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PS questions for a BS1 — Parallax Forums

PS questions for a BS1

Buck RogersBuck Rogers Posts: 2,187
edited 2010-09-11 14:25 in BASIC Stamp

Hello!
About BS1, I saw this described on the PDF of the FAQ that I have here:

"What is the VIN pin used for?
The VIN (Voltage Input) pin is used to power the BASIC Stamp from a 6 to 15 volt source. The VIN pin is
the positive connection while the VSS pin is the negative, or ground, connection. When powered from the
VIN pin the BASIC Stamp regulates the voltage down and outputs +5 volts on the VDD pin.
How does the VDD pin work?
The VDD pin (+5V) outputs 5 volts when the BASIC Stamp is powered by a 6 to 15 volt source using the
VIN and VSS (ground) pins. The VDD pin can be used to power other circuitry provided that the overall
current consumption is within the capabilities of the BASIC Stamp’s regulator."

My take on that statement is that the Stamp when its powered by, say a logic level supply it gets delivered via the VDD pin.

However when either the connectors for the 9V battery are used and its being delivered via the VIN pin, the VDD one makes available 5v to the outside world.

However is that also at a TTL VCC level? I typically use only TTL logic, which is SN7437 type. (Quad NAND gate buffer type), for example and that's what it expects. (TI original part number.)

Would someone more familiar with the stamp's internal arrangements then I please check my facts. :eyes:

Comments

  • PJAllenPJAllen Banned Posts: 5,065
    edited 2010-09-10 20:55
    V_in is the supply voltage that feeds the on-board regulator.
    V_cc is the on-board regulator's output, 5V. TTL = 5V = TTL.
  • Buck RogersBuck Rogers Posts: 2,187
    edited 2010-09-11 14:05
    PJ Allen wrote: »
    V_in is the supply voltage that feeds the on-board regulator.
    V_cc is the on-board regulator's output, 5V. TTL = 5V = TTL.

    Hello!
    Thank you PJ. This confirms that I won't need to contrive a second supply for the logic that the Stamp will be talking to, and listening to responses from.

    I plan on demonstrating some ideas to a group of people in days to come so this will be good to know. :smilewinkgrin:
  • Mike GreenMike Green Posts: 23,101
    edited 2010-09-11 14:25
    Generally, the 5V regulator on the Stamp module is adequate if you're only running a small amount of logic from it (maximum of 50mA). If you need more than that, you'll need a larger +5V regulated supply. You can run the BS1 off the same supply or you can continue to use the regulator on the module with any input supply voltage of 6V or greater.
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