Pulsing on Idle (BasicESC with T200s)

Got the two T200s on our raft and in the water the other day, just having it run through a program (go forward for a few seconds, stop, turn, go forward, turn again, blah blah blah) and it worked beautifully! Each T200 is running through a BasicESC. Really impressed with the power of these things. However, once I introduce remote control to the project, I run into an issue.

I am using a two HC-12 433 MHz serial communication modules to communicate between the custom controller and the raft. I can send the commands just fine to make the thrusters do what I want, but when the joysticks are centered, meaning the ESCs should be receiving the stop command (“servo.writeMicroseconds(1500)”), both thrusters pulse up to what appears to be full throttle and then back down to stop, over and over, just pulsing off and on.

This only happens once the HC-12 is connected. If unplugged, it stops pulsing. Not sure what is happening here or if anyone has experienced anything like this, but I would love any help you guys might have to offer. This is for a senior capstone project and we’re supposed to be demoing the remote control part of it to our professor tomorrow. I’ve gone over the code countless times and can’t find anything wrong there. Not finding any loose wiring. Just figure that somehow the wireless communication is affecting the PWM on the ESCs.

Hello,

I have seem 433MHz communication causing interference in PWM signals before. Try twisting the signal wires, and add ferrite rings to the signal wires if you can.
You can also try attaching an oscilloscope, but I’m afraid you may be unable to see the interference due to the much higher frequency.