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Basic stamp 2 module schematics without parts needed for programming? — Parallax Forums

Basic stamp 2 module schematics without parts needed for programming?

CuriousOneCuriousOne Posts: 931
edited 2012-11-27 13:13 in BASIC Stamp
Hello.

I want to do "mass production" of my built device, which uses basic stamp 2 module. The total number of modules I need for 1st time is 5 pieces, but it can grow in the future.

To reduce down the costs, my idea is as follows:

1. Buy Basic Stamp 2 oem module, assemble it.
2. Buy extra interpreter modules/eeprom from parallax, which will be inserted into above mentioned OEM module for programming.
3. Buy resonator and other parts for my needs.
4. Solder the programmed modules/eeprom into my device.

The question is, as I can see from basic stamp 2 oem module schematics, a lot of parts are needed only for programming. Considering the fact that I will be using already programmed chips in my end device, a lot of parts can be omitted. So, maybe anyone already has schematics of "bare" basic stamp 2 module? without programming circuit, power supply, etc?

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2012-11-25 08:27
    I haven't seen any such schematic. Basically, you'd leave out the two 10K resistor packs, the three transistors, and the two capacitors. Look at sections 5.1 and 5.2 of the PIC16C57C datasheet for a discussion about the connection to /MCLR and both power-on reset and brown-out detection. The OEM Stamp uses a MN13811 for this, but, depending on your needs, you might be able to leave this out or substitute something else as shown in the datasheet.

    You might want to leave access to the pins on the PIC16C57C needed for programming and make up an adapter consisting of the other parts needed for a programming adapter, perhaps leaving a header on the board. This would allow debugging of the finished device and the possibility of an upgrade in the field while allowing the soldering of the EEPROM to the board or the use of surface mount parts.
  • W9GFOW9GFO Posts: 4,010
    edited 2012-11-25 10:23
    Chris Savage has some nice minimalist Basic Stamp schematics here.
  • davejamesdavejames Posts: 4,047
    edited 2012-11-25 14:02
    ...wouldn't the only thing to program be the EEPROM?

    Unless I've missed something, all pertinent data is stored only in there.
  • Mike GreenMike Green Posts: 23,101
    edited 2012-11-25 14:30
    Yes, everything about the PBasic program is stored in the EEPROM. That's the only thing that has to be "programmed". Attempting to program the PIC16C57C will destroy the pre-programmed interpreter. The Stamp interpreter provides a nice EEPROM programmer for either program or data. You could use an external EEPROM programmer to copy the program into loose chips, then mount them on your board. That will probably be faster and may fit into an automated assembly flow for mass production, but the built-in EEPROM programmer sure is convenient.
  • CuriousOneCuriousOne Posts: 931
    edited 2012-11-26 20:19
    Thanks. I do not know that only eprom is programmed, thought PIC is also programmed.

    Regarding the brown out detection. Do I really need it? My circuit will have separate power controller, so there will be 5 volts always, or no power at all. Do I still need brownout thing?
  • Mike GreenMike Green Posts: 23,101
    edited 2012-11-26 20:59
    Read Chris Savage's webpage (post #3). He discusses several options and issues around brown-out detectors. You'll have to decide for yourself whether you need one.
  • CuriousOneCuriousOne Posts: 931
    edited 2012-11-27 13:01
    Yes, I have read it. As I said, my power simply won't fall below 5v - at 4.99v it will be switched off. Also, my program does not writes anything to EEPROM while being executed, will it corrupt anyways?
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2012-11-27 13:13
    If you don't expect the supply to linger below the operating voltages of the chips then you shouldn't need the brownout detector. A battery powered design would be another story.
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