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BOE problem NOOB Help — Parallax Forums

BOE problem NOOB Help

joecamaro68joecamaro68 Posts: 8
edited 2010-12-04 12:06 in Robotics
Hello,
I inherited a new BOE BOT kit with a serial BOE. After I have it hooked up with a 9VDC wall wart, I measure VCC on the chip and see a nice 5VDC like I should. When I measure VCC on the proto headers I only see 2.2 VDC...Is this normal?

Comments

  • W9GFOW9GFO Posts: 4,010
    edited 2010-12-04 10:02
    Do you mean the pins labeled 0 through 15?

    Rich H
  • joecamaro68joecamaro68 Posts: 8
    edited 2010-12-04 10:58
    Hello Rich,
    I have a BS2 chip in a BOE, powered by a 9VDC wall wart. When I measure pin 21 on the BS2 (labeled VCC on the board) I see 5VDC as I should. When I measure the pin labeled Vdd on the header next to the proto typing area (or on the other header in the middle of the board) I get 2.2VDC. I do not see anything in the BOE schematic that would indicate a voltage drop.

    By the way, when a run a test program to rotate a servo it runs,
  • hover1hover1 Posts: 1,929
    edited 2010-12-04 11:21
    joecamaro68 wrote: »
    Hello Rich,
    I have a BS2 chip in a BOE, powered by a 9VDC wall wart. When I measure pin 21 on the BS2 (labeled VCC on the board) I see 5VDC as I should. When I measure the pin labeled Vdd on the header next to the proto typing area (or on the other header in the middle of the board) I get 2.2VDC. I do not see anything in the BOE schematic that would indicate a voltage drop.

    By the way, when a run a test program to rotate a servo it runs,

    Vdd is generated by the 5 volt regulator (LM340 - 5), Vcc is generated on board the BS2 from the Vin voltage, ( by it's own regulator). You may have a bad regulator. The reason you servo test ran is probably the jumper between the servo headers was set to Vin and not Vdd.

    Jim
  • W9GFOW9GFO Posts: 4,010
    edited 2010-12-04 11:23
    It sounds like the regulator on the BOE is either bad or something is trying to pull too much current through it.

    Rich H
  • joecamaro68joecamaro68 Posts: 8
    edited 2010-12-04 12:06
    This is all with no circuit connected. I'll have to look at the regulater.
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