Whichever you pick, the idea is simple. Say you have 8 of them; just put them on a Port like PORTB, and transmit the whole portb via RF. That is all.

Then, your byte being transmitted will look like 00000111 as you know, and 1s will be the ones under detect, 0s not yet detected.

I suggest PIR modules as complete unit. There are cheap ones at around US$5.00. You provide supply voltage (usually 110/220V) and you get a relay On/Off output. Connect the relay outputs directly to your pic pins. When the relay is ON, the pin will be pulled low, when Off the pin will be pulled high by a resistor or internal weak pull up etc.

Should be easy to implement.

Rx part is also easy. Put leds on say PORTB again. Drive the whole port by incoming byte from RF module. That is all.

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