Comments on: The GitHub Stoplight

By: Andreas

Andreas — Fri, 21 May 2010 04:15:12 +0000

Sweet stuff. You could extend it so that it lights red OR green while lighting yellow to indicate what the previous build result was during building.

By: balloonatic

balloonatic — Thu, 20 May 2010 12:18:58 +0000

The idea is a nice one and I might have a go myself.
However: short of talking about how you remembered to inhale and exhale throughout, I’m not sure you could have drawn out your explanation, of interfacing some relays to a microcontroller and using an off the shelf ethernet library, any longer than you already have. Good lord.
And yes, the 0.1mm of paint is insulative but you really have to do a better mounting job – it’s not something that a teacher would ever accept of a school student in technology class, let alone it being a project that uses mains. Why you you think people earth appliances?
It’s good that you’ve learnt a lot doing this but please be aware that you’ve made a fairly poor job of a relatively trivial task. The good news is, the only way from here is up.

By: Maintenance Man

Maintenance Man — Thu, 20 May 2010 11:55:45 +0000

Reminds me of my old EE course. The professor brought in a black box we needed to control. The box interfaced with a set of traffic lights. Good stuff.

By: Richard Bradley

Richard Bradley — Thu, 20 May 2010 11:16:50 +0000

@Greg – yes, it has to plug into a computer (and one with a parallel port, which isn’t that common any more :-).
The pros are that it’s a great deal easier to write (and debug) a ruby script which scrapes a web page and changes the lights than program an Arduino. The cons are that there has to be a PC on and connected by a wire to the lights. However, that’s not an issue in my office.
(There are USB versions of that relay board — I wish now that I’d paid the extra €5 or so to get one.)

By: Greg Borenstein

Greg Borenstein — Thu, 20 May 2010 09:09:39 +0000

Richard — Cool project. That parallel port relay board looks interesting. Do you have to keep it plugged into a desktop/laptop? That was part of why I went the arduino-ethernet route: I didn’t want the GitHub guys to have to keep a laptop plugged into the thing at all times.
John — Thanks for the defense there. I think you captured the spirit of this project perfectly.

By: Richard Bradley

Richard Bradley — Thu, 20 May 2010 09:02:20 +0000

Looks great! Strange that you got US style traffic lights from a UK seller. I made a similar set to monitor the build on my current project at Softwire, but I had UK traffic lights which a) use low voltage AC and b) have a plastic body, so my build was without the scary electrocution risks you seem to have faced :-) I used a parallel port relay board, rather than an Arduino, so that I can control them with a ruby script. It was much easier to program.

By: Greg

Greg — Thu, 20 May 2010 08:46:47 +0000

GitHub + Arduino? Two great things combined in a single package…. 🙂
Thanks for the writeup. Can hardly wait for tomorrow to get back to tinkering…

By: John

John — Thu, 20 May 2010 08:46:02 +0000

@archels & @Gward – this project isn’t about being a professional EE, it’s about having fun and doing something that pops into your mind. And just because the Arduino is High-Level doesn’t make it hipster, Arduino makes it accessible to people who have creativity and want to produce objects and not worry about the “right” way of doing something. EE’s shouldn’t feel endangered but rather enjoy people exploring electronics.
Greg, nice work! Great documentation!

By: Ben Combee

Ben Combee — Thu, 20 May 2010 08:32:21 +0000

If you need to rewrite this, check out my Webduino library (http://webduino.googlecode.com) — it’s a webserver implementation on the Ethernet shield that simplifies the networking bit.
I’ve not tried adding Wiznet reset logic to the library, but that sounds like a nice change for the next version.

By: John E Connolly

John E Connolly — Thu, 20 May 2010 07:14:41 +0000

This is great. We use buildbot at BUG Labs to automate our build process and this could be a cool tie-in. We've done some similar work with an arduino on our "MotherBUG", whereby we use an arduino (which is connected to our VonHippel Module to control a servo motor, which in turn controls the orientation of the BUG and camera. Have a look: http://motherbug1.buglabs.net/service/Servo. We've even created a (still beta) BUGDuino module for people out there who are looking to do similar things. Great post!