Simple revolution counter with custom IRQ handler and IO macros
Dependencies: TextLCD mbed SimpleIOMacros
Diff: main.cpp
- Revision:
- 0:2352ac8d6438
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Wed Jun 01 09:36:16 2011 +0000 @@ -0,0 +1,76 @@ +/* +Simple revolution counter, works stable for 1 - 50000 rpm's +Uses 1 pulse/revolution at pin 10 +*/ +#include "mbed.h" +#include "TextLCD.h" +#include "IOMacros.h" + +Ticker timer; +Timer t; +DigitalOut led(LED1); +volatile float count,oldcount, revf; +int rev; + +TextLCD lcd(p15, p16, p17, p18, p19, p20, TextLCD::LCD16x1); + + +// Function prototype/forward declaration for ISR. +void atint(); + +/** EINT3_IRQHandler + */ +extern "C" void EINT3_IRQHandler (void) { + + // The "event" is connected to pin p10 which is LPC1768 P0_1 + // so lets trap that and ignore all other GPIO interrupts. + // Test for IRQ on Port0. + if (LPC_GPIOINT->IntStatus & 0x1) { + // If P0_1/p10 rises, call atint() + if (LPC_GPIOINT->IO0IntStatR & (1 << 1)) atint(); + } + + // Clear this and all other possible GPIO generated interrupts as they don't concern us. + LPC_GPIOINT->IO2IntClr = (LPC_GPIOINT->IO2IntStatR | LPC_GPIOINT->IO2IntStatF); + LPC_GPIOINT->IO0IntClr = (LPC_GPIOINT->IO0IntStatR | LPC_GPIOINT->IO0IntStatF); +} + +void event_irq_init(void) { + // Use macro to set p10 as an input. + p10_AS_INPUT; + // Enable P0_1/p10 for rising edge interrupt generation. + LPC_GPIOINT->IO0IntEnR |= (1UL << 1); + // Enable the interrupt. + NVIC_EnableIRQ(EINT3_IRQn); +} + +void atint() { + count = t.read(); + t.reset(); +} + +void attim() { + LED1_TOGGLE; // Use macro instead of led =!led; + if (count!=oldcount) { + oldcount = count; + rev= (60/count); + if (rev >= 15000) // Reduce resolution to 100 rpm + rev = (rev/100)*100; + else if (rev >= 1000) // Reduce resolution to 10 rpm + rev = (rev/10)*10; + lcd.cls(); + lcd.printf("U/m %5d ",rev); + } +} + +int main() { + count = 0; + lcd.printf("Revolution counter",rev); + wait(0.5); + lcd.cls(); + timer.attach(&attim,1); + event_irq_init(); + t.start(); + while (1) { + } +} \ No newline at end of file