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Boe-Bot possible power problem — Parallax Forums

Boe-Bot possible power problem

JMillerJMiller Posts: 3
edited 2006-07-14 06:07 in Robotics
Howdy All,

I was hoping that one of y'all could help me with a technical question on my Boe-Bot.

I was following the book that came with it and got stuck on page 18.

My Boe-Bot doesn't seem to be getting power as the little green Led light won't turn on no matter what I do. (I did turn the switch to position 1 by the way.)

I used a mult-o-meter to check the batteries and the battery pack which both seem to be in order. The rest of the board has a good deal of resistance though.

I tried to identify it just hoping that the Led was broke but it won't read the board which I assume is because it doesn't have any power. Loopback and Echo both came up as yes but device type remained blank.

Go easy on me if you would as I am not much of an electrician or computer person (currently in the medical field).

Thanks,

Jeff

Comments

  • A.C. fishingA.C. fishing Posts: 262
    edited 2006-07-09 15:57
    Maybe one of your battery pack wires came loose.

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    Somebody said...
    -Never Underestimate the power of human stupidity.
    ·
  • Matt WhiteMatt White Posts: 60
    edited 2006-07-09 16:00
    Jeff,

    First, I would take the stamp out of the board while working on it. Second, I would use your voltmeter to test the voltage on the VIN and VDD lines. The voltage on VIN should come direct from the battery. If your battery is providing 8.5v or whatever, you should read that exact same voltage on the VIN lines. Next try measuring the voltage on your VDD lines. This voltage should is regulated to 5v and that's what you should read on your voltmeter. I'd try changing your batteries or using a 9v wall adapter (1Amp or less).

    If you have 5v on your VDD lines then turn the board off, put the stamp in, and try and run a test program on it.
    Something simply like:

    DEBUG "Hello, World!", CR
    END

    If anything on the board is damaged its likely to be the voltage regulator, which you could either get ahold of Parallax to have the board replaced, or order a new regulator and replace it yourself (unsolder the old one and solder the new one into place).

    Matt
  • Bruce BatesBruce Bates Posts: 3,045
    edited 2006-07-09 17:16
    Jeff -

    If there is an electrical problem caused by a blown component on the actual Stamp itself (in the final analysis), Parallax offers a very reasonable repair service. I mention this just in case you weren't aware of it, and am not suggesting that's the cause of your present problem.

    Regards,

    Bruce Bates

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  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-07-09 17:29
    Just as a note, when the battery pack is connected, regardless of the power switch position, you can read the voltage coming into the board at the Battery Clip Terminals.· Make sure the battery pack voltage is making it that far.

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • JMillerJMiller Posts: 3
    edited 2006-07-10 01:45
    Chris,

    Thanks I didn't know that.

    Bruce,

    I will keep that in mind though I just purchased the kit so I am hoping that the error is with the user and not the bot.

    A.C.,

    Battery pack wires don't seem to be the problem but thank you for the suggestion.

    Matt,

    Thanks for the recommendation with the stamp. Never really thought about that. As for the VIN and VDD I am a bit confused by the terminology·but I can explain what I have done in laymans terms and maybe even learn something [noparse]:)[/noparse]

    I tested the batteries (went through a·12 pack of·batteries to see if any would work).·I·measured the voltage on each portion of the battery pack, the battery pack wires, and the·female socket that the·battery pack hooks into and it all read the correct voltage, 6 volts as it is 4 1.5 volt batteries.

    I don't know what to do further from here.

    Thanks for all the help so far,

    Jeff

    ·
  • Matt WhiteMatt White Posts: 60
    edited 2006-07-11 05:06
    Jeff,

    VDD is regulated 5v (I have no idea what VDD stands for, I've also seen it called VCC).· VIN is always direct power from the battery and VSS is ground.·· I'm sure there is a reason for the naming convention but I'm not familure with it.

    Anyway... here are a few pictures.

    P7100058.JPEG: My BOE connected to the 6v battery pack (4 x 1.5v AA batteries).· My voltage with recently recharged batteries measures about·5.07v.

    P7100067.JPEG: I disconnected the BOE's battery pack and connected a 9v rechargable battery (to show the difference between VIN and VDD.· Measuring the voltage on the VIN lines I read 8.35v.

    P7100068.JPEG: I moved my voltmeter from VIN to VDD where I'm measuring the regulated voltage at 5.01v.

    Hope that helps clarify things!· Check to make sure you have your batteries connected in the right order.· Testing with a 9v battery can rule out any issues you might have with battery pack vs. the BOE board.
    P7100058.JPG
    1600 x 1200 - 446K
    P7100067.JPG
    1600 x 1200 - 443K
    P7100068.JPG
    1600 x 1200 - 330K
  • JMillerJMiller Posts: 3
    edited 2006-07-13 13:50
    Matt,

    Figured it out. There is something wrong with my battery pack and the way it connects to the board. The pack itself seems to be fine to me (wiring wise and the batteries are good and placed correctly also). Maybe it is some form of connection problem.

    none the less a simple 9V did wonders. It is now powering up and being identified by the program. So everything is great. Have to man the ambulance 24hrs tomorrow but after that Saturday is going to be full of programming. makes me wish my laptop was still kicking.

    Just want to say thank you to everyone who posted.

    Take care,

    Jeff
  • Matt WhiteMatt White Posts: 60
    edited 2006-07-13 14:53
    Jeff,

    Very good - I'm glade your up and running again! You can order a replacement battery pack made for the BOE here:
    http://www.parallax.com/detail.asp?product_id=700-00038

    Best of luck on your programming!
    Matt
  • RongRong Posts: 25
    edited 2006-07-14 06:07
    About half of all of the electronics devices I have repaired have been bad connections, bad solder joints, or other simple breaks in the continuity of a circuit. I always check the simplest thing first. If a device is completely dead, it is usually easier to repair than the devices with more complicated problems..A VOM is the number one repair instrument, followed by a hot soldering iron.

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    Ron Giuntini

    San Francisco
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