mailboy1983 Posted February 7, 2004 Report Share Posted February 7, 2004 hi, im doing an electronics&comm project as part of my curriculum. im thinking of an announcer system to be placed in bus stations which receives a particular code transmitted from a bus and announces to the passengers about its arrival. Is RF is a good choice 4 transmission ??RF has better coverage than IR doesnt it? also there r 2 ways i thought 4 code tranmission 1)DTMF signals - is simple but only few capabilities (no: of buses) :-\2)Digital transmission-of course more complex,also needing a uC but anyway im planning to implement it without a PC by using a uC :-\ so have any of u got anything that could help me out ??? bye!! Quote Link to comment Share on other sites More sharing options...
MP Posted February 8, 2004 Report Share Posted February 8, 2004 There is a project in the project section of this site for a laser transciever. It might be a good building block. You can use a microprocessor to send the signal.MP Quote Link to comment Share on other sites More sharing options...
russlk Posted February 8, 2004 Report Share Posted February 8, 2004 IR is subject to interference due to fog, dust and snow, so RF would be more reliable. I assume the message is pre-recorded, so the bus only has to identify itself. DTMF would be simple. Quote Link to comment Share on other sites More sharing options...
mailboy1983 Posted February 10, 2004 Author Report Share Posted February 10, 2004 thnx 4 the repliesi already thought of using RF but the big problem comes when u have to identify more than one buses coming to the station u have to decide whether buses will transmit same frequencies or different ones and abt interfernce b/w signals ::)and if ure having multiple frequencies then receiver has to check all frequencies automatically . also once announced theres no need to announce the same bus again. now these r some of the problems which ive encountered with this project now wht should i do??? ::) Quote Link to comment Share on other sites More sharing options...
russlk Posted February 13, 2004 Report Share Posted February 13, 2004 The RF is just the carrier, the DTMF tones will all ride on it. The receiver will seperate the tones using filters, each one identifying a bus. simple tones could be used because the probability of interference is low and signal to noise will be high. Quote Link to comment Share on other sites More sharing options...
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