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edi
Joined: 22 Dec 2003
Posts: 82
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| 10F200 power up problem |
 Posted: Mon Nov 26, 2012 3:32 am |
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I have 10F200 working with one CR2032 battery and blink 2 LEDs randomly, start to work after pushing a tact switch.
The problem - sometimes after insertion of the battery to LEDs start to blink without touching the tact switch.
Any idea?
MPLAB 8.80
PCWHD 4.12
| Code: |
#include <10F200.h>
#fuses WDT,NOMCLR,NOPROTECT
#use delay(clock=4000000)
#use fast_io(B)
#byte portb=0x06
#byte OSCCAL=0x05
#bit SPARE = portb.0
#bit LED1 = portb.1
#bit LED2 = portb.2
#bit TACT = portb.3
short ON_OFF;
unsigned int MY_RANDOM;
#define set_options(value) {#ASM \
MOVLW value \
OPTION \
#ENDASM}
void check_TACT()
{
int8 i;
delay_ms(30); //debounce
if (!TACT)
{
LED1 = 0;
LED2 = 0;
delay_ms(1000); //long press to turn off
if (!TACT)
{
restart_wdt();
for (i=0; i<5; i++)
{
LED1 = 0;
LED2 = 1;
delay_ms (200);
LED1 = 1;
LED2 = 0;
delay_ms (200);
}
LED2 = 1;
ON_OFF=0;
sleep();
}
}
LED1 = 1;
LED2 = 1;
}
void init()
{
OSCCAL = OSCCAL & 0xFE; //this is a must to enable GP2 as IO and not FOSC
LED1 = 1;
LED2 = 1;
TACT = 1;
SPARE = 1;
set_tris_b(0b1000);
setup_wdt(WDT_2304MS);
restart_wdt();
}
void main()
{
unsigned int8 loop, i, ZROR, y;
set_options(0b01010111); //enable wake on change and disable pullups
y = restart_cause(); // This must be first execution in the main!!!
init();
if (y == NORMAL_POWER_UP) //Reset cause by NORMAL P.U
sleep();
if ((y & 0x90) == 0x90) //PIN_CHANGE_FROM_SLEEP
{
MY_RANDOM=0b11001011; //This is the sequence of blinking
ON_OFF = 1;
}
else if (!ON_OFF)
sleep();
while(1)
{
restart_wdt();
ZROR = (MY_RANDOM & 0b00000111);
for (loop=0; loop<ZROR; loop++)
{
LED1 = 0; //LED ON
LED2 = 0; //LED ON
delay_ms(10);
LED1 = 1;
LED2 = 1;
delay_ms(100);
}
rotate_right (&MY_RANDOM,1);
if (!TACT)
check_tact();
sleep();
}
}
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Mike Walne
Joined: 19 Feb 2004
Posts: 1785
Location: Boston Spa UK
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| Posted: Mon Nov 26, 2012 4:15 am |
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Have you allowed for coin cell connection bouncing as you insert?
Mike |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19515
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| Posted: Mon Nov 26, 2012 4:34 am |
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Several little things:
First as Mike says, connection bounce.
Then you are not initialising ON_OFF. It could contain anything (think how this affects your code). Initialise it in code called for NORMAL_POWER_UP.
Then - same problem, you are not reading the input before entering sleep. Data sheet:
"Caution: Right before entering Sleep,
read the input pins. When in Sleep, wakeup
occurs when the values at the pins
change from the state they were in at the
last reading. If a wake-up on change
occurs and the pins are not read before reentering
Sleep, a wake-up will occur
immediately even if no pins change while
in Sleep mode."
Problem is the pin change latch can get set during power on. Then you will get an immediate wake up (won't sleep), and with ON_OFF containing random values, it can then fall through your routines into the flash code.
Your set_options code, breaches the comment: "// This must be first execution in the main!!! ". Setting options can affect the bits seen, reading restart_cause should be done first.
Best Wishes |
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edi
Joined: 22 Dec 2003
Posts: 82
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| Posted: Mon Nov 26, 2012 5:47 am |
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Many thanks,
Will try it and update.
Regards. |
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edi
Joined: 22 Dec 2003
Posts: 82
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| Posted: Mon Nov 26, 2012 6:17 am |
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Additional 2 question please:
1. What can be done regarding the coin battery connection bounce?
2. The board cost is very critical, is there a need for coupling capacitor while using only direct CR20302 battery? |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19515
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| Posted: Mon Nov 26, 2012 8:30 am |
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Yes. Something like a 0.1uF ceramic though, not an electrolytic. Cost lower, and has better performance at high frequencies (which is where it matters). Whether you need more capacitance than this, will depend on what else is on your board. Anything that 'switches', implies more need for capacitance.
Best Wishes |
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temtronic
Joined: 01 Jul 2010
Posts: 9228
Location: Greensville,Ontario
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| Posted: Mon Nov 26, 2012 8:38 am |
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also..
if applicable add PUT to the fuses. PowerUpTimer option allows the PIC to 'stabilze' on powerup making for a 'clean' start.
add a delay_ms(500); to your main code before you do any checking. Again to help the PIC get 'organized' and 'settled'.
As previously stated, preset all variables with default values,clear any interrupts,etc.
hth
jay |
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edi
Joined: 22 Dec 2003
Posts: 82
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| Posted: Tue Nov 27, 2012 12:11 am |
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Updated my code with all your recommendations.
Now its working perfect.
THANKS. |
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