Serial Timeout Strange Issues


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  1. #1
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    Default Re: Serial Timeout Strange Issues

    Any noise on the line will cause the time out to be reset. Is this an RF project?
    Dave
    Always wear safety glasses while programming.

  2. #2
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    Default Re: Serial Timeout Strange Issues

    No both chips are on the same board about 2 inches apart with a wire going through a 1k resistor to the other chip. How do I filter out the noise, if any, without filtering out the signal?

  3. #3
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    Default Re: Serial Timeout Strange Issues

    Noise should not be the problem then.

    Post your code and we will see if there is anything there.
    Dave
    Always wear safety glasses while programming.

  4. #4
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    Default Re: Serial Timeout Strange Issues

    I am guessing you are powering the pics from the same supply as the servo. A little electric motor like that can generate some serious voltage (back EMF) and distribute it back into the power supply. I would power them seperately and tie the grounds all at a single place.
    If you do not believe in MAGIC, Consider how currency has value simply by printing it, and is then traded for real assets.
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  5. #5
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    Default Re: Serial Timeout Strange Issues

    No the servos and chips have seperate power supplies with connected ground as I ran into that problem before
    Here is my code

    Receiver

    Define osc 4
    trisa = %000000
    trisb = $00
    low portb
    t1pulse var byte[6]
    t1pulse[0] = 90
    t1pulse[1] = 90
    t1pulse[2] = 90
    t1pulse[3] = 90
    t1pulse[4] = 90
    t1pulse[5] = 90
    porta.1 = 1
    porta.2 = 0
    trisa.3 = 1

    Main:
    porta.2 = 0 'turns on a transistor that brings pin on sender high
    'to stop it from sending the serial

    pulsout portb.3,t1pulse[0] + 60 'pulsout for servos
    pulsout portb.2,t1pulse[1] + 60
    pulsout portb.1,t1pulse[2] + 60
    pulsout portb.4,240 - t1pulse[3]
    pulsout portb.5,240 - t1pulse[4]
    pulsout portb.6,240 - t1pulse[5]

    porta.2 = 1 'turns transistor on to bring sender pin low to
    'tell sender to send

    Serin2 porta.3,84,15,Comfail,[wait ("@"), str t1pulse\6] 'if timeout length
    ' is longer than the time between the sends
    'on the sender, this line hangs up and chip
    'acts weird like turning porta.2 on but not
    ' sending the pulses or turn on servo pins
    ' and never turn off

    porta.2 = 0 'tell sender to stop sending

    goto main 'loop to main

    Comfail: 'if sendin timesout, go here.
    Porta.2 = 0 'tell sender to stop sending
    goto main 'goto main

    The sender does some calculations and sends an array of size 6 through a pin and doesn't do anything else with that pin, just serout2 and then continues on with the program. If the time it takes the sender to send is longer than the timeout the receiver doesn't work correctly.

  6. #6
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    Default Re: Serial Timeout Strange Issues

    Here is a shot in the dark.
    You have not posted any config fuses in your code so I am free to assume you are allowing your code to use the Default configs which are located in the 16F84.inc file found in your PBP root directory.
    This is the default MPASM config:
    __config _XT_OSC & _WDT_ON & _CP_OFF
    and here is the PM default config:
    device pic16F84, xt_osc, wdt_on, protect_off
    it defaults to WDT_ON, I think your code is hanging waiting and the WDT resets and the follies begin. You should early in your PIC programming career learn how to set them in your code so there are no surprises.
    It is explained in this thread:
    http://www.picbasic.co.uk/forum/showthread.php?t=543
    Last edited by Archangel; - 8th June 2011 at 10:13. Reason: add
    If you do not believe in MAGIC, Consider how currency has value simply by printing it, and is then traded for real assets.
    .
    Gold is the money of kings, silver is the money of gentlemen, barter is the money of peasants - but debt is the money of slaves
    .
    There simply is no "Happy Spam" If you do it you will disappear from this forum.

  7. #7
    Join Date
    Jun 2011
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    Default Re: Serial Timeout Strange Issues

    I tried turning off the watchdog timer and it didn't change. Thanks for the sggestion.

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