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Topic: How to use 4 relays and 4 sensors? (Read 868 times) previous topic - next topic

1Pats

Jan 02, 2011, 04:24 pm Last Edit: Jan 02, 2011, 09:16 pm by 1Pats Reason: 1
Hi.
I am planing to create some simple climate control automation for sun room. I have bought arduiono clone, together with data log shield, number of sensors and relays from nueletronics.
http://www.nuelectronics.com/estore/index.php?main_page=index&cPath=7&zenid=2d914d1482bdca4c30be6616be86d9fd
Everything works fine. I was able to run all samples, verified work for each particular sensor  etc., do not have problems with programming, but I cannot find workaround for following statement:
Analog lines 2,3,4 and 5 (aka digital lines 16-19) are brought to BOTH P6-P9 and to P1/P2.
see:
http://sheepdogguides.com/arduino/ar3ne1nop.htm

So it means - if I have two  double relays from nulelectronics  attached to P1,P2, then I have only two pins left (P4,P5) for sensors. Or vice versa-I would able to have 4 sensors, but only one set of relays attached to P1 or P2. But intend is to control temperature, humidity, amount of light and commutate heater, fan, pump,lamp.
I did test - attached buzzer to one of these pins, and it is buzzing when relay is on . Setting buzzer mode to input, switches off also relay. It confirms what is said-e.g. relay and buzzer worked like one device.

Tried to find some info here. Looks like, I am using wrong keywords.
Could you confirm this significant restriction  and suggest workarounds?


Grumpy_Mike

Quote
Tried to find some info here. Looks like, I am using wrong keywords.

Not so much of the wrong key words more in the line that you are trying to use a system that has insufficient capabilities for your needs.
What you need to do is to either expand the analogue inputs or the digital outputs by using an analogue switch or shift register.
http://www.arduino.cc/playground/Learning/4051
http://www.arduino.cc/en/Tutorial/ShiftOut

1Pats

Thks a lot for your replay. Else I was unsure about my conclusions. Will consider what to do next.

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