What kind of microcontroller do i need

idrisb

i am trying to build a breathalyzer watch for my senior design project. i am planning on using a alcohol sensor module that i ordered through parallex. This is the site for it below.
http://www.parallax.com/Store/Sensors/GasSensors/tabid/843/CategoryID/91/List/0/SortField/0/Level/a/ProductID/695/Default.aspx. i am leaning on ordering a pic microcontroller but not sure which bit to go with. i also need a led display or lcd display for the watch. i am planning on using led's to indicate the bac levels for the breathalyzer.

LoopyByteloose

The simple answer is that with the right software, any micro-controller will likely do. But if you wan to use Free software and an inexpensive microcontroller, you choices become much more limited. The Propeller 40 pin DIP and SPIN are a real bargain.

Of course, if you feel comfortable programing a PIC in assembler and have a programer for it - that might be cheaper. You can build a programing interface for a Propeller from a few transistors and use an existing RS-232 port.

Mike G

@idrisb, The STAMP does everything you want plus all the software is a free download away. The bottom of the Gas Sensor manual shows the PBASIC code.
http://www.parallax.com/Portals/0/Downloads/docs/prod/sens/27904_27930-1-2-GasSensor-v2.2.pdf

idrisb

ok thanks. i am new to microcontrollers and haven't taken a class in microcontrollers. Like i said earlier i am trying to build a breathalyzer watch.my original plan was to make a breathalyzer wrist watch but considering making one that attaches like a keychain. do you think i can use the same microcontroller for the digital watch or would i require two microcontrollers. To build a digital watch, i was considering using a led display. do you have any suggestions on the type of display to use. I don't need a big display