Pages: [1]   Go Down
Author Topic: Corruption of signals over long wires  (Read 518 times)
0 Members and 1 Guest are viewing this topic.
Sussex UK / CT USA
Offline Offline
Edison Member
*
Karma: 0
Posts: 1028
Forums forever
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Suppose I have an Arduino in my living room and a 50' wire to a doorbell type swich, normally open.

Are there any steps I can take to protect the Arduino from "seeing" false switch closures arising from voltages induced in that long wire (read "antenna") when big motors around the house (heating pump, refrigerator) throw out "noise"?
Logged

Manchester (England England)
Offline Offline
Brattain Member
*****
Karma: 516
Posts: 31579
Solder is electric glue
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
Are there any steps I can take to protect the Arduino

Yes

http://www.thebox.myzen.co.uk/Tutorial/Protection.html

Also adding capacitors at the arduino end can help. Also consider using the analogue input to detect the push switch. That way you can set your own thresholds instead of having them set for you by the digital input pins.
Logged

USA
Offline Offline
Jr. Member
**
Karma: 0
Posts: 87
Who is John Galt?
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Use the same noise-suppression technique seen in rs-422 wiring that makes it superior to rs-232 wiring.

See: http://en.wikipedia.org/wiki/Differential_signaling
Logged

Lancashire, UK
Offline Offline
Edison Member
*
Karma: 8
Posts: 1992
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

You could decrease the value of your pullup/pulldown resistor.  Hold the sucker high or low by brute force and ignorance.......  smiley
Logged


Pages: [1]   Go Up
Jump to: