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Help please :( BS2sx to control a projector — Parallax Forums

Help please :( BS2sx to control a projector

Walts_WorkerWalts_Worker Posts: 5
edited 2005-12-29 20:38 in BASIC Stamp
Hello!· I'm having problems with hooking up my BS2sx to control a projector(Sharp PG-A20X).· All I need to do is to tell it to turn off and on via the projectors 'command set.'· I can download the program to the Stamp and that's fine.· I can hookup the projector to my pc and it works via hyperterminal... But when I connect the stamp to the projector, it doesn't seem to work· confused.gif· I've tried using a straight through RS 232 and then a 'switched' Rx & Tx lines but nothing seems to work.· I'm using SEROUT command and using the SOUT & SIN 'programming connections' [noparse][[/noparse]Pin 1 & Pin 2].· Do I need a 1488 & 1489?

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I am different, I knew that long ago.· I give everyone the trust and respect that's due to them as a human and possible friend.· They build or tear away at that by what they say and do.

Night`Wolf :--)

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2005-12-29 20:14
    Hello,

    ·· You may need to use I/O lines and a MAX232 to talk to the device.· The SOUT and SIN lines are designed for communication with the host PC, and to some degree get part of their signal from the host PC.· This may not be available from the device you're talking to.

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • allanlane5allanlane5 Posts: 3,815
    edited 2005-12-29 20:16
    If the project works hooked up to your PC, then you'll probably need to 'switch' pins 2 and 3 to get the BOE to control it.

    Then, the BS2's RS-232 circuitry on SOUT and SIN modulates the RX voltage to make its TX signal. This means anything sent from the projector to the BS2 will immediately be echoed back to the projector. I don't know if this is a problem in your situation.

    The quick and easy solution is to add a MAX232 chip with 4 capacitors so you have true RS232 signaling levels. www.kronosrobotics.com sells a nice small adapter board for this purpose. (This serves the purpose of the 1488 and 1489 chips you call out, but in a single chip, with only +5 and ground required).
  • steve_bsteve_b Posts: 1,563
    edited 2005-12-29 20:28
    Do you know the pinout of your projector?
    Some of those silly manufactures like to change the pinouts around so that you have to buy "their" special cable to get it to work!

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    ·

    Steve

    "Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."
  • Walts_WorkerWalts_Worker Posts: 5
    edited 2005-12-29 20:38
    Thanks Chris!
    allanlane 5: Yes, I'm wondering that too as it may think I'm trying to send commands to it and doesn't know how to interpit them. And yes, I've looked at that MAX232 and would probably use it, though I'm more familar with the 1488 & 1489[noparse]:)[/noparse]

    steve_b: THe projector has it's own connector -- From a 9 pin Mini DIN male(Circular) on one end and on the other is a 9 pin D-Sub male which is from Sharp(AN-A1RS).
    Pinout: Mini DIN D-Sub
    1 NC NC = Not Connnected
    2 Rx Rx =Receive Data
    3 Tx Tx = Transmit Data
    5 SG SG = Signal Ground
    All others are not connected.

    Thank you all for all your help!

    RandyT A.K.A. "Walt's Worker"

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    I am different, I knew that long ago.· I give everyone the trust and respect that's due to them as a human and possible friend.· They build or tear away at that by what they say and do.

    Night`Wolf :--)
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