I have a small problem that I need to sort out. It concerns much of what I have read here on this forum, but doesn't answer the problem that I have.
I have built a laser engraver and have it working fine using a cloned Arduino UNO and a cloned CNC shield v3. Firmware is GRBL 1.1h
I have also purchased a Lekn G-sender standalone controller that connects to the CNC shield TX and RX pins plus the 5v and Grd pins.
Once the controller starts up it can be used to control many things that I would normally do with the computer, and also a SD card holds all the prepared files that are used for the laser engraving.
The problem is, once the computer USB is disconnected, the system dies as there is no power.
Also when the G-sender is attached, the computer will not work with the system.
To overcome the problem with the computer not working, I cut the wires to the TX and RX and added a double pole switch so that I could switch between the G-sender or the computer.
Still have the problem of the power. If the USB cable is disconnected from the computer, the G-sender has no power.
Does anyone know if it is possible to add a small 5 volt power supply to the Arduino UNO so that my machine can work completely without the computer? And when I want to use the computer it would be a matter of just plugging in the USB cable.
I was thinking about using a small step down from 12 volt to 5 volt, so only one power supply would be needed for the machine.
I am not sure about the dangers of wiring in an external 5 volts, I don't want to blow things up.