HEy we have designed our own 8051 board using 4066 to convert single serial port to 4 port but gives lots of garbage once we power up
thanks for your reply, all control signal(analog switch 4066) are on P2 port whcih has internal pull up. the signals for unused signal are grounded
Is there a reason that you have an analog switch for multiplexing one-way digital signals?
Is there pull-up/pull-down resistors on the signals - what happens with the signals for the unused serial ports when you mux to another port - does the signals float or are they forced to a good logic state?
Design is not with me its with my boss.... I am working on this. Its simple rx and tx pin of 8051 is connected to 4066 and from 4066 to max232, data is sent to outside world by selecteing control signal to which are connected between 8051 and 4066 It works fine with all serial device except serial device (like printer)
Cool. Are you offering to share the design?
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