Henry_Best:
matelot:
Henry_Best:
matelot:
the atmega 328 has 14 digital and 6 analog ports wouldn't this be enough?
I would just drive relays near the board and run the circuit from them.That would depend on the voltage & current needed to light the signals, remembering that the 4-aspect signals can have two lights lit at the same time.
The second line says 'i would just drive relays near the board and run the circuit from them' ?
That still doesn't tell me what voltage you're using. 240v AC would require expensive waterproof steel reinforced cable, if you're burying it. 12v DC, not so much, but you'll have to take into account the voltge drop over 200yds.
Sorry Henry I don't want to sound unhelpful but the uno only needs to run relays or even opto isolators such as
http://www.ebay.co.uk/itm/280947061304
so the issue of power for the LED's is not important.
The whole circuit runs on 24 v dc but the board for the uno chip will have a 5v regulator , a 7805 , running it.
The present system is running the LED's at the moment but with boards in each signal box providing the correct switching. I want to run the circuit from a program chip and send just wires to each head.
That way I can also run an indication board at the signal box, Which I can't do at present.
I will take into account the voltage drop and change the inline resistors to adjust the brightness.
I do appreciate you keeping with me, thanks.