Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

On the ATmega168 chip - are you familiar with the AVR line of chips? The Arduino is one product that makes it easy to program without know all about C++ or any of the other stuff. Heck, can't be too hard, even I can program simple stuff:)

Do you use ExpressPCB program any? Neat little program for drawing schematics and PCB layouts - that's what I'm using most of the time. Am starting to fool around with Eagle some also. Eagle is more powerful, but a more learning curve... more like AutoCAD.

I'm using a temperature sensor (AD22100) to send a voltage signal back to the m168 chip (ATmega168), then the m168 sends a OFF/ON signal to a MOSFET to turn an electronic relay on/off. I could have used a mechanical relay also, but just happened to have the electronic relay courtesy a fine Gentleman who hangs out on this and other groups. I plan to do some Pulse Width Modulation of the signal to control the temperature a tad closer than currently controlled. A person could also use the PWM to slow the motor down if desired.

The temperature and setpoint are displayed on a LCD (also courtesy of same gentleman) - really a slick little controller.

"IF" you're interested in building one, I'll be more than happy to help - I can send you the PCB layout in PCBExpress so you can etch a board (or perhaps etch one for you if need be?) and work with you on the programmed chip.

I worked the code out on a breadboarded setup, then etched the PCB and transferred the circuit.

It's not fancy, but it does work.

Ken H>