Dimming Lights Update

jagrifen

There was a great article in Nuts and Volts a few years ago that showed how to create an 8 channel dimmer using the Parallax S/X chip. I was wondering if anyone has tried to rewrite this program for the propeller. I found a great object that begins to do what I am looking for but it only supports one channel. Ultimately I want to control 24 channels. Any help would be greatly appreciated.
Thanks!

jmg

Doesn't the DMX512 handle this ?

JonnyMac

I'm working on a four-channel version for EFX-TEK (the FC-4+). It has ports for TTL serial IO and RS-485 (DMX or any other protocol that runs on '485). The board has passed the initial tests; I'll be finalizing the phase dimmer next week.

BTW... my N&V project was an eight-channel variant of the original EFX-TEK FC-4 (which I also designed and coded).

DynamoBen

I have an open source project that might be helpful. Schematics and code are there, let me know if you have questions. http://code.google.com/p/propcontroller/

I suspect this sample code will be the most useful. http://code.google.com/p/propcontroller/source/browse/#svn%2Ftrunk%2FProjects%2FDMX_128

jagrifen

Thanks for the help everyone! Ben, I think what I am trying to do is very similar to what your project offers. Luckily my deadline just got extended so I have a bit of time to play around.

JonnyMac

I was fighting a noise problem on my AC input -- fixed it with some code. The attached 4-channel code works for me, but to be honest I don't have a lot of time on it (hence I haven't moved it to ObEx yet). After some testing of incandescent lamps I'm going to add an optional curve to improve the output. Adding more channels will not be a problem if you need more.

Note: Code updated 3/30 per suggestion from ke4pjw

ke4pjw

jagrifen wrote: »

There was a great article in Nuts and Volts a few years ago that showed how to create an 8 channel dimmer using the Parallax S/X chip. I was wondering if anyone has tried to rewrite this program for the propeller. I found a great object that begins to do what I am looking for but it only supports one channel. Ultimately I want to control 24 channels. Any help would be greatly appreciated.
Thanks!

I used that exact article as a guide to make 16 channel dimmers. I simply padded the the "accumulators" with a value of $FFFF_FF00 so that it would roll over when it reached 256. Works great!

http://www.youtube.com/watch?v=oqrkTCQr85c

JonnyMac

I simply padded the the "accumulators" with a value of $FFFF_FF00 so that it would roll over when it reached 256. Works great!

Excellent idea and I can confirm that it works great. Thanks for the tip!

jagrifen

Awesome! I'll have to try playing around with that.