Revision 0:ec69a5b677ed, committed 2014-10-03

Comitter:

jfields

Date:

Fri Oct 03 17:47:43 2014 +0000

Commit message:

final version of timer0 stopwatch

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TextLCD.lib	Fri Oct 03 17:47:43 2014 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/simon/code/TextLCD/#308d188a2d3a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Oct 03 17:47:43 2014 +0000
@@ -0,0 +1,128 @@
+#include "mbed.h"
+#include "TextLCD.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+TextLCD lcd(p15, p16, p17, p18, p19, p20, TextLCD::LCD16x2);
+Serial pc (USBTX, USBRX);
+DigitalOut myled(LED1);
+
+// global vars
+int t [6];
+int run_status = -1;
+
+// functions
+void update_display();
+void update_timer();
+void init_timer0();
+
+int main() {
+    
+    // init timer and display
+    for (int i=0;i<6;i++) t[i]=0;
+    update_display();
+
+    // init timer
+    init_timer0();
+    char input = 'z';
+    
+    while(1) {
+        
+        if ( input == 's') { 
+            run_status = 1;
+            LPC_TIM0->TCR |= 1;
+        }
+        if ( input == 'p') {
+            run_status = 2;
+            LPC_TIM0->TCR &= ~1;
+        }
+        if ( input == 'r') {
+            if (run_status == 2) {
+                for (int i=0; i<6; i++) t[i]=0;
+                update_display();
+            }
+        }
+        
+        input = pc.getc();
+   
+    } 
+}
+
+void update_display() {
+    lcd.printf("%d%d:%d%d:%d%d\n\n",t[5],t[4],t[3],t[2],t[1],t[0]);
+}
+
+void update_timer() {
+// signal = 1 : start
+// signal = 2 : stop
+
+    if (run_status == 1) {
+        
+        // update m0
+        t[0]++;
+
+        // update m1
+        if (t[0] >= 10) {
+            t[0] = 0;
+            t[1]++;
+
+            // update S0
+            if (t[1] >= 10) {
+                t[1] = 0;
+                t[2]++;
+
+                // update S1
+                if (t[2] >= 10) {
+                    t[2] = 0;
+                    t[3]++;
+
+                    // update M0
+                    if (t[3] >= 6) {
+                        t[3]=0;
+                        t[4]++;
+
+                        // update M1
+                        if (t[4] >= 10) {
+                            t[4]=0;
+                            t[5]++;
+                        }
+                    }
+                }
+            }
+        }
+
+        // update display
+        update_display();
+    }        
+    
+    // reset interrupt
+    LPC_TIM0->IR |= 1 << 0;
+}
+
+void init_timer0() {
+
+    //power up TIMER0 (PCONP[1])
+    LPC_SC->PCONP |= 1 << 1;
+
+    // reset and set TIMER0 to timer mode
+    LPC_TIM0->TCR = 0x2;
+    LPC_TIM0->CTCR = 0x0;
+
+    // set no prescaler
+    LPC_TIM0->PR = 0;
+
+    // calculate period (1 interrupt every 1/100 second)
+    uint32_t period = 240000;
+
+    // set match register and enable interrupt
+    LPC_TIM0->MR0 = period;
+    LPC_TIM0->MCR |= 1 << 0;    // interrupt on match
+    LPC_TIM0->MCR |= 1 << 1;    // reset on match
+
+    // enable the vector in the interrupt controller
+    NVIC_SetVector(TIMER0_IRQn, (uint32_t)&update_timer);
+    NVIC_EnableIRQ(TIMER0_IRQn);
+
+    // start the timer
+    LPC_TIM0->TCR = 1;
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Fri Oct 03 17:47:43 2014 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/552587b429a1
\ No newline at end of file