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David21 Guest
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Weird problem with pic |
Posted: Wed Jun 07, 2006 8:18 pm |
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My pic seems to stop working whenever I move my hand next to it (not touching the pic). I programmed an LED to blinks and it stopped blinking whenever my hand is close to the pic. It seems like i have this problem when i'm using pic+max232.
Some kind of capacitance problem?? |
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PCM programmer
Joined: 06 Sep 2003 Posts: 21708
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David21 Guest
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Posted: Wed Jun 07, 2006 8:53 pm |
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thank you. Ur so helpful. I thought I was the only one with the problem
now I can get close and personal with my pic |
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David21 Guest
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Posted: Wed Jun 07, 2006 8:54 pm |
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Why does moving my hand close to the pic cause it to reset? |
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PCM programmer
Joined: 06 Sep 2003 Posts: 21708
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Posted: Wed Jun 07, 2006 8:59 pm |
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1. Add the NOLVP fuse (assuming your PIC supports that fuse).
2. Make sure you have a pullup resistor on the MCLR pin.
Use a 10K resistor. (If you use CCS ICD, then use 47K).
3. Check all power and ground connections to the PIC. |
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Guest
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Posted: Thu Jun 08, 2006 3:37 am |
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why does adding NOLVP fix the problem? |
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Ttelmah Guest
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Posted: Thu Jun 08, 2006 4:23 am |
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When 'LVP' is selected, the chip is in a mode, where _any_ signal activity seen on the PGM pin, can put it into programming mode.
If you are using LVP, and have this fuse enabled, then ensure that you have a resistor pulling the PGM pin to 0v, or erratic behaviour may result.
The chips _default_ to this mode (this is because otherwise boards that require this feature, cannot switch to this mode, once the chip is soldered in place).
You should always disable this mode (NOLVP), _unless_ you specifically want the feature, and have wired your board to support it.
Best Wishes |
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Guest
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Posted: Fri Jun 09, 2006 3:01 am |
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thanks. I've learned something new |
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