PDA

View Full Version : digital input resistance values?



James D. Lane
06-18-2005, 11:50 AM
Hi guys, I am new to the bs2p40 and need to set up several pushbutton and relay type inputs, the text book from the Basic Stamp Discovery kit shows 220Ohms to the button and the button to source voltage, ie 5 Vdc, and then shows a 10kOhm resitor from the 2p40 input to ground.· I am out of 10k resistors but have several 830Ohm or 860Ohm or somewhere in that range of resistors.· I know the 10k is being used as a basic pulldown resitor to give the input a good readable 0Vdc input.· Can the processor inputs handle less resistance for a pull down resistor as noted in the 8xx Ohm region.· I would run to Radio Shack and get more 10k's but my time is out and I have to finish this project for the client now.
thanks,
James
·

Chris Savage
06-18-2005, 12:12 PM
James,

·· You should be able to use the 860 ohm resistors without issue.· The difference in current draw·is negligable.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

James D. Lane
06-18-2005, 12:42 PM
thanks Chris, I will continue soldering resistors tonight.
James