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) {
+    }
+}
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