Saturday, April 23, 2011

Limit switches, part 2

In the previous post, I showed how I added limit switch inputs to my CNC driver box. Now its time to attach the actual switches to the machine.

Thursday, April 21, 2011

Limit switches, part 1

The CNC3040 machine doesn't come with limit switches and having already crashed the machine once I thought it was high time to add ones. The problem is that the driver box doesn't have inputs for the switches. My first idea was to build a passthrough box to break out the input pins, but peeking inside the case I found a nicer solution.

Wednesday, April 13, 2011

Griffin powermate + EMC2

I'm currently designing a physical control panel for use with EMC2 and for that I needed to learn how to use the HAL. HAL is EMC's hardware abstraction layer that provides a sort of virtual breadboard for connecting components, both hardware and software, together. One great thing about it is that it's really easy to write your own userspace HAL components in python. A short tutorial from EMC's documentation shows how. Also, Just Milling Around has a great tutorial on how to interface an Arduino with EMC using a python script.

As an exercise before getting started with my control panel, I decided to write a driver script for a piece of hardware I already have: A powermate jog wheel. My script creates two HAL pins: An output pin that can be connected to axis.N.jog-counts and a boolean input pin to turn the LED on and off.

The powermate HAL script is available here: