Jon Williams Assist regarding past post

bobsmith

Probably not -- what you may want to do is some sort of buffer/driver like the ULN2003/ULN2803.· The attached schematic shows one line connection.· The 330 resistor is based on putting about 20 mA through the LEDs.· At 1.5 volts each, there is 6 volts across the resistor.· 6 / 0.020 = 300, 330 is the closest "standard" value; this results in 18 mA through the LEDs.· The resistor should be 1/4 watt (0.018 x 6 = 0.108 x 2 = 0.216, hence 1/4 w).

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Jon Williams
Applications Engineer, Parallax
Dallas, TX· USA

<!-- Edit -->

Post Edited (Jon Williams) : 1/3/2005 5:37:01 AM GMT

Jon Williams

Sure.· The ULN2x03 is a very common part and you can get them just about anywhere that carries electronic components (Digi-Key, Mouser, Jameco, etc.).· For convenience, we carry them too:

http://www.parallax.com/detail.asp?product_id=500-00005

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Jon Williams
Applications Engineer, Parallax
Dallas, TX· USA

bobsmith

How do I hook everything up ... do i need a stamp? if so how do i program the stamp to activate the lights.

Jon Williams

Wow, those are huge questions.· If you want to do something fancy with the lights (like on a police car or ambulance) then, yes, you will need a BASIC Stamp to control the sequence.· If it's just on and off -- you don't even need the ULN2x03; but your original post indicated that you wanted to control the LEDs in some sort of pattern.

You might consider a read through "What's A Microcontroller?"·· It's a great way to get started and will help you with the whole hook-up thing (in general).· Once you have that sorted, it's a matter of determining what you want the lights to do when on.· Here's just one example (I've supplied BS2 code but this could easily work in a BS1 as well).

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Jon Williams
Applications Engineer, Parallax
Dallas, TX· USA