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Basic question, troubleshooting — Parallax Forums

Basic question, troubleshooting

JimSalacainJimSalacain Posts: 4
edited 2007-05-11 15:40 in BASIC Stamp
Hi, I've been playinga around with BS2's wiring accelerometers using the board of education and now I want to assemble a circuit to luanch. Problem one is that the board of education is too big to launch so I'm trying to wire up a bare bones circuit with my own DB9 and the like. I have a BS2e and I followed the schematic for wiring it to the DB9. When I go to test it out, the MacBS2 software (which works fine on the board of education) does not find the BS2e. Well I'm basically stumped at this point. I need some ideas to tell me how to troubleshoot if I have a bad BS2e or a bad connection in the DB9.

Thanks...

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2007-05-03 03:21
    Can you post a schematic?
  • JimSalacainJimSalacain Posts: 4
    edited 2007-05-03 13:57
    Here's the overall schematic. In the interest of incrementally getting things working, I haven't wired up anything other than the DB9 stuff at the top.
    pdf
    pdf
    Telemetry Circuit rev 1.pdf
    60K
  • Mike GreenMike Green Posts: 23,101
    edited 2007-05-03 14:23
    1) The circuit itself looks OK. Make sure what you've wired up is what you've written down.

    2) I don't know how much current the accelerometers draw. If you're using a 9V radio battery, check to make sure it's not run down. They don't have a lot of capacity.
  • JimSalacainJimSalacain Posts: 4
    edited 2007-05-03 14:34
    I'll check on the wiring. Is there any voltage signature or anything I can look for off the BS2 with a voltmeter or an oscilloscope to tell me if its awake and waiting for a signal?
  • Mike GreenMike Green Posts: 23,101
    edited 2007-05-03 14:50
    I'm sure there are some signals on the BS2e substrate (like a clock), but they're not brought out to the pins. The PC resets the processor using the DTR line, then there's some handshaking over the serial line with the PC (Mac) initiating. You could try moving the BS2e back to the BOE to see if you can program it there. That would tell you that the Stamp is still fine.
  • JimSalacainJimSalacain Posts: 4
    edited 2007-05-11 14:38
    By way of brining closure to this thread, I got the DB9/BS2e working. The original DB9 schematic that I was using showed what appeared to be cross strapping of pins 2, 6 &7. In actuality, only 6&7 were to be cross strapped and 2 was to remain independent. When I fixed that it worked like a charm. Thanks for your help, Mike. Its nice to have a resource to go to when you're trying to work through what seems to be an intractable problem.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-05-11 15:40
    Jim,

    Remember, connect wires will have a dot to indicate they are connected. Not dot means no connection. Take care.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
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