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reset line to Interpreter Chip in BS1 — Parallax Forums

reset line to Interpreter Chip in BS1

Steve JoblinSteve Joblin Posts: 784
edited 2007-01-19 18:08 in BASIC Stamp
Trying to "roll my own" BS1 (no worries... all components were purchased through Parallax!)...

I think I have it all wired correctly, but I keep getting "No Basic Stamps Found"...

I think the issue maybe the way I have pin number 4 (the Reset pin) hooked up... I don't have the brownout circuit... should the pin be connected to +5V via a 4.7k resitor and to ground via a momentary switch?· does this does not seem correct... how should it be set up if I am not using a brownout circuit?

attachment.php?attachmentid=45058

Also, just want to confirm·that I should be using the same serial cable that I use to program a BS2... correct?· I just plug in the BS1 Serial Adapter to the cable and then to my three pin header... correct?

I am running the latest version of the Editor (version 2.2) and have ' {$Stamp BS1} and ' {$PBASIC 1.0} declarations at the start of my test program.

Any ideas are welcome!!!!

Post Edited (Steve Joblin) : 1/17/2007 10:00:53 PM GMT
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Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-01-18 16:36
    Steve,

    Which schematic are you building from? It appears there may be a few errors in the BS1-OEM Schematic. The brownout detector does not need to be connected to function. All it does is pull the /RESET line LOW when the voltage drops below the trigger point. Otherwise your wiring of that line appears to be correct.

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    Chris Savage
    Parallax Tech Support
  • Steve JoblinSteve Joblin Posts: 784
    edited 2007-01-18 17:10
    Oh no! Yes, I am using the attached (that I got by typing in "BS1 Schematic" on the Google Search box from the Parallax site... what errors are there?

    I modifed it slightly to eliminate the header and brownout... what changes do I need to make?

    attachment.php?attachmentid=45077

    Post Edited (Steve Joblin) : 1/18/2007 5:28:42 PM GMT
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    BS1Oem.pdf
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  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-01-18 17:48
    Steve,

    Sorry…I went back and double-checked and your schematic is okay…A few things were moved around but it does look fine. Of course, the mail filtering capacitor isn’t there, so depending on your power supply you could be experiencing noise in your circuit. Do you have a BSLA or a scope?

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    Chris Savage
    Parallax Tech Support
  • Steve JoblinSteve Joblin Posts: 784
    edited 2007-01-18 17:59
    Mail Filtering Capacitor? What is that?

    My power supply is based on the LM2940-5.0V with appropriate filter caps on both the input and output... One thing that I noticed this morning is that I don't know if pin 14 on the Interpeter is hooked to Vdd... I'll check when I get home to see if that is my "Stupid mistake" (I hope is it something as simple as that!)... I'll check everything again and let you know...

    I don't have a scope... saving up for the Parallax O'scope... my research has indicated that it is the best value out there and I am looking forward to learning the "Understanding Signals" curriculum!
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-01-18 18:09
    Steve,

    The filter capacitor is shown in the schematic, but you removed that portion of the schematic from what you built so I didn’t know if you still added it. It is a 10uF capacitor. The scope would allow you to monitor activity on the PCI/PCO lines which could aid in troubleshooting. In any event, recheck your wiring and we’ll go from there. Take care.

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    Chris Savage
    Parallax Tech Support
  • Steve JoblinSteve Joblin Posts: 784
    edited 2007-01-18 18:34
    hmmmm.... I am using a 22uF polarized electrolytic cap... is that o.k.?

    attachment.php?attachmentid=45078

    Post Edited (Steve Joblin) : 1/18/2007 6:41:07 PM GMT
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  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-01-18 23:25
    Yes, that should be fine...Did you check your pin (the one you thought wasn't connected)?

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    Chris Savage
    Parallax Tech Support
  • Steve JoblinSteve Joblin Posts: 784
    edited 2007-01-19 01:08
    just went through it all again... everything looks good... I guess I need to buy a new PIC and EEPROM to confirm that either is not damaged... my wiring and solder joints all look good and are identical to the above schematic... don't know what else to try?
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-01-19 06:04
    Steve,

    When you say PIC, you are using the preprogrammed interpreter chip from us correct? A blank PIC will not work as it has no BASIC Stamp firmware on it.

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    Chris Savage
    Parallax Tech Support
  • Steve JoblinSteve Joblin Posts: 784
    edited 2007-01-19 12:19
    Ha! I was just in the shower wondering if I would get any additional insights, and thought "I wonder if they thought in my post that I meant the BS1 Pre-Programmed Interpreter Chip?... better make a revision to my post to clarify!"

    Placed my order for:
    - 256-byte EEPROM (BASIC Stamp 1-DIP), Product ID: 602-00005
    - 4 MHz resonator, Product ID: 250-04050
    - BASIC Stamp 1 Interpreter Chip (DIP), Product ID: PBASIC1/P

    Just want to confirm that the cable I am using between my laptop serial port and the BS1 Serial Adapter is the same cable that I use to program my BS2... correct?

    Also, all the resistors should be 4.7k ohm... correct?

    Post Edited (Steve Joblin) : 1/19/2007 1:48:32 PM GMT
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-01-19 15:51
    Steve,

    Actually all resistor values are 10K, not 4.7K. Take care.

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    Chris Savage
    Parallax Tech Support
  • Steve JoblinSteve Joblin Posts: 784
    edited 2007-01-19 18:04
    Now I am really confused... The schematic taken directly from the Basic Stamp Reference Manual (v2.2) shows 4.7k... is it that the DIP versions use 10k and the SMD versions use 4.7k?

    Could the difference be the cause of it not working?



    attachment.php?attachmentid=45085
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  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-01-19 18:08
    Steve,

    That is correct, the through hole version uses 10K while the SMT uses 4.7K. Also be aware…I believe the pin outs are different between the surface mount and through hole interpreter chips. Take care.

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    Chris Savage
    Parallax Tech Support
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