Connecting to the CNC

Overview

The CNC is reachable via a Rpi over the network which acts as a serial proxy

If using Windows 10 then I’d recommend using a separate desktop window, and using a browser other than your main one (such as Firefox or chrome) so that you can continue to do other things (such as browser the web) with your main browser etc. without interfering with the milling process.

Try to avoid using the Microsoft Edge Browser as an alternate browser, it seems to be okay sending commands to the mill, but I’ve noticed the controls become locked up / unresponsive during the process of sending G-Code / doing the actual mill.

Powering Up

First we need to power up the mill


The grbl board and the rpi board are powered separately and are powered on all the time regardless.
Because of this reason it’s important to perform a homing operation when turning the power on

Starting Chillipepr

Next we’re going to start up Chillipepr.

Chillipepr is a online system consisting of a series of web pages and JavaScript scripts pulled in from other sites.
There has been an attempt to create an offline version, but for now it’s easier just to browse the online version.
The JavaScript within Chillipepr will connect to a Serial Port Json Server located on the Rpi.

Note the link is different than normal chillipepr / grbl as we’re using firmware version 1.1 instead of 0.9

Connecting Chillipepr to the CNC

If you’ve never connected to the CNC before then select Scan for Hosts.


This should discover the server to connect to, select this to connect


In the drop down lists make sure Grbl is selected, and the maximum baud rate 115,200
The older versions of Grbl used to use a slower baud rate of around 9600, but the later versions use the max 115,200 speed instead.

Once you’ve selected Grbl in the drop down, click the tick box on the left to initiate the connection to the board.


Homing

One of the first steps to do after powering up the mill is to home the device.
See the Jogging Section on how to do this.

Without homing there’s the risk the machine may go too far downwards.
as this is limited by software limits which rely on grbl knowing where the home position is.
Or the machine not going far enough down if it thinks it’s in the wrong place.

Connecting via Http

If you want to instead connect to the CNC via a Serial Console, it’s possible to access the serial port via the browser

To send a command like $$ which lists the grbl settings we can use the following within the web client

send /dev/ttyACM0 $$