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allredsd
Joined: 02 Jun 2011
Posts: 4
Location: Austin, Texas
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| 18F45K22 Sleep and WDT wakeup |
 Posted: Tue Mar 13, 2012 10:54 am |
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I'm trying to put my 18F45K22 to sleep and have it wake up by WDT to save current when it's idle. I can't get it to work, so I've written a simple test program as provided below. I have no external crystal and am using the internal HF oscillator.
The fuses are set with this code:
| Code: |
//#FUSES WDT128 //Watch Dog Timer uses 1:128 Postscale (4ms Resolution) = 0.512 Seconds
//#FUSES WDT256 // Watch Dog Timer uses 1:256 Postscale (4ms Resolution) = 1 Seconds
//#FUSES WDT512 // Watch Dog Timer uses 1:512 Postscale (4ms Resolution) = 2 Seconds
#FUSES WDT32768 // Watch Dog Timer uses 1:1024 Postscale (4ms Resolution) = 4 Seconds
//#FUSES NOWDT //No Watch Dog Timer
//#FUSES WDT
#FUSES WDT_SW //No Watch Dog Timer, enabled in Software
#FUSES INTRC_IO //Internal RC Osc, no CLKOUT
#FUSES NOFCMEN //Fail-safe clock monitor disabled
#FUSES NOIESO //Internal External Switch Over mode disabled
#FUSES NOBROWNOUT //No brownout reset
#FUSES PUT //Enable the Power-UP Timer
#FUSES NOSTVREN //Stack full/underflow will not cause reset
#FUSES NOLVP //No low voltage prgming, B3(PIC16) or B5(PIC18) used for I/O
#FUSES NOXINST //Extended set extension and Indexed Addressing mode disabled (Legacy mode) |
and the test loop is:
| Code: | setup_adc_ports(sAN5|sAN6, VSS_VDD);
setup_adc(ADC_CLOCK_DIV_2|ADC_TAD_MUL_0);
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_16); //16=263ms //526 ms overflow
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DIV_BY_4,255/*124*/,1); //12.5 us (4kHz) overflow, 12.5 us interrupt
setup_timer_3(T3_DISABLED|T3_DIV_BY_1);
setup_timer_4(T4_DISABLED,0,1);
setup_timer_5(T5_DISABLED);
setup_timer_6(T6_DISABLED,0,1);
setup_wdt(WDT_OFF); //turn off the wdt
setup_ccp2(CCP_PWM);
set_pwm2_duty(0); //setup but disable PWM
setup_comparator(NC_NC_NC_NC);// This device COMP currently not supported by the PICWizard
enable_interrupts(INT_RTCC);
//enable_interrupts(INT_EXT);
//enable_interrupts(INT_RB);
//enable_interrupts(INT_AD);
enable_interrupts(GLOBAL);
#ifdef CLOCK_16M
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_8); //16=263ms //526 ms overflow
setup_oscillator(OSC_16MHZ|OSC_NORMAL|OSC_31250|OSC_PLL_OFF|OSC_IDLE_MODE);
#endif
#ifdef CLOCK_8M
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_16); //16=263ms //526 ms overflow
setup_oscillator(OSC_8MHZ|OSC_NORMAL|OSC_31250|OSC_PLL_OFF|OSC_IDLE_MODE);
#endif
#ifdef CLOCK_4M
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_16); //16=263ms //526 ms overflow
setup_oscillator(OSC_4MHZ|OSC_NORMAL|OSC_31250|OSC_PLL_OFF|OSC_IDLE_MODE);
#endif
int minutes = 0;
int seconds = 0;
int1 pir_active = 1;
int1 run_timer=0;
int1 delay_pir=1;
int1 timer_on = 1;
int1 display_on = 0;
int current_state = STATE_INITIALIZE;
int next_state = STATE_STOPPED;
minutes = read_eeprom(EE_MINUTES);
seconds = read_eeprom(EE_SECONDS);
pir_active = read_eeprom(EE_PIR_ACTIVE);
timer_on = read_eeprom(EE_TIMER_ON);
display_on = read_eeprom(EE_DISPLAY_ON);
WHY_RESET = restart_cause();
//** Turn off Unused Periperals - see datasheet
MCU_PMD0 = 0xFD; //all peripherals off except Timer2
MCU_PMD1 = 0xDD; //all peripherals off except CCP2
MCU_PMD2 = 0x0E; //all peripherals off except ADC
while(1)
{
light_led(BLUE);
delay_ms(750);
dark_led(BLUE);
setup_wdt(WDT_ON);
sleep();
delay_cycles(1);
} |
The LED Lights and turns off, then turns back on again (blinking). I don't ever hit the restart_cause() statement, so it appears that the processor isn't going to sleep and being reset by the WDT (I'm running in debugger). Any help would be greatly appreciated!!
Thanks.
Scott |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Mar 13, 2012 11:17 am |
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| Quote: |
I'm trying to put my 18F45K22 to sleep and have it wake up by WDT.
I'm running in debugger.
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Look at the Help file for ICD2 in MPLAB. Type in 'sleep' and search for it.
Result:
| Quote: |
PIC18F Extended, PIC18FXXK Limitations
- The SLEEP instruction cannot be used when debugging.
- The Watchdog Timer (WDT) cannot be used when debugging. |
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allredsd
Joined: 02 Jun 2011
Posts: 4
Location: Austin, Texas
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| Posted: Tue Mar 13, 2012 11:22 am |
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I've tried burning it into rom and get the same results  |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Mar 13, 2012 11:37 am |
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1. Make sure your IDE is set to compile and program in "Release" mode.
(not "debug" mode).
2. Simplify your program. Cut out about 90% of your code and test it
again. For example, you have tons of commented out lines, and you have
many lines to setup the Timers, and tons of #ifdefs for different clock
rates. Cut it all out and make a really simple test program. Simplicity
will allow you to see the problem more easily. |
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allredsd
Joined: 02 Jun 2011
Posts: 4
Location: Austin, Texas
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| Posted: Tue Mar 13, 2012 2:26 pm |
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I've found the reason I'm not sleeping or WDT-ing...I had
in my header file. Once I've got that commented out I can see that I'm going to sleep, and waking up on WDT.
For a follow on, I don't seem to be seeing a significant current savings when I go to sleep. Do I have to manually set up the sleep mode before I call sleep() ? |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Mar 13, 2012 3:36 pm |
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| Quote: |
Do I have to manually set up the sleep mode before I call sleep() ? |
Yes, you do. You have to turn off all modules that consume power,
such as the A/D converter, the comparators, Vref generator, etc.
You also have to set all unused i/o pins so they are not floating.
Set unused pins to a low level. If you have an external pull-up or
pull-down resistor on a pin, then set that pin to be an input (ie., floating).
And the truth is, all your unused i/o pins that are not externally
terminated should be set to "output low" during normal operation as well,
so you won't use unnecessary amounts of current due to floating inputs. |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19439
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| Posted: Wed Mar 14, 2012 2:38 am |
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Also, 'think' about what else may be drawing power.
There was another thread involving sleep only a few days ago, and the poster was using a7805 regulator. Problem is that these will typically draw about 5mA, with no load. Possibly 1000* what the PIC may be drawing....
Best Wishes |
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