Metal detector with PIC 12F683 and C program

PICODETECTOR CIRCUIT SCHEMATIC

PICODETECTOR SOURCE CODE

/*  *******************************************************************************  * 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++ ;                }         }

DOWNLOAD PICODETECTOR PROJECT

Download picoDetector_project.ZIP file for mikroC 

Includes :

• mikroC PRO project files for PIC12F683, should work also with most of PIC
• picoDetector C source code
• picoDetector .HEX files
• picoDetector circuit schematic