|
Title: Exemple on dspic with hitech dspic compiler Post by: Yazi on December 29, 2005, 09:26:29 09:26 //this exemples are tested on the hard with dspic30f2010 it work fine
//using timer1 #include #include #define PLL_VALUE 8.0 #define CLOCK_TICKS 4000000 #define TCY_PER_SECOND (PLL_VALUE*CLOCK_TICKS/4.0) #define PRE_SCALE 256.0 void setupTimer1(float timeInS) { unsigned long period; period=(unsigned long)(timeInS*TCY_PER_SECOND/PRE_SCALE)-1; SetPriorityIntT1(3); EnableIntT1; OpenTimer1(T1_ON & T1_GATE_OFF & T1_IDLE_STOP & T1_PS_1_256 & T1_SYNC_EXT_OFF & T1_SOURCE_INT,period); } void interrupt tc_int(void) @ T1_VCTR { T1IF=0; WriteTimer1(0); LATE++; } int main(void) { TRISE=0; setupTimer1(1.0); // argument is interval (in seconds) between interrupts while(1); } //e using timer2 #include #include #define PLL_VALUE 8.0 #define CLOCK_TICKS 4000000 //External 4Mhz cristal #define TCY_PER_SECOND (PLL_VALUE*CLOCK_TICKS/4.0) #define PRE_SCALE 256.0 void setupTimer2(float timeInS) { unsigned long period; period=(unsigned long)(timeInS*TCY_PER_SECOND/PRE_SCALE)-1; SetPriorityIntT2(1); EnableIntT2; OpenTimer2(T2_ON & T2_GATE_OFF & T2_IDLE_STOP & T2_PS_1_256 & T2_SOURCE_INT &T2_32BIT_MODE_OFF,period); } void interrupt tc_int(void) @ T2_VCTR { T2IF=0; WriteTimer2(0); LATE++; } int main(void) { TRISE=0; setupTimer2(1.0); // argument is interval (in seconds) between interrupts while(1); } //if you tray with Setuptimer2(3.0) you have only 0.902816 second as interval betwin interrupt //because periode =((3*4000000*8)/4*256)-1 =16E35 the PR2 is only 16bits he take only 6E35=28213 //calcul interval betwin interrupt= (PLL_VALUE*CLOCK_TICKS/4.0*PRE_SCALE)/28213= 902.816ms //Simulation under MPLAB give 902.942125 ms // exemple 3 timer 2and 3 as 32 bits timer mode with dspic compiler #include #include #define PLL_VALUE 8.0 #define CLOCK_TICKS 4000000 #define TCY_PER_SECOND (PLL_VALUE*CLOCK_TICKS/4.0) #define PRE_SCALE 256.0 void setupTimer23(float timeInS) { unsigned long period; period=(unsigned long)(timeInS*TCY_PER_SECOND/PRE_SCALE)-1; SetPriorityIntT2(3); EnableIntT3; OpenTimer23(T2_ON & T2_GATE_OFF & T2_IDLE_STOP & T2_PS_1_256 & T2_SOURCE_INT &T2_32BIT_MODE_ON,period); } void interrupt tc_int(void) @ T3_VCTR { T3IF=0; WriteTimer23(0); LATE++; } int main(void) { TRISE=0; setupTimer23(1); // argument is interval (in seconds) between interrupts while(1); } //with 32bit timer the interval betwin interrupts can go to 137438.95 sec (near 38 hours);) |