I'm currently building a CNC using an Arduino Uno and CNC shield with DRV8825 drivers. I added a capacitor board to join the 3 axis limit switches with the negative side of the capacitors going to the CNC shield GND. The power supply for the shield is 24v and I have used the Universal Gcode Sender to test out the motor movements and limit switches. I want to add a laser which requires a 12v power supply and can accept a PWM signal.
My intent is to connect the 12v +/- from the new power supply to the laser, and the PWM wire to the shield's Z+ positive connector. I've read that I need to connect the new 12v GND to the shield GND. I assume this means the GND connection on the power supply and not the V- connection which is going to the laser. If so, I plan on connecting it to a second ground pin on the capacitor board which connects to the shield GND. Will this work?
The laser will come with a DRIVER BOARD.
That board will have connections to go to the GRBL shield AND also have another connection for the 12 volt supply that is independent of the GRBL shield.
Have not found any need to use a seperate ground for the extra supply.
Many Chinese lasers use the -V to denote the negative or the ground side which in this case and at these voltages are usually interchangeable terms.
Use the Z+ and the GND from the grbl shield to the PWM and PWM gnd (PWM -)
Normally there is a short cable included and you simply need to extend that (quite a bit) using a two pin DUPONT terminated cable.
The driver board may also have a TTL/PWM jumper or switch which would need to be set to PWM for most normal usage.
My own preferences here is a thin shielded cable for the long run but it is not always needed for most people. When extending the cables do NOT use thinner wire but either keep it the same or the next gauge up.
Links to the exact hardware are always useful.
Could you take a few moments to Learn How To Use The Forum.
It will help you get the best out of the forum in the future.
Other general help and troubleshooting advice can be found here.
Bob.
