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Communication with the AeroComm Link (RS232) — Parallax Forums

Communication with the AeroComm Link (RS232)

jcrmjcrm Posts: 5
edited 2007-09-07 12:45 in Propeller 1
Hi guys,
Congrats on the 20 years! I´m new at this and I have a question. I need to connect the propeller with the Aerocomm ConnexLink (RS232). Can I use the circuit shown in the figure in the attachment or do I have to make some type of modification?

Thanks,
Juan Ramirez
diagrama.JPG
503 x 349 - 18K

Comments

  • deSilvadeSilva Posts: 2,967
    edited 2007-09-06 17:14
    Whatever that device you are talking about ever be, this is not the best possible interface to it.

    (1) By all means leave out the reset-connection!

    (2) The 4,7k resistor would function as a "pull-down" to something as -12V so far as it is available on the DTR pin. This is usual but not mandatory. Your voltage swing for sending from the prop wil be -12 <-> +3 V

    (3) Either your device will accept 0 <-> 5V, then you do not need -12 V or it will have a standard -12 <-> +12 V voltage, in that case you should protect the transistor basis against the incoming -12 V using a diode e.g..


    I know a MAX 233 chip costs around $5 but it will relieve you from any further considerations without any additional part at all.
  • LeonLeon Posts: 7,620
    edited 2007-09-06 17:16
    You might need true RS-232 levels, especially if you don't have the DTR signal available on a PC serial port to give you a negative supply.

    Leon

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Amateur radio callsign: G1HSM
    Suzuki SV1000S motorcycle

    Post Edited (Leon) : 9/6/2007 5:21:49 PM GMT
  • Paul BakerPaul Baker Posts: 6,351
    edited 2007-09-06 17:23
    Juan what is your intent with the Aerocomm, to provide a wireless serial link, or to program the Propeller?

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    Paul Baker
    Propeller Applications Engineer

    Parallax, Inc.
  • jcrmjcrm Posts: 5
    edited 2007-09-06 21:36
    Thanks DeSilva ,Leon and Paul
    I need one wireless serial link propeller and AeroComm ConnexLink

    Amateur radio callsign: YV3FHR
  • Paul BakerPaul Baker Posts: 6,351
    edited 2007-09-06 21:47
    In that case DTR isn't needed.

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    Paul Baker
    Propeller Applications Engineer

    Parallax, Inc.
  • jcrmjcrm Posts: 5
    edited 2007-09-06 22:41
    Thanks again Paul

    Juan Ramirez
    Amateur radio callsign: YV3FHR
  • ALIBEALIBE Posts: 299
    edited 2007-09-07 12:45
    i have been interfacing Propeller w/ Aerocomm AC4790 R/Tx for my robot project.· Purely for communication btwn the robot and the homebase.·

    http://aliben.wordpress.com/2006/10/24/interfacing-aerocomm-ac4790-with-propeller-chip/
    http://aliben.wordpress.com/2006/10/26/testing-the-ac4790-and-propeller-interface-w-alibe-homebase-command-center/
    http://aliben.wordpress.com/2006/10/24/aerocomm-ac4790-a-short-introduction/



    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    "any small object, accidentally dropped, goes and hides behind a larger object."

    ·
    ALIBE - Artificial LIfe BEing. In search of building autonoumous land robot
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