HCS12DT256 Resets

Discussion in 'Embedded Systems and Microcontrollers' started by zoozd, Apr 3, 2013.

  1. zoozd

    Thread Starter New Member

    Apr 3, 2013
    7
    0
    Hey,

    I'm designing a parallel parking car using the HCS12DT256. Everything has been great until it started restarting right in the middle of parking. It might reset after a second, or after 10 seconds, rarely it never does it.

    The thing is that it used to complete the parking without resetting, then it started doing that although all the things that I have changed (hardware and software wise), I have removed it again to determine the source of error.

    I have checked for shorts.

    My power supply is a +7 volts dc power supply. Also used 9 volts batteries, both gave the same result.

    I know that it resets because the LEDs blink and the car stops and waits for my Start input. However the VDD led never blinks.

    There is no error in the software, I am 100% sure.

    I have put capacitors around the power supplies.

    Any ideas? Any suggestions how to prevent it from resetting?
     
  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,392
    1,605
    It may be a power issue. You could check this simply by adding power cables to separately supply the processor and the motors: this may help isolate them. If the problem goes away then you have a direction to begin.

    I wonder how you have assured yourself "(t)here is no error in the software" to 100% confidence.
     
    zoozd likes this.
  3. zoozd

    Thread Starter New Member

    Apr 3, 2013
    7
    0
    If it was a power (voltage) issue then the Vdd LED would blink. I already have it hooked up to a dc power supply which I can vary, and I have used it over a range of 6-9volts and the same thing happens.

    I'm sure because sometimes it can do the whole parking thing, and sometimes it can do half of it although it is loading the same code with the same sizes. When it resets it is usually inside any of the functions that I have (it is extremely random).
     
  4. zoozd

    Thread Starter New Member

    Apr 3, 2013
    7
    0
    Thank you very much, this worked, you are a genius.
     
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