I'm new and have some questions before buying materials!

Projects General Guidance
10

Ok, yes it's 40 wires not 80 :slight_smile:

Now some more serious questions, I plan to buy a 16 opto-isolated relays board from Sainsmart. But obviously with my sensors, touchscreen, sd card... I guess I ran out of pins on the arduino already.

  1. Can I use this instructable about multiplexing for controlling each relays:
  • individually,
  • or simultaneously (for example: the 10 relays [1, 3, 4, 5, 6, 9, 11, 12, 13, 15] turned ON)
  • or all at once

Or maybe using "daisy-chaining" like in this tutorial ?

  1. I don't think I really understand multiplexing yet, but I think in the first link (instructable), it's only possible to control 4 leds simultaneously (so in my case, 4 relays), correct?

  2. Last thing, can I use the multiplexing for reading values of many sensors (temperature, etc)? I probably don't need that, but maybe! :slight_smile:

EDIT: I have posted new topic here: http://arduino.cc/forum/index.php/topic,123906.0.html , I will probably have more views :slight_smile: