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Sandman
Joined: 26 Jan 2004
Posts: 15
Location: Kiruna, Sweden
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| My 16f676 is sleepy |
 Posted: Wed Mar 03, 2004 4:51 pm |
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I am trying to get my pic to wake up from sleep by using overflow interrupt on timer1.
The interrupt works. Without the sleep command it works as it should, but if sleep is introduced it will not wake up. I have even moved into the dangerous field of assembler to be sure that the right bits in the concerned registers is set (the c code for each assambler part is also included but not compiled), but the pic is still sleepy.
Please, teach me how to do this right…
There must be a simple answer to this one (it usually is  ).
| Code: |
#include <16F676.h>
#device adc=8
#use delay(clock=32000)
#fuses LP, NOWDT, BROWNOUT, PUT
int snooze=0, goon=0;
/************************/
#INT_TIMER1
timer1_isr()
{
disable_interrupts(INT_TIMER1);
snooze++;
if(snooze==2) //Set number of Snooze times
{
goon=1;
snooze=0;
output_high(PIN_C3);
delay_ms(100);
output_low(PIN_C3);
}
// enable_interrupts(INT_TIMER1);
#asm
MOVLW 0x81
MOVWF 0x8c
#endasm
return goon;
}
/************************/
main()
{
/**** setup_timer_1(T1_INTERNAL | T1_DIV_BY_8); ****/
#asm
MOVLW 0x05
MOVWF 0x10
#endasm
/**** enable_interrupts(INT_TIMER1); ****/
#asm
MOVLW 0x81
MOVWF 0x8c //PIR1 REG.
#endasm
/**** enable_interrupts(global); ****/
#asm
MOVLW 0xf0
MOVWF 0x0b //INTCON REG.
#endasm
while(TRUE)
{
set_timer1(0);
while(goon==0) //Nap period
{
// sleep();
}
}
/************************************/
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//Thanks
Last edited by Sandman on Fri Mar 05, 2004 8:08 pm; edited 1 time in total |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Mar 03, 2004 7:15 pm |
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What is the clock for Timer1 ? Is it the internal instruction
clock that is derived from the main crystal oscillator ?
If so, that clock is stopped during Sleep mode. |
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Sandman
Joined: 26 Jan 2004
Posts: 15
Location: Kiruna, Sweden
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| Can still not wake up the pic |
| Posted: Fri Mar 05, 2004 3:05 am |
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I can still not get the pic (16f676) to wake up from sleep by using interrupt from timer1.
I use this code as "setup_timer1":
| Code: |
#asm
MOVLW 0x4F //Value in T1CON
MOVWF 0x10 //T1CON REG.
#endasm
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Timer is enabled, T1CON <0>
It is suppose to set timer1 to run on an external oscillator (using a 32768 Hz external crystal),T1CON<1>.
The counter is in asynchronous mode, T1CON<2>,
T10SCEN, T1CON<3> is set.
1 Prescale, T1CKS1:T1CKS0, T1CON<5:4>
The TMR1GE bit, T1CON<6> does not do any change as far as I have noticed.
What is wrong?!?! |
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SteveS
Joined: 27 Oct 2003
Posts: 126
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| Posted: Fri Mar 05, 2004 8:13 am |
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I seem to remember that you need some instructions after a sleep command before the end of the loop if the wakeup is done by interrupt. Whether this is compiler or chip related or I'm just wrong I don't know but try this:
while(TRUE)
{
set_timer1(0);
while(goon==0) //Nap period
{
sleep();
delay_cycles(2); // <--- may fix the problem
}
}
I think the same thing happened to me and this fixed it.
- SteveS |
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Sandman
Joined: 26 Jan 2004
Posts: 15
Location: Kiruna, Sweden
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| Posted: Fri Mar 05, 2004 12:12 pm |
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| Thanks for the advice, but it is hard to try since I cannot get timer1 to work at all if I set the T1CON<1>, ("TMR1CS") bit to use an external crystal oscillator. And I cannot use the internal during sleep. I believe this is the main problem, but I’ll keep your advice in mind when I get the timer woking. |
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