Hi everyone, I’m using GRBL 1.1h on an Arduino Uno with a CNC Shield v3. My setup includes:
3 motors:
X-axis connected to X driver
Y-axis split across two motors: one connected to Y, the other to A
Laser connected to PWM pin D11
The issue I’m facing is that the laser turns on during homing and when jogging the axes manually. It only turns off when the machine reaches the home position or stops moving. I’ve already enabled laser mode using: $32=1. But even before running any G-code, the laser activates during homing or jogging. Even when I disconnect the PWM wire from the laser module, the laser still turns on during axis movement.
Has anyone experienced this? Is there a way to prevent the laser from firing during non-engraving moves?
That’s definitely interesting - could you share a photo of the wiring to your CNC shield?
Also, if you could provide us with your user bundle (essentially a portable backup of all your settings), we could take a closer look. User Bundles - LightBurn Documentation
You have a lot of flying connections there, and twiseted copper wires that should not touch. I’d recommend cleaning the wiring first. It might be already caused by the wiring that noise is creating enough interference to turn on the laser.
This is not a settings issue, this is an electrical issue.
I can’t tell from the pictures, but do you power the laser head from a different power supply? If so, the GND wires of both power supplies need to be connected to create a common ground.
Additionally, a floating signal wire (not connected to the common ground level will cause this behavior on laser modules, it’s the same like not connecting it at all, this will also cause flickering with most modules.
@misken said it best, fix that wiring. If you do not know how, Google it.
@MikeyH says Those images tell us little because the board labeling cannot be seen. Without wire markings, there is no way we can tell if any wires are crossed.
I saw a few tutorials suggesting to connect the PWM signal on this “Z+” connector, so I won’t blame you for that.
Do you have a multimeter with continuity mode? See whether pin D11 from the Arduino goes to the “SpnEn” pin on the CNC Shield instead..
If I counted right, it’s this pin here (check with the label on the Arduino board):
