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USB, Basic Stamp

oberocoberoc Posts: 7
edited 2005-11-01 15:25 in BASIC Stamp
Hi All,

I just started to play with my basic stamp this morning, and I am running into difficulties. I have the Board of Education USB board and the BS2 chip.

What I have done so far:
Seated the chip according to the diagram in the book
Hooked up the power to the board
Hooked the Board up to my machine via USB cable
Loaded in the drivers for the USB - serial connection
fired up my Basic Stamp Editor
Tested the connection: Run -> Identify

The Board responds on COM4 and gives a YES to loopback and echo, but no device type!

I have set the latency down in the port settings to 1 in the device manager, but no dice.
Anything else I could try?

-Tino

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2005-10-31 15:58
    Hello,

    ·· I believe this issue was solved via phone this morning.

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • Helen CHelen C Posts: 34
    edited 2005-10-31 18:41
    What was the problem?· I am experiencing similar problems with a BS2OEM and FT232BM as per the USBBOE board schematic.· If I put a MAX 232 between the FT232BM and the BS2 then all is fine but if I use the transistors as·shown in the USBBOE schematic the BS2 cannot be reset or reprogrammed but other than that the dubug port works ok.· Any suggestions please?

    Thanks

    Helen

    PS Just put a scope on the ATN line and tried the Identify button and what do you know it worked!· Is this down to stray capacitance?·


    Post Edited (Helen C) : 10/31/2005 6:54:55 PM GMT
  • oberocoberoc Posts: 7
    edited 2005-10-31 19:13
    Something really simply, turn on the power strip! [noparse]:)[/noparse]
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2005-10-31 19:26
    Helen,

    ·· It sounds like you have redundant circuitry.· By default the OEM Stamp Module is setup to communicate to an RS-232 level serial device.· If you're trying to emulate the USB BOE connections, then you don't need the transistors on the OEM BS2, depending on how you have it wired.

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2005-10-31 19:35
    Oh, and don't forget the transistors on the output of the FT232BM chip are tied to Vusb, not Vdd.

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • Helen CHelen C Posts: 34
    edited 2005-11-01 09:58
    Thanks for the replies.

    I am powering the FT232 from a 5V reg so not Vusb.

    I realise that I can take the TX and RX lines from the FT232 directly to the OEM Stamp chip but I am having trouble making the ATN line work properly in this way.· This is why I built the OEM as per the BS2OEM schematic then put in the USBBOE parts as well.

    Obviously, I want to minimise the amount of circuitry required.· So I would be grateful for hints on how to make the ATN line function correctly without converting it from TTL to RS232 and back again.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2005-11-01 14:47
    Do you have capacitors on the Attn line?

    If you search the Forum, yu will find that they eliminate some headaches. I don't have the schematic handy to mention values, but I do know a direct connection sometimes causes trouble.

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    "When all think alike, no one is thinking very much.' - Walter Lippmann (1889-1974)

    ······································································ Warm regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2005-11-01 15:25
    Helen,

    ·· Given what you're trying to do, it might have been better to follow the Schematic for the USB BOE.

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
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