Can I use volmeter to measure voltage of signal at 9600 baud rate?

Discussion in 'Embedded Systems and Microcontrollers' started by anhnha, Apr 29, 2012.

  1. anhnha

    Thread Starter Well-Known Member

    Apr 19, 2012
    I want to check data is sent through comm port without oscilloscope.Now i only have voltmeter.How can i measure the voltage is in TX and RX of comm port at 9600 bps?
  2. praondevou

    AAC Fanatic!

    Jul 9, 2011
    A voltmeter won't tell you much about the quality of the signal, High/Low voltage levels or what data exactly is being sent/received. At most it will tell you if something IS happening or not.
    You need an oscilloscope, logic analyzer or just plug it into your PCs 232 port and monitor what is happening on the bus via hyperterminal or other serial bus monitoring software.
  3. bertus


    Apr 5, 2008
  4. anhnha

    Thread Starter Well-Known Member

    Apr 19, 2012
    Thanks for all help.
    I used voltmeter to measure the logic level when signal is transmit through TX but i think that it vary too fast therefore the voltmeter is can keep change.
    You are right possible i have check it in oscilloscope.
  5. panic mode

    Senior Member

    Oct 10, 2011
    sure you can but reading will be meaningless :p

    you can use diode and capacitor to get peak (either positive or negative) which is just about the only thing doable with conventional multimeter.

    scope is one useful piece of equipment... 9600 bps can be "scoped" with sound card (it will not look very rectangular, for that you need faster sampling rate).