Starting new project - Any ideas/suggestions?

Hi, I would like to make a lamp dimmer.

DC not AC, I have an led lamp running on 4.5 volts (3AA). Currently you can only on /off. I would like to be able to control the light intensity as well. I would like to control the lamp by touching any part of the lamp or dedicated place or somthing. I would like to have a starting point for this project and would like some advise about what PIC to use & how to go around in the programming part.

I would like to know how to make the PIC sense the touch and control the intensity etc.

All inputs are welcome. Thanks

Here is an example of a touch sensor:

http://www.picbasic.co.uk/forum/showthread.php?t=2671

And here is the smoothest dimming, using mibam

http://www.picbasic.co.uk/forum/showthread.php?t=10564

PWM hardware can also be used for dimming, as well as interrupts. But I think mibam is better.

You could use a chip as small as the PIC12F683 for this. Start out by just trying to dim a single LED, then later worry about how to drive your larger LED lamp.

The 16F72x parts have some "built in" touch sensor functions.
I've used them. Most of the relevant data sheets, and some of my "early progress" with touch sensors can be found here:
http://www.picbasic.co.uk/forum/show...ght=capacitive

They work pretty well. The real trick is doing appropriate averaging to kill any noise spikes from triggering the touch sensors. One of my "early version" temperature controllers will increment it's set temperature a couple of degrees every time I turn OFF a particular fluorescent lamp in the same room. :(
I've been too lazy to open it and fix it....


steve

I made a bed side lamp out of a 3W led. touching the metal base of the lamp turns it on, a second touch dims it, a 3rd dims more and a 4th turns it off.

All I used is an 8-pin 12F683 to do MIBAM for the dimming and just the stock standard built in ADC to do the touch sensing.

After a little calibration, ive been using it for nearly a year and have never had a false triggering of the touch sensor.