DB101 delay inturrupt

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waspinator
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#1
Posted by waspinator: Wed. Jul 22, 2009 - 09:29 PM
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Hi,

I'm playing around with a DB101 and I'd like to exit a loop once the joystick enter is pressed. The problem is that when I use _delay_ms() (in delay_x_gcc.h) it seems it only checks if the joystick enter is pressed BETWEEN delays. This makes it difficult to exit the loop, and requires luck.

How can I interrupt _delay_ms(1000) and exit the loop EVERY time the joystick enter is pressed?

I wouldn't even mind waiting 1000 ms and letting _delay_ms(1000) finish before it exits if that makes it easier.

while (!JOYSTICK_IsEnterPressed())
{
  _delay_ms(1000);
}

Thanks,

Waspinator

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Tools, Compilers and General Programming
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Bronze MarkJohanEkdahl
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Posted by JohanEkdahl: Wed. Jul 22, 2009 - 11:46 PM
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Here's one solution: Do several much shorter delays, so short that you are sure to catch a closed switch. Maybe a thousand delays of 1 ms?

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Gold Markclawson
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Posted by clawson: Thu. Jul 23, 2009 - 08:38 AM
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Quote:

How can I interrupt

The answer to your question is in your question ;-)

If you did your delays with a timer interrupt rather than a software loop you'd be free to get on with other stuff while waiting for the interrupt handler to signal the completion of the measured period of time.

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waspinator
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Posted by waspinator: Thu. Jul 23, 2009 - 03:43 PM
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I was actually already thinking of using interrupts, I just wasn't sure how I would do that. I would like to be able to keep using delay_x_gcc.h to wait if that's possible though.

I'm brand new to AVR, so can you give me a code snippet on how I would do this, or maybe point to somewhere where I could find out more?

Thanks,

Waspinator

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