as a beginner or less, I was looking in tutorials sitesI don´t know where you read that, but I don´t really think that´s true. The practical distance depends on the sensitivity of the receiver and reflections in the room.
I was planning to deal with each transmitter as if it transmits alone, then later in a " Reader " program, I will place them depending on how far they were from the 3 receivers.You definitely need some kind of receiver in the transmitters, because you need to get some kind of synchronisation between them, to make them all send at the same time.
You could use infrared light instead of RF for the trigger, but that will again introduce risk of blocking the sensor and not firing when it should.
that was my idea when I thought of using the same frequency anyway.
For making them send at the same time, I was thinking of using one chip of 555 which is connected to them, don't you agree?
as you explained, Infrared is useless in our case.
I'll try that indeed.If you want to give this a try, make two ultrasound transmitters, each generating some kind of tone, and try to receive it with one receiver. To keep it simple, connect the transmitter by wires, place them at a typical distance from the receiver, and start trying to distinguish which one came first, and the exact times of arrival for each one.
But you have to excuse me,
What did you mean by " kind of tone " ?
I don't understand how can I tell which tone is belong to which transmitter?
BTW: Is there any quick yet perfect explanation about encoding/decoding Subject, and how can it be done?
I've looked everywhere!
thanks a lot.