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Topic: how to increase more I/O pins with all individual controls (Read 2171 times) previous topic - next topic

jonyjakee

I am trying to contorl more Appliances connected to in my home. My needs makes me to control the appliances single or multiple at a time.

Please help me in increasing more I/O pins.(even with many micro controller if solution needed)

CrossRoads

How many, and how are they controlled?
There are many expansion options.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

jonyjakee

Quote

How many, and how are they controlled?
There are many expansion options.


nearly 100 appliances, controlled by android application through wishiled.



CrossRoads

Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Frisky

http://asynclabs.com/store?page=shop.product_details&product_id=26&vmcchk=1
I guess it's a shield

CrossRoads

And what are the appliances? 120V items? 240V items? How are wired now, or how will they be wired?

I have a 2000 sq ft, 2 story home I don't think we even have 50 dual plug outlets, let alone 100 appliances.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

jonyjakee

Quote

And what are the appliances? 120V items? 240V items? How are wired now, or how will they be wired?


i am connecting 240v items(fan, tubelight, blub,..etc). 

5v supply is connected in switch and apliances are connected with relay.

so i can control both in switch board and using android mobile which will control appliances connected to the relay.



RacerX89

#8
Jul 07, 2012, 12:41 pm Last Edit: Jul 07, 2012, 12:44 pm by RacerX89 Reason: 1
You may want to take a look at serial to parallel shift register chips. It turns 3 I/O pins into 8. They can also be cascaded, so 3 pins can become 16, 24 ,32... depending on how many chips you link together.

http://www.sparkfun.com/products/733

Basically you feed them a byte value (0-255, which is an 8 digit number in binary) and the 0s and 1s correspond to 8 pins on the chip which then become high or low. So lets say you want to turn pins 2 4 and 5 high and keep the rest low. You'll want to send it the value of 176 which is "010110000" in binary notation.

http://arduino.cc/en/Tutorial/ShiftOut

AWOL

"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

Graynomad

Using a single master Arduino for an entire house has pros and cons but for my money the main con is wire length as I think AWOL is alluding to.

Unless it's a very small house the wires will be too long for reliable sensing and maybe even control. Also of course you need 100 wires. 

My preference would be for a network of small controllers, say one for each room. The down side is that the programming gets more complicated.

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

RacerX89

the wires will be too long for reliable sensing and maybe even control.
______
Rob


For sensing definitely, but maybe not for control if everything is either high or low to control a relay. Nevertheless, the I/O board could never energize 100 relays on it's own. I'd certainly use general purposes npn transistors and have them trigger the relays with 12v. That way I don't think the length of wire would be an issue, so long as the gauge is reasonable.

-Tony

jonyjakee

i am getting an idea to use many arduino boards. one is master arduino board and many slaves to it. master arduino should send a data to all the slave arduino boards, all at the same time slaves should recogonise that the data is sent to the particular slave to Switch ON particular appliances.

will this work effectively.

Graynomad

#13
Jul 11, 2012, 12:56 pm Last Edit: Jul 11, 2012, 12:59 pm by Graynomad Reason: 1
Quote
will this work effectively.

Yep.

Have a good search through the forum there's 100s of post about such things but as I said above a network of Arduinos connected with RS-485 is one way to go.

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

jonyjakee


Quote
will this work effectively.

I said above a network of Arduinos connected with RS-485 is one way to go.


i am new to networks. please help me to understand this networks and RS-485

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