Hello,
I'm after some inspiration as to how to crack a particular nut!
What I seek is to send information about which position a 5 position rotary selector switch is in over just two wires ...is a ground & signal wire.
I'm figuring that there may be an existing chip solution where 'input pins' are all connected to the 5 switch poles - the chips input pins are subsequently scanned & when there's a change at the input pins, it sends an RS232 signal - this is receved by a corresponding decoder chip which reverses the procedure ...the receiver chip's output pins could then drive some relays to replicate the switch's function.
Is there any soliution out there (not even sure what keywords to search for!)
I'm after some inspiration as to how to crack a particular nut!
What I seek is to send information about which position a 5 position rotary selector switch is in over just two wires ...is a ground & signal wire.
I'm figuring that there may be an existing chip solution where 'input pins' are all connected to the 5 switch poles - the chips input pins are subsequently scanned & when there's a change at the input pins, it sends an RS232 signal - this is receved by a corresponding decoder chip which reverses the procedure ...the receiver chip's output pins could then drive some relays to replicate the switch's function.
Is there any soliution out there (not even sure what keywords to search for!)
5 different resistors...like in some portable media players' remotes...
http://rasher.dk/rockbox/WikiRescue/IriverHardwareComponents-r1.52 - 06-16_files/remote.gif
http://rasher.dk/rockbox/WikiRescue/IriverHardwareComponents-r1.52 - 06-16_files/remote.gif
Rodeodave said:
Absolutely right!
When security devices where not digitally encode they used resistors in the keyfob.
You can do the same by using say 4 x 1K resistors and read it with an A/D or just a quad op amp with four thresholds set matching the resistors. (position 1 = 0V and not needed to be deciphered)
Nico
- Status
- Not open for further replies.