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How to power the BS2 Rev G chip? — Parallax Forums

How to power the BS2 Rev G chip?

thangngocthangngoc Posts: 23
edited 2010-01-27 19:00 in BASIC Stamp
Hi I am basic stamp beginner. Instead of using the Basic Stamp Homeword Board, I want to construct the BS2 Rev G chip within the breadboard for testing the servo. I have already built a 5V power supply in order to power the chip and run the the servo. However, I don't know the wiring from my 5V regulated voltage to power the chip? Which pin should be connected? Thanks in advance!

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2010-01-22 18:28
    If you haven't looked at it already, you need to look at the schematics in the BASIC Stamp Syntax and Reference Manual. This is included in the help files of the Stamp Editor as well as being downloadable from Parallax's website (through the Downloads page under BASIC Stamp Documentation). There are also diagrams of the Stamp modules showing the pinout. Page 12 shows that Vdd is pin 5. This is either the output of the Stamp module's own regulator (if you use an unregulated power source to Vin) or the input for a regulated 5V power supply. You also need to be sure that Vss is connected to the ground end of your power source (in either case).
  • thangngocthangngoc Posts: 23
    edited 2010-01-22 18:44
    you said Vdd is pin 5, i think this is for BS1 module. Iam using BS2 Rev G and its Vdd is pin 22 as shown in the schemetic www.interaccess.org/workshops/downloads/microcontroller_workshop.pdf
    So you meant that I have 2 options to power the chip: one from the Vin(+5.5V to +15V) and one from Vdd (+5V regulated).
    Let me try and report it back. Thanks
  • Mike GreenMike Green Posts: 23,101
    edited 2010-01-22 18:52
    I'm sorry. You're absolutely right about the pin number.

    You do have the two options for powering the chip. As long as you have a common Vss (ground), you can use either the unregulated input (Vin) or the regulated 5V (Vdd) from your regulator. If you're just experimenting with the Stamp, it may be easier to use the unregulated input. If you've got a lot of external circuitry and motors hanging off the BS2, you'd want to power that from your own regulator since the on-module regulator is limited in its output current.
  • thangngocthangngoc Posts: 23
    edited 2010-01-22 19:49
    ok, thanks Mike!! my servo worked perfectly when I tried to power the BS2 chip using unregulated input (which is 6.2+V). However, when I tried to use my own 5+V regulated voltage, the servo seemed not to function right as it should.
    Another question, I have the four leg pressed button , and how do I connect the RESET (which is pin 22) if I want to reset the servo instead of unplugging and plugging the the power?
  • thangngocthangngoc Posts: 23
    edited 2010-01-27 18:41
    Mike Green said...
    I'm sorry. You're absolutely right about the pin number.

    You do have the two options for powering the chip. As long as you have a common Vss (ground), you can use either the unregulated input (Vin) or the regulated 5V (Vdd) from your regulator. If you're just experimenting with the Stamp, it may be easier to use the unregulated input. If you've got a lot of external circuitry and motors hanging off the BS2, you'd want to power that from your own regulator since the on-module regulator is limited in its output current.

    So do you know how much is output the current is limited in the BS2 on-module regulator (Pin Vdd)?

    Post Edited (thangngoc) : 1/27/2010 7:00:49 PM GMT
  • JDJD Posts: 570
    edited 2010-01-27 19:00
    Thangngoc,

    The rating for the BS2 on-board regulator is ~50mA.

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    Respectfully,


    Joshua Donelson
    www.parallax.com
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