Multiple transmitters One receiver

Wireless & IoT
1

I ve been introduced one year ago to a project ( i can’t remember the designs that’s why i ask here ), where the guy had one receiver hooked up to a mcu ( arduino maybe) and up to 99 !! transmitters serially coded hooked up to a motion sensors.

The designs of the transmitters were very small coin cell batteries, motion sensor and RF ( size of a thumb nail) and cheap…

So basically i want to know what kind of rf were used for that one receiver to 0-99 serially coded transmiters…

oh and the motion sensors weren t supposed to act at the same time so there was no “interferences” problem, just needed for the receiver to know from which sensors it came from.

Any ideas ? (and sorry for the crappy english !).

2

You should be able to do that with the simple RF transmitters SparkFun sells.

http://www.sparkfun.com/products/10535

They don’t have channels or anything, so you would just need a very small micro with like 2 input pins like an ATTiny45 or something which would read from the motion sensor and send a number you assign and the motion sensor reading. Like if you have 15 sensors, you could use the same code for each and have them all send their own number with the reading. Then have your Uno read constantly. It’ll receive the number of the transmitter and the data from it, as many transmitters as you want.