I am designing a game that requires three players to wirelessly signal a central unit whether their ‘buzz in with the answer’ button is pushed. Think Wireless Jeopardy. I had great success modifying Radio Shack wireless doorbells because they have three different channels with three different carrier frequencies. Unfortunately, when two players ‘buzz in’ nearly simultaneously, the signals interfere with each other and I can’t properly detect them. I also tried using commercial TV infrared controllers and receivers but, if two players buzz in nearly simultaneously, the signals again interfere and the receiver gets confused. I tried using a Holtek encoder-decoder scheme but, again, if two players buzz in nearly simultaneously, the signals interfere. Any suggestions on how to manage these data collision problems?
Jeff Schwartz
I think those Holtek class encoders use duplicate transmission and a long data preamble and so forth such that they can’t do what you want to do, that being like 0.1 second resolution - leading to a message duration of far less that 0.1 second.
Not cheap: do it with Digi XBee series 1 modules. But they’re an overkill, however, simple. No microprocessor, use their I/O bit replication wirelessly, different bit for each player, perhaps different radio for each player, one central. Or one radio for n players, with a wire from each player to the nth digital I/O bit. Maybe you want handheld for each player though.
So another might be the Hope RF modules. They are sophisticated and packet based, fast, and really cheap.
http://www.hoperf.com/rf_fsk/rf_transmitter.htm
I don’t think SFE here sells these, but rather SFE has only older produts from them
Or Lynx LR Series Wireless
If you want to register different button presses, a Lynx LS Series encoder/decoder setup would work well in tandem with those radios