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Puzzling BS2 Module Problem — Parallax Forums

Puzzling BS2 Module Problem

EschattEschatt Posts: 16
edited 2009-01-05 03:49 in BASIC Stamp
Hi,
I have been working on several projects with my BS2 until recently, it stopped working all of the sudden. When I now connect the BS2 using a serial to usb cable (that works with my BS1) on the board of education, the computer can no longer identify it. I have gone through all of the troubleshooting points that parallax posts on their website with no luck. Nothing appears/smells to have burnt out and the connections all seem solid. Does anyone know of any other forum(s) that look at this problem? Has anyone else run into this issue? And lastly does anyone have any tips on how to get my BS2 working again? Thanks in advance!
-Eschatt

Comments

  • Beau SchwabeBeau Schwabe Posts: 6,568
    edited 2009-01-04 05:31
    Eschatt,

    I know this is a silly question, but I'm even guilty of this one... have you checked your battery?
    When·you do a Run-->Identify, do you get a Loopback indication?

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    Beau Schwabe

    IC Layout Engineer
    Parallax, Inc.
  • EschattEschatt Posts: 16
    edited 2009-01-04 05:41
    Beau Schwabe,
    I have tried multiple power supplies, the board says that it is rated for 6-30VDC, one power supply is 12VDC and the other 18VDC. And yes I get a Loopback and Echo indication.
    -Eschatt
  • Beau SchwabeBeau Schwabe Posts: 6,568
    edited 2009-01-04 06:22
    So, the BS1 still works with the serial to usb cable but the BS2 does not?

    Can you measure the voltage on the BS2 on pins 24 (VIN) and pin 21 (VDD) with respect to VSS (<-- Pin 23 or pin 4)

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    Beau Schwabe

    IC Layout Engineer
    Parallax, Inc.
  • EschattEschatt Posts: 16
    edited 2009-01-04 16:01
    The voltages between pins 24(VIN) and pin 21(VDD) in respect to VSS are 4.03V and 4.44V respectively.
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2009-01-04 16:19
    VIN , with respect to VSS, should be (needs to be) greater than VDD.··VIN is your input voltage, whether it's 4.03 or 4.44V it's low.· VDD, with respect to VSS, should be +5.
  • EschattEschatt Posts: 16
    edited 2009-01-04 16:38
    What should I do in order to increase the voltages of the VIN and VDD pins?
  • Beau SchwabeBeau Schwabe Posts: 6,568
    edited 2009-01-04 17:26
    Eschatt,

    The VIN should read the same voltage level as your power supply,·at least·6·Volts or more.
    The VDD should be right at 5 Volts, indicating that the internal voltage regulator on the BS2 is working properly.

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    Beau Schwabe

    IC Layout Engineer
    Parallax, Inc.
  • MovieMakerMovieMaker Posts: 502
    edited 2009-01-04 18:19
    make sure the stamp is not in there backwards, pins bent, pins out of socket not aligned properly. (stupid answer, but maybe)
  • EschattEschatt Posts: 16
    edited 2009-01-04 18:44
    It looks like the problem might be the Voltage Regulator on the Super Carrier Board, it is taking the 18VDC from the power supply and reducing it to 4.44V. Is this a problem that is caused just by the Voltage Reg. or could it also be involved with the capacitors and other parts of the power supply circuit?
  • EschattEschatt Posts: 16
    edited 2009-01-04 18:52
    Would the BS2 work theoretically, if I replace the faulty 8V regulator, with a new 12V Voltage Regulator?
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2009-01-04 18:55
    Anything getting hot?
  • EschattEschatt Posts: 16
    edited 2009-01-04 19:04
    The Regulator had been hot in the past but is no longer hot now when it is plugged into the power source.
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2009-01-04 19:16
    When you started the Subject, you stated that you were working with a Board_of_Education and just a couple of posts back you said it's a Super_Carrier.

    The Super_Carrier's regulator is 5V and, according to the schematic I'm looking at, it provides VDD for the Stamp.· The Stamp's VIN is not connected.
    The RevC BoE, on the other hand,·takes VIN for the Stamp's own on-board regulator, but the Stamp's VDD is not connected to the BoE's VDD (they're separate.)

    So, what board are you using?·
  • FranklinFranklin Posts: 4,747
    edited 2009-01-04 19:37
    Also if the stamp is on a board I would remove it while you are trying to work on this problem. Better to have a bad board than a bad board and a destroyed stamp.

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    - Stephen
  • EschattEschatt Posts: 16
    edited 2009-01-04 20:10
    Thanks for the advice Franklin. PJ Allen- Sorry for the confusion, I got mixed up because while in school I work with the BOE, I work with the Super Carrier Board at home, I am using the Supper Carrier Board now. My apologies on the mix up.
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2009-01-04 20:52
    OK, well, in any event, looks like you have to troubleshoot that VR1 (LM2940_5.0) circuit.· Since VR_1 supplies the BS2's V_DD, you don't want any more than +5V, therefore a 7808 or 7812 "replacement" is NOT acceptable.· Here's a link for the Super_Carrier board schematic.
    ·
  • EschattEschatt Posts: 16
    edited 2009-01-05 03:49
    ok, I am going to working on figuring out what has gone wrong with the VR1. Thanks for helping me identify the problem.
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