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Revision as of 17:24, 7 February 2012
/*
******************************************************************************* * picoDetector : an ultra simple and cheap metal detector ******************************************************************************* * * Author : Bruno Gavand, april 2009 * see more details on http://www.micro-examples.com/ * * source code for mikroC PRO compiler V1.65 * feel free to use this code at your own risks * * target : PIC12, oscillator in HS mode, watchdog enabled * * PIC PIN Assignemnt : * * GP0 : detect LED indicator * GP1 : calibrate LED indicator * GP2 : NC * GP3 : NC * GP4, GP5 : inductor * ******************************************************************************* */
- define MAXTRY 15 // number of watchdog restart to calibrate loop counter
unsigned char ctr ; // number of loops between two watchdog resets unsigned char previous ; // previous value of ctr unsigned char calibr ; // calibration value when oscillator runs free unsigned char restarts ; // number of watchdog restarts unsigned char en ; // enable flag, allows detection
/*
* main loop */
void main()
{
unsigned char i ;
/*
* configure GPIO as digital port
*/
CMCON0 = 7 ;
ANSEL = 0 ;
TRISIO = 0 ;
GPIO = 0 ;
/*
* power up ?
*/
if(STATUS.NOT_TO)
{
/*
* yes, init variables
*/
restarts = 0 ;
calibr = 1 ;
}
/*
* watchdog reset counter
*/
if(restarts < 255) restarts++ ;
/*
* if counter differs too much from calibration value
*/
if((previous ^ ctr) > calibr)
{
/*
* turn detect LED on
*/
GPIO.F0 = en ;
/*
* if not on power up
*/
if(STATUS.NOT_TO == 0)
{
/*
* while in calibration mode
*/
if(restarts < MAXTRY)
{
/*
* shift calibration value
* and wait a little bit
*/
calibr <<= 1 ;
Delay_ms(5) ;
}
}
else
{
/*
* turn detect LED off
*/
GPIO.F0 = 0 ;
}
}
/*
* save last counter
*/
previous = ctr ;
/*
* is calibration over ?
*/
if(restarts > MAXTRY)
{
/*
* yes, turn calibrate LED off
* and set enable flag
*/
GPIO.F1 = 0 ;
en = 1 ;
}
else
{
/*
* no, turn calibrate LED on
* and clear enable flag
*/
GPIO.F1 = 1 ;
en = 0 ;
}
/*
* set watchdog prescaler
*/
OPTION_REG = 0b11111001 ;
/*
* start counter, to be interrupted by watchdog
*/
ctr = 0 ;
for(;;)
{
ctr++ ;
}
}