The k8023 could also be converted very easily to provide comms over fibre optics instead of the current loop.
Audio system TOSLINK fibre optics would work fine. just replace the input transistor (and it's associated resistors, led etc)of the reciever with a TORX177 and at the controller end you'd replace the transistor and its associated components with a TOTX177 , you'd have to connect vtx- of the controller to gnd as well.
OK. i just looked up the transmission distance using those part numbers and you'd get about 5 m. lol.
However there are plenty to choose from here- http://media.digikey.com/pdf/Data%20She ... OSLINK.pdf some are good for 1000m.
Hey everyone, with the velleman do you need a specific type of wire for the serial communication? Also how would you wire it up to a switch on the controller end.. Whenever I do it never seems to work the lights never come on only the two power lights. The relays I am using are small enough to be powered by the reciever end but I can't seem to get it to work, any simply way to explain this to me? Thanks, help would be appreciated.