched), with a small signal being detected (from somewhere?) to drive the motor before the error comes on again and the cycle repeats.
I’ve tried to keep the battery & motor wires as short as possible (less than a foot from the controllers) ,routed away from the joystick wires, and they are pretty chunky and are twisted too.
Have I just wired it up wrong or is there something else obvious my novice brain doesn’t understand?!
or maybe it’s a dodgy connection on the analog signal lines? I’ve remade the splitter cable from the joystick twice as I thought this could be the problem… but still no change.
Any suggestions please?