Diff: main.cpp

Revision:

0:8de789e82743

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Oct 20 13:20:44 2010 +0000
@@ -0,0 +1,118 @@
+// Phase-shifted PWM Test Code
+// 
+// Attempt to run two PWM outputs with 180° phase shifting
+// Version x.x
+// Created by Wayne Chin
+// October 15, 2010
+
+#include "mbed.h"
+
+#define TRUE 1
+#define FALSE 0
+
+DigitalOut led1(LED1);
+DigitalOut led2(LED2);
+DigitalOut led3(LED3);
+DigitalOut led4(LED4);
+
+Ticker pwmramp1;
+Ticker pwmramp2;
+int duty1; // Duty cycle in integer %
+int duty2; // Duty cycle in integer %
+int PWMclock; // PWM clock = system clock / 4
+int PWMrate; // Use to calculate PWM rate (period)
+
+Serial pc(USBTX, USBRX); // tx, rx
+
+void pwmupdate1()
+{
+    int PWMwidth, PWMhalf, PWMrising, PWMfalling;
+    if (duty1++ > 100) duty1 = 0; // Clamp at 100% pulsewidth
+    PWMwidth = (duty1 * PWMrate) / 100;
+    PWMhalf = PWMwidth / 2;
+    PWMrising = PWMrate - PWMhalf;
+    PWMfalling = PWMhalf;
+    LPC_PWM1->MR3 = PWMrising; // Set rising edge
+    LPC_PWM1->MR4 = PWMfalling; // Set falling edge
+    LPC_PWM1->LER |= 0x18; // Enable PWM Match 3 & 4 latch
+    led4 = !led4;
+}
+
+void pwmupdate2()
+{
+    int PWMcenter, PWMwidth, PWMhalf, PWMrising, PWMfalling;
+    if (duty2++ > 100) duty2 = 0; // Clamp at 100% pulsewidth
+    PWMcenter = PWMrate / 2;
+    PWMwidth = (duty2 * PWMrate) / 100;
+    PWMhalf = PWMwidth / 2;
+    PWMrising = PWMcenter - PWMhalf;
+    PWMfalling = PWMcenter + PWMhalf;
+    LPC_PWM1->MR5 = PWMrising;
+    LPC_PWM1->MR6 = PWMfalling;
+    LPC_PWM1->LER |= 0x60; // Enable PWM Match 5 & 6 latch
+    led2 = !led2;
+}
+
+int main() 
+{
+    /****** Program Starts Here *******/
+    pc.baud(19200);
+    pc.printf("\n\rConnected to mBed...\r\n");
+    // Initialize variables
+    duty1 = 0;
+    duty2 = 0;
+    
+    printf("SystemCoreClock = %d Hz\r\n", SystemCoreClock);
+    // Verify power control for peripherals register
+    printf("PCLKSEL0: %x\n\r", LPC_SC->PCLKSEL0);          // Leave at CCLK/4
+    PWMclock = SystemCoreClock / 4;
+    PWMrate = PWMclock / 15000;                            // 15kHz
+    printf("PWMrate: %x\n\r", PWMrate);
+    //printf("PINSEL4: %x\n\r", LPC_PINCON->PINSEL4);        // Comes up as GPIO
+    LPC_PINCON->PINSEL4 |= 0x00000040;                     // Set P2.3 for PWM1.4
+    LPC_PINCON->PINSEL4 |= 0x00000400;                     // Set P2.5 for PWM1.6
+    printf("PINSEL4: %x\n\r", LPC_PINCON->PINSEL4);
+    // Set up count control register
+    printf("PWM1CTCR: %x\n\r", LPC_PWM1->CTCR); // Should already come up in timer mode
+    // Set up match control register
+    printf("PWM1MCR: %x\n\r", LPC_PWM1->MCR);
+    //LPC_PWM1->MCR |= 0x00002000; // Reset PWM4 on match - do not use
+    //LPC_PWM1->MCR |= 0x00080000; // Reset PWM6 on match - do not use
+    LPC_PWM1->MCR |= 0x00000002; // Reset PWM0 on match
+    printf("PWM1MCR: %x\n\r", LPC_PWM1->MCR);
+    // Set up match registers
+    LPC_PWM1->MR0 = PWMrate; // Set MR0 (PWM rate)
+    LPC_PWM1->MR3 = 0x000; // Reset MR3
+    LPC_PWM1->MR4 = 0x320; // Reset MR4
+    LPC_PWM1->MR5 = 0x160; // Reset MR5
+    LPC_PWM1->MR6 = 0x480; // Reset MR6
+    printf("PWM1MR0,3,4,5,6: %x %x %x %x %x\n\r", LPC_PWM1->MR0, LPC_PWM1->MR3, LPC_PWM1->MR4, LPC_PWM1->MR5, LPC_PWM1->MR6);
+    // Set up latch enable register
+    printf("PWM1LER: %x\n\r", LPC_PWM1->LER);
+    LPC_PWM1->LER |= 0x08; // Enable PWM Match 3 latch
+    LPC_PWM1->LER |= 0x10; // Enable PWM Match 4 latch
+    LPC_PWM1->LER |= 0x20; // Enable PWM Match 5 latch
+    LPC_PWM1->LER |= 0x40; // Enable PWM Match 6 latch
+    printf("PWM1LER: %x\n\r", LPC_PWM1->LER);
+    // Set up PWM control register
+    printf("PWM1PCR: %x\n\r", LPC_PWM1->PCR);
+    LPC_PWM1->PCR |= 0x00000010; // Select double edge PWM for PWM4
+    LPC_PWM1->PCR |= 0x00000040; // Select double edge PWM for PWM6
+    LPC_PWM1->PCR |= 0x00001000; // Enable PWM4
+    LPC_PWM1->PCR |= 0x00004000; // Enable PWM6
+    printf("PWM1PCR: %x\n\r", LPC_PWM1->PCR);
+    // Set up timer control register
+    printf("PWM1TCR: %x\n\r", LPC_PWM1->TCR);
+    LPC_PWM1->TCR |= 0x08; // Enable PWM mode
+    LPC_PWM1->TCR |= 0x01; // Enable counter
+    printf("PWM1TCR: %x\n\r", LPC_PWM1->TCR);
+
+    // Set up timeout calls
+    pwmramp1.attach_us(&pwmupdate1, 250000); // setup pwmramp1 to call pwmupdate after 250 ms
+    pwmramp2.attach_us(&pwmupdate2, 500000); // setup pwmramp2 to call pwmupdate after 500 ms
+
+    while (1)
+    {
+        
+    }//while
+}//main
\ No newline at end of file