Revision 0:e619b6823668, committed 2014-01-28

Comitter:

garyr

Date:

Tue Jan 28 17:01:19 2014 +0000

Commit message:

First working version

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Timer2.cpp	Tue Jan 28 17:01:19 2014 +0000
@@ -0,0 +1,53 @@
+
+/*
+    This counter establishes the measurent interval.
+    MAT2.0 (P8) is set when the interval has elapsed.
+
+    This code generates timed intervals T = <prescale> * 100 ms.
+    mbed pin 8 goes high at the beginning of the interval and returns to zero at the end.
+    The interrupt occurs at the end of the interval.
+*/
+#include "TARGET_LPC1768/LPC17xx.h"
+#include "mbed.h"
+#include "Timer2.h"
+
+funcptr timer2ISR;
+
+void Timer2_IRQHandler(void)
+{
+    if (LPC_TIM2->IR & 1)           // MR0 interrupt
+    {
+        LPC_TIM2->IR = 1;           // clear the interrupt
+        if (timer2ISR)
+            timer2ISR();
+    }
+}
+
+void Timer2_init(funcptr callback)
+{
+    timer2ISR = callback;
+    LPC_SC->PCONP |= (1<<22);           // Power on the Timer2
+    LPC_SC->PCLKSEL1 &= ~(3<<12);
+    LPC_SC->PCLKSEL1 |= (1<<12);        // Select  CCLK for Timer2
+    LPC_PINCON->PINSEL0 &=~(3<<12);
+    LPC_PINCON->PINSEL0 |= (3<<12);     // Connect MAT2.0 to mbed P8
+    LPC_PINCON->PINMODE0 &=~(3<<12);
+    LPC_PINCON->PINMODE0 |= (2<<12);    // no pull-p or pull-down
+    if (callback)
+    {
+        NVIC_SetPriority(TIMER2_IRQn, 10);
+        NVIC_SetVector(TIMER2_IRQn, (uint32_t)&Timer2_IRQHandler);
+        NVIC_EnableIRQ(TIMER2_IRQn);
+    }
+}
+void Timer2_start(int prescale)
+{
+    LPC_TIM2->TCR = 2;                  // Reset the timer and prescale counters on next PCLK
+    LPC_TIM2->MR0 = CLOCK/10;           // Set the Timer2 match register for 100 ms resolution
+    LPC_TIM2->CTCR = 0;                 // Timer2 is incremented when the prescale register == 0
+    LPC_TIM2->PR = prescale;            // Update prescale register
+    LPC_TIM2->MCR = 3;                  // Interrupt on MR0 and reset
+    LPC_TIM2->EMR = (3<<4)|1;           // Toggle MAT2.0 when match occurs.
+    LPC_TIM2->TCR = 1;                  // Enable Timer2
+    LPC_TIM3->TCR = 1;                  // Enable Timer3
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Timer2.h	Tue Jan 28 17:01:19 2014 +0000
@@ -0,0 +1,12 @@
+#ifndef __TIMER2_H
+#define __TIMER2_H
+
+#define CLOCK   96000000
+
+typedef void (*funcptr)(void);
+extern void Timer2_init(funcptr callback);
+extern void Timer2_start(int prescale);
+
+#endif
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Timer3.cpp	Tue Jan 28 17:01:19 2014 +0000
@@ -0,0 +1,41 @@
+
+// Timer 3 is used by mbed library functions: Ticker, Timer, Wait
+
+#include "TARGET_LPC1768/LPC17xx.h"
+#include "mbed.h"
+#include "Timer3.h"
+
+funcptr3 timer3ISR;
+
+void Timer3_IRQHandler(void)
+{
+#define ICR0    (1<<5)              // CR0 interrupt bit
+int count; 
+    if (LPC_TIM3->IR & ICR0)
+    {
+        count = LPC_TIM3->TC;
+        LPC_TIM3->TCR = 2;         // Disable
+        LPC_TIM3->IR = ICR0;       // clear the interrupt
+        timer3ISR(count);          // return the count
+    }
+}
+
+void Timer3_init(funcptr3 callback)
+{
+    timer3ISR = callback;
+    LPC_SC->PCONP |= (1<<23);           // Power on the Timer3
+    LPC_TIM3->TCR = 2;                  // Reset the timer and prescale counters on next PCLK
+    LPC_SC->PCLKSEL1 &= ~(3<<14);
+    LPC_SC->PCLKSEL1 |= (1<<14);        // Select  CCLK for Timer3
+    LPC_PINCON->PINSEL1 |= (3<<16)|(3<<14);     // Connect CAP3.0 to P15, CAP3.1 to P16
+    LPC_PINCON->PINMODE1 &=~((3<<16)|(3<<14));
+    LPC_PINCON->PINMODE1 |= (2<<16)|(2<<14);    // no pull-p or pull-down
+    LPC_TIM3->CTCR = 1;                 // TC incremented by CAP3.0 (P15) rising edge
+    LPC_TIM3->PR = 0;                   // Set prescale register to zero
+    LPC_TIM3->CCR = 0x30;              // Capture on CAP3.1 (P16) falling edge and interrupt
+    NVIC_SetPriority(TIMER3_IRQn, 9);
+    NVIC_SetVector(TIMER3_IRQn, (uint32_t)&Timer3_IRQHandler);
+    NVIC_EnableIRQ(TIMER3_IRQn);
+    LPC_TIM3->TCR = 2;                  // Disable
+}
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Timer3.h	Tue Jan 28 17:01:19 2014 +0000
@@ -0,0 +1,8 @@
+
+#ifndef H_TIMER3
+#define H_TIMER3
+
+typedef void (*funcptr3)(int);
+extern void Timer3_init(funcptr3);
+
+#endif

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Tue Jan 28 17:01:19 2014 +0000
@@ -0,0 +1,48 @@
+
+#include "mbed.h"
+#include "Timer2.h"
+#include "Timer3.h"
+/*
+    Connect P8 (MAT2.0) to P16 (CAP3.1)
+    Connect external input on P15 (CAP3.0) to PWM output on P26
+*/
+Serial pc(USBTX, USBRX); // tx, rx
+DigitalOut out1(p5), out2(p6);
+PwmOut pw(p26);
+
+int done;
+void Timer3Isr(int count)
+{
+    pc.printf("count=%d\n\r", count);
+    LPC_TIM2->TCR = 2;  // Disable Timer2
+    done = 1;
+}
+
+void Timer2Isr(void)
+{
+    out1 = !out1;
+}
+
+int main(void)
+{
+int prescale;   // Units are 0.1 second.
+
+    out1 = 0;
+    out2 = 0;
+    pw.period_us(10);
+    pw.write(0.5);
+    Timer3_init(Timer3Isr);
+    Timer2_init(Timer2Isr);
+    while(1)
+    {
+        pc.printf("PS: ");
+        pc.scanf("%d", &prescale);      // Interval is <prescale>+1 * 0.1 second.
+        pc.printf("%d\n\r", prescale);
+        done = 0;
+        Timer2_start(prescale);
+        while (!done)
+            out2 = !out2;
+    }
+}
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Tue Jan 28 17:01:19 2014 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/824293ae5e43
\ No newline at end of file