Bluetooth connection

You can use 3dpBurner wireless by a cheap way using a bluetooth connection. This is very comfortable on many times and situations... but note is not valid/recommended for gray scale engravings .

Why?

For vector works there's usually a GCODE line for each vector line/arc and no much laser power variations so no problem, while for raster image gray scale works there is a GCODE line for each pixel and a lot of laser power variations, this generates a lot of data traffic. The bluetooth connection is unable to maintain a smooth stream being the GRBL buffer empty for moments. These "gaps" translates to micropauses on stepper motors producing a non smooth engraving.

You can install a bluetooth module and use it for vectorial works and swap to USB connection for gray scale works.
Personally i always use the bluetooth connection except when burning gray scale images.

You need:

A cheap HC05 type bluetooth module with breadboard.
Take care Arduino UNO works with 5v levels  and the module can be 5v tolerant or not, most of these module support 5v only on powering pins but not on IO pins, If your module doesn´t support 5v on IO pins or you are unsure, use 1k resistor on the RX pin of your module, this should limit the current on that pin and prevent to burning the clamp diode inside chip.

For configuring the module i recommend to buy a FTDI device (also cheap) or any other USB to UART TTL conversor. If your bluetooth is not 5v tolerant or you are unsure use one of these FTDI 3.3/5v capable and set it to 3.3v (or use a 5v one with a pair of 1k resistors on RX and EN pins of the bluetooth module).
If you don have/want to buy the FTDI check this link for use Arduino as FTDI device.

Gomcu module HC05 5v IO tolerant

Gomcu module HC05 5v IO tolerant

Other module HC05 no 5v IO tolerant

Other module HC05 no 5v IO tolerant

FTDI module

You also need to do a small mod for powering arduino from 12v input instead the 5v USB port (obviously USB is not connected when you use bluetooth).

On the CNC shield solder a wire between +12v IN from power supply and Vin pin header. Don´t worry about use 12v in and 5v from USB at same time. Arduino do de job itself by selecting automatically USB power if no 12v in detected.

12v powering mod

12v powering mod

Configuring the module

If you are not familiar with these devices you can check the HC05 datasheet and/or other documentation for configuring it, there are a lot of info about this on the web.

Basically you need to put a high level the EN pin, while powering the module. Some breadboards has a tactile switch for this and some ones has a pin that must be tied to 3.3/5v.

-Check you breadboards pin label order

-Resistors (1K) are optinal (for no 5v tolerant devices)

-Switch is optional (for no built in EN switch devices)

After this, the module enter in AT mode and the button can be released, the module starts at default UART settings (38400, 8, 1, 0, 0) and can be configured by using the next AT commands (may be slightly different depending the bluetooth fw version).

>AT
OK
>AT+ORGL
OK
>AT+PSWD=5678
OK
>AT+UART=115200,0,0
OK
>AT+NAME=3dpBurner
OK

Replace the password (5678) and the 3dpBurner name by your prefered one. After this the module is now configured and can be disconnected.

Wiring the module

-Resistor (1K) is optinal (for no 5v tolerant devices)