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Basic Stamp General Questions — Parallax Forums

Basic Stamp General Questions

MRMR Posts: 46
edited 2007-11-24 13:50 in BASIC Stamp
Hello,

I would like to personally thank Mike Green For all of his help over the last couple of weeks.


1. I have designed a successful circuit using the basic stamp and a very large solder-less bread board. Now I have designed a printed circuit board complete with sockets to wire everything up. How should I connect voltage? Should I use the VDD pin wired in parallel with the main voltage bus? Or Should I use VIN pin? Is it okay to wire either of these pins into the main voltage bus? I have not wired any power or ground connections in series, every power or ground is wired in parallel.

2. Is there any internal command i.e. PBASIC code, that can tell the stamp to reset it self? I need a way to reset the stamp automatically.

3. When multiplexing the displays from another project, I can still see flicker, is there anyway to attach an external clock to eliminate this flicker?

4. How do I determine the duty cycle for each display, i.e. how long it has to stay on to be bright enough without flicker? Will they all have the same amount of time?

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2007-11-24 13:50
    1) What is your main voltage bus? Does it supply regulated 5V? Does it supply something else? What do you mean "power or ground connections in series"? The Stamp's Vdd pin is normally wired to a regulated +5V supply if one is available in which case Vin is not used. The Stamp's Vin pin is normally wired to an unregulated supply line (at least 6V and less than 9V usually) in which case Vdd is the output of the Stamp's own regulator (and can supply maybe 30-40ma at most).

    2) There is no reset command although there is not much to reset. It's easy to reinitialize OUTS and DIRS and goto the beginning of your program. The call stack wraps around, so the current contents can just be discarded, and there are only a few variables to reinitialize.

    3) No way to tell without more information from you (like schematics, code if applicable)

    4) Generally a repetition rate of 25 to 30 times a second will be fast enough for persistence of vision. The on time needed will depend on the current and the efficiency of the diodes. Best thing to do is experiment. The LEDs don't all have to have the same on-time, but they'll probably appear with different brightness. It depends.
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