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USB to RS232 adapter

Discussion in 'General Electronics Discussion' started by HellasTechn, Oct 3, 2016.

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  1. HellasTechn

    HellasTechn

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    Apr 14, 2013
    Hello there friends !

    I have this issue lately with RS232 and modern laptops that do not have a such port. Because i use Picaxe microcontrollers and other devices like GPS receivers i need a serial port that can transmit and receive rs232 data.
    I bought this cheap chineese cable
    http://www.ebay.com/itm/272205577365?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
    and ofcourse it does not work. Not to mention that it's driver only works on windos Xp which is not really the problem for me since i have an old laptop dedicated to such work. This cable bives me a noise like negative signal on both pins 2 and 3 (pin 5 referenced) and most of the times (useing termite software) may transmit a line or two and then freeze.

    So, any suggestions about a decent and cheap (anything around 10 bucks) converter ?

    Thank you !
     
  2. Bluejets

    Bluejets

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    Oct 5, 2014
    Last edited: Oct 3, 2016
  3. HellasTechn

    HellasTechn

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    Apr 14, 2013
    The last one looks interresting. I guess the rs232 DB9 connector is wired as shown in the picture.
    DTR to DTR, RXD to RXD, TXD to TXD and GND to GND.

    I dot understand what the 5V and 3.3V pins are for.
     

    Attached Files:

  4. Bluejets

    Bluejets

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    Oct 5, 2014
    You pick which supply you want to drive the micro with.
    In the case of Arduino, either 3.3v or 5v.

    Of course, if you supply the micro via an external supply, then do not use either of these.
    This is for stand-alone programming.

    Obviously with the common ground connection as well.
    Tx Rx swap over...i.e. one transmits, the other end receives.
     

    Attached Files:

    Last edited: Oct 4, 2016
  5. HellasTechn

    HellasTechn

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    Apr 14, 2013
    So if i got that right the 3.3V and 5V pins are to supply any microcontroller connected to it, Yes ?
    But if i do not wish to use it with a microcontroler ? If for example i want to feed USB port of a PC with RS232 data through the converter ? will i not be able to do that ?


    About the TXD and RXD pins i think that it is clear. TXD pin gives out rs232 data from the usb port to the rs232 device and RXD gives the rs232 data from the rs232 device to the USB port.
    isnt that right ?
     
    Last edited: Oct 4, 2016
  6. Bluejets

    Bluejets

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    Oct 5, 2014
    I've always used in conjunction with a micro but yes, seems correct otherwise. When connected to the pc , assuming drivers are installed, you should see it come up as a particular com port, seems to vary so best to check in "hardware" for the correct allocation.
     
  7. Kiwi

    Kiwi

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    Jan 28, 2013
    We use Digitus DA-70156 USB to serial converters at work. They seem to work well on the newer laptops that don't have serial ports.
     
  8. HellasTechn

    HellasTechn

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    Apr 14, 2013
    Any idea where can i find the windows 7 or XP driver ?

    Thanks ! a little out of my budget though. :)
     
  9. HellasTechn

    HellasTechn

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    Apr 14, 2013
    By the way nice Mustang Kiwi.
    I used to drive the 1997 model with the 3.6L engine. I had to sell it when i got back home.
     
  10. HellasTechn

    HellasTechn

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    Apr 14, 2013
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