The Weekend Project 1 – GRBL LCD Display – Part Two – Fail and Recovery!

A recap of my weekend plus monday and tuesday morning!

The aim of this project was to get an LCD display to display GRBL’s position. The way I was going to achieve this was to spy on the TX and RX lines from GRBL using the arduino pro mini as the proxy. This was a fail! D’oh! But we learn from mistakes. The way I had in my head to get it working didn’t end up working! When you connect to the RX and TX lines on the arduino it disables the USB connection as they are both linked.

While trying to do this I stumbled across a library called AltSoftSerial – – this is great! It emulates serial ports on arduino. This was my next approach, use a virtual serial port and get the serial and spy on it.

I started working on some demo code to try and get this working when I did some googling. I stumbled across a great thread on the shapeoko forum where a very clever chap called Frank had already done this! Brilliant!!! The project is called XLCD and goes along with his XStepper project. This also works with GRBL – success!

I went about getting this to work on monday morning. (The weekend was a bit short – we are having new windows fitted in the house after waiting 7 months so we were busy tidying the house ready for the installation.) The forum thread was great – downloaded all the libraries and went onto the github page and downloaded the 0.2 version of XLCD. All set. Or not!

I was having no end of problem getting it to compile! All sorts of errors showing! I bummed out – I spent nearly the entire day and night monday trying to sort these problems out. I reached out to someone on the forum to help and Frank himself replied with his entire Arduino folder zipped and dropboxed over! I cannot thank him enough for this! Turns out it was just a problem with my Arduino on OS X (I’m an apple fanboy!). I installed Parralells Desktop onto my machine and installed Windows 7. I loaded up his arduino.exe from the folder and boom – compiled and uploaded! Wow! Thats all it was!!

Back to the breadboard – wired everything up following the sketch inputs apart from the buttons and rotary encoder – I’m waiting for a batch of PCB’s from China and it happens to be Chinese new year! They should be here in around 3-4 weeks! It all works though and I’m more than happy with this! I’m going to order a new 20×4 LCD display to use as a permanent install on my CNC now!

Attached below are the working images of the setup:

2015-02-17 12.21.17 2015-02-17 12.21.25 2015-02-17 12.31.25 2015-02-17 12.21.20

I am willing to help anyone else out with problems getting this to work – just pop me an email on my contact page and I’ll be willing to send over anything they want – I’m going to upload the Arduino folder below for anyone else to access free of charge. This should help!

Leave a Mesage