diff options
| -rw-r--r-- | fw/main.c | 9 |
1 files changed, 7 insertions, 2 deletions
@@ -29,6 +29,7 @@ #define TACH_FACTOR 15000000ul #define TMR1_POST 6u // TMR1 postscaler -- must be multiple of 2 #define EDGE_PER_PULSE 2u // rising and falling edge +#define MIN_TACH_PULSE_PER_MIN 229u // (pulse/min) >= TACH_FACTOR / (2^16) // Signals typedef enum { @@ -173,7 +174,6 @@ main(void) { INTCON = 0x00; // clear flags OPTION_REGbits.INTEDG = 0; // interrupt on falling edge of INT pin INTE = 1; // enable INT pin - TMR1IE = 1; // enable TMR1 interrupts PEIE = 1; // enable peripheral interrupts GIE = 1; // enable global interrupts @@ -325,7 +325,12 @@ handleSigCtrlFrame(const CanFrame *frame) { // Set frequency of tachometer output signal. static void driveTach(U16 pulsePerMin) { - tmr1Start = (((U32)1ul<<16u) - (U32)TACH_FACTOR / (U32)pulsePerMin) & 0xFFFF; + if (pulsePerMin < MIN_TACH_PULSE_PER_MIN) { + TMR1IE = 0; + } else { + TMR1IE = 1; + tmr1Start = (((U32)1ul<<16u) - (U32)TACH_FACTOR / (U32)pulsePerMin) & 0xFFFF; + } } // Generate the output signal being sent to one of the gauges. |