Master Slave connection in Arduino?

Hi

I need to have one master arduino uno, and many slave arduino uno's, in which if I send some specific number from master arduino uno through serial monitor, every slave should receive it, and whichever slave is programmed to receive the specific number should send out data, and other arduiino slaves should do nothing at that instant, and master arduino uno should receive information and display it in serial monitor, I am planning to connect everything using serial monitor.

This is for: I have about 12 temperature meter in different part of my barracks using lm35 temperature sensor and arduino uno displaying the temperature, Now I need to have a single console in the ground floor which receives temperature data from slave temperature meter and display it in serial monitor, because I cant go everytime to check the temperature, Now I have planned to use above method, will it be feasible for this, wiring connections are done already for master and slaves. Now I need to know how to establish the wiring and code? Can you please help me in this? I am willing to have different ideas other than this also

Several of the different wireless systems available will allow you to do this.

If you want to make it wired, then the I2C bus will allow one master to address many slaves. I2C is not likely to be useful past 20m although with some effort 100m should be possible.

I would suggest the NRF24 2.4Ghz wireless transceivers. One receiver can listen for up to 6 transmitters. They are pretty inexpensive, too. I just got 5 for $9.00 on Amazon so Ebay might be even cheaper. . I have seen range of 60 feet through a couple of walls, so line of sight will be further. Each transceiver uses 5 pins (3 for SPI and 2 chip selects).

groundfungus:
One receiver can listen for up to 6 transmitters.

I suspect this limitation is because of the number of different channels.
And I imagine that if all the slaves use the same channel (but not at the same time) you could have a much greater number of slaves.

…R

Robin2: I suspect this limitation is because of the number of different channels. And I imagine that if all the slaves use the same channel (but not at the same time) you could have a much greater number of slaves.

I suspect this too :)

wiring connections are done already for master and slaves.

Add a RS485 transceiver to each device.
See Figure 9 of attached.
http://www.digikey.com/product-detail/en/MAX485CPA%2B/MAX485CPA%2B-ND/948026

AN763 RS485 termination.pdf (234 KB)

Add a RS485 transceiver to each device.
See Figure 9 of attached.
http://www.digikey.com/product-detail/en/MAX485CPA%2B/MAX485CPA%2B-ND/948026

Yeah, one more friend of mine also suggested to go far rs-485 setup, but he doesn’t knows much about it, where should I connect twisted pair wires?, what is data-in and data-out, before you could answer this, I will explain my system in detail.

I have LM35 temp sensor, values are read by Arduino Uno( AnalogRead) by doing some calculation I display the temperature in 16 x 2 lcd display, which is enclosed in some case powered by 12v 1 amp adapter fixed in wall. I have around 12 temperature meter like this. Now where should the DATA IN and DATA OUT in rs485 should go in Arduino, and to what pin does the twisted pair cable connects.?

I have attached the pic which you referred to. Adding to this I need to see the data in my pc.

Thanks.

My post about RS485.

Thanks for the link, let me go through it..