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IR Boe bot

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  • bee896bee896 Posts: 25
    edited 2010-10-13 08:25
    Oo.. Now I know the differences. Well I'm using 4 Energizer 2450 mAh batteries, so it should be able to last longer than normal alkaline batteries
  • Mike GreenMike Green Posts: 23,101
    edited 2010-10-13 08:52
    Since you're using NiMH rechargables, you really do want the 5th cell. 4 NiMH cells put out about 1.2V each for a total of 4.8V. That's ok for servo motors, but that's already below the point where the voltage regulators for the logic can work. They need a minimum of about 5.3V to regulate properly and have a further voltage drop of about 0.2V to 0.3V leaving only 4.5V for the logic circuitry to work. The Stamp itself won't work below about 4.3V so it'll quit before the batteries completely exhaust themselves.

    You can buy a cheap single AA cell holder that you can mount with glue or double sided foam tape on the back of the BoeBot above the ball then wire in series with one of the leads from the 4 x AA battery holder. It's more difficult to charge 5 AA cells than 4 because most chargers are made for 4 cells. I happen to have a charger that works with any number of cells up to 8 and you can make your own constant current charger using an LM317 voltage regulator as a current limiter.
  • bee896bee896 Posts: 25
    edited 2010-10-13 12:37
    Oh no wonder the batteries die off so incredibly fast with all the servos running.
    I think I prefer the Boe-Boost than a DIY battery holder.
    No offense here since I'm not good with electronic stuffs. I'll try discussing with my lecturer first to see if I can get a BoeBoost or I'll end up doing the DIY battery holder. :)
  • bee896bee896 Posts: 25
    edited 2010-10-14 04:22
    Mike Green wrote: »
    Since you're using NiMH rechargables, you really do want the 5th cell. 4 NiMH cells put out about 1.2V each for a total of 4.8V. That's ok for servo motors, but that's already below the point where the voltage regulators for the logic can work. They need a minimum of about 5.3V to regulate properly and have a further voltage drop of about 0.2V to 0.3V leaving only 4.5V for the logic circuitry to work. The Stamp itself won't work below about 4.3V so it'll quit before the batteries completely exhaust themselves.

    You can buy a cheap single AA cell holder that you can mount with glue or double sided foam tape on the back of the BoeBot above the ball then wire in series with one of the leads from the 4 x AA battery holder. It's more difficult to charge 5 AA cells than 4 because most chargers are made for 4 cells. I happen to have a charger that works with any number of cells up to 8 and you can make your own constant current charger using an LM317 voltage regulator as a current limiter.

    Hi Mike, I just bought a single AA cell holder that you mentioned and I would like to install them on the BoeBot. However, I'm afraid I would need more detailed information on how to do it since I've never done it before.
    About the BoeBoost, it would take a long time buying through online since my lecturer never bought them together with the BoeBot, so I think the battery holder is currently the best alternative
  • william chanwilliam chan Posts: 1,326
    edited 2010-10-14 04:53
    Actually your Uni did buy 20 units of BoeBoost recently.
    Ask your lecturer to check with Adam, the supplier.
  • bee896bee896 Posts: 25
    edited 2010-10-14 05:05
    About my Uni, do you mean UTeM?
    Yeah, and I just asked him and he said that he already got it last week and forgot to give us. So now I'll just have to bear with all the lack of voltage. Awwwwww
  • william chanwilliam chan Posts: 1,326
    edited 2010-10-14 05:44
    Until you get the BoeBoost, use alkaline batteries first.
    Giant, Tesco or Carefour alkaline batteries are quite cheap.
  • william chanwilliam chan Posts: 1,326
    edited 2010-10-14 15:57
    Here is the latest mouse chasing the Propeller bot code.
    The Boe Bot mimics the fine movements of the PS/2 mouse.
    It is much improved from your lecturer's code.
  • bee896bee896 Posts: 25
    edited 2010-10-15 07:42
    thanks again for all the samples and working codes.
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