Cortex Challenge Team
PWM with regular digital IO and with digital pin that supports PWM generation
Dependencies: mbed
Diff: main.cpp
- Revision:
- 0:ee9aab897b59
- Child:
- 1:56cc90ae5080
diff -r 000000000000 -r ee9aab897b59 main.cpp
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Mon Apr 20 15:07:18 2015 +0000
@@ -0,0 +1,147 @@
+/**********************************************************************************
+* @file main.cpp
+* @author Petr Douša
+* @version V1.0
+* @date 20-April-2015
+* @brief This program use digital output and regular PWM output to modulate PWM
+***********************************************************************************/
+
+/**********************************************************************************/
+/* Table of PWM pins on Nucleo F303 (LQFP64) */
+/**********************************************************************************/
+/* LQFP64 pin | Nucleo pin | ST Pin | PWM number | Channel */
+/* 15 | A1 | PA_1 | PWM15 | 1 */
+/* 26 | A3 | PB_0 | PWM1 | 2 */
+/* 9 | A4 | PC_1 | PWM1 | 2 */
+/* 8 | A5 | PC_0 | PWM1 | 1 */
+/* 17 | D0 | PA_3 | PWM15 | 2 */
+/* 16 | D1 | PA_2 | PWM15 | 1 */
+/* 43 | D2 | PA_10 | PWM1 | 3 */
+/* 55 | D3 | PB_3 | PWM8 | 1 */
+/* 57 | D4 | PB_5 | PWM17 | 1 */
+/* 56 | D5 | PB_4 | PWM16 | 1 */
+/* 41 | D7 | PA_8 | PWM1 | 1 */
+/* 42 | D8 | PA_9 | PWM1 | 2 */
+/* 38 | D9 | PC_7 | PWM3 | 2 */
+/* 58 | D10 | PB_6 | PWM16 | 1 */
+/* 23 | D11 | PA_7 | PWM15 | 2 */
+/* 22 | D12 | PA_6 | PWM15 | 1 */
+/* 62 | D14 | PB_9 | PWM17 | 1 */
+/* 61 | D15 | PB_8 | PWM16 | 1 */
+/* 46 | | PA_13 | PWM16 | 1 */
+/* 49 | | PA_14 | PWM8 | 2 */
+/* 59 | | PB_7 | PWM17 | 1 */
+/* 2 | | PC_13 | PWM1 | 1 */
+/* 10 | | PC_2 | PWM1 | 3 */
+/* 11 | | PC_3 | PWM1 | 4 */
+/* 40 | | PC_9 | PWM3 | 4 */
+/* 39 | | PC_8 | PWM3 | 3 */
+/* 37 | | PC_6 | PWM3 | 1 */
+/* 45 | | PA_12 | PWM16 | 1 */
+/* 44 | | PA_11 | PWM1 | 4 */
+/* 27 | | PB_1 | PWM1 | 3 */
+/* 36 | | PB_15 | PWM17 | 1 */
+/* 35 | | PB_14 | PWM16 | 1 */
+/**********************************************************************************/
+
+/* Includes ----------------------------------------------------------------------*/
+#include "mbed.h"
+
+/* Defines -----------------------------------------------------------------------*/
+
+/* Function prototypes -----------------------------------------------------------*/
+void toggleOff(void);
+
+/* Variables ---------------------------------------------------------------------*/
+int on_delay = 0;
+int off_delay = 0;
+
+//mbed - initialization of peripherals
+Timeout timer; // timer use with digital IO
+DigitalOut my_pwm(LED1); // digital IO used by pwm_io function
+PwmOut real_pwm(PA_8); // regular PWM output
+
+/* Functions----------------------------------------------------------------------*/
+
+/*******************************************************************************
+* Function Name : toggleOn.
+* Description : Set high on digital pin and set and start timer.
+* Input : None.
+* Output : None.
+* Return : None.
+*******************************************************************************/
+void toggleOn(void)
+{
+ my_pwm = 1;
+ timer.attach_us(toggleOff, on_delay);
+}
+
+/*******************************************************************************
+* Function Name : toggleOff.
+* Description : Set low on digital pin and set and start timer.
+* Input : None.
+* Output : None.
+* Return : None.
+*******************************************************************************/
+void toggleOff(void)
+{
+ my_pwm = 0;
+ timer.attach_us(toggleOn, off_delay);
+}
+
+/*******************************************************************************
+* Function Name : pwm_io.
+* Description : Set variables and start PWM on digital output.
+* Input : p_us: signal period in micro_seconds ,dc: signal duty-cycle (0.0 to 1.0) .
+* Output : on_delay: time to be digital output on high ,off_delay: time to be digital output on low: .
+* Return : None.
+*******************************************************************************/
+void pwm_io(int p_us, float dc)
+{
+ timer.detach(); // shutdown timer
+ if ((p_us == 0) || (dc == 0)) { // if duty-cycle is 0
+ my_pwm = 0; // set low regular IO to low
+ return;
+ }
+ if (dc >= 1) { // if duty-cycle is 1 and more
+ my_pwm = 1; // set high regular IO to low
+ return;
+ }
+ on_delay = (int)(p_us * dc); // calculate time to be digital output on high and low
+ off_delay = p_us - on_delay;
+ toggleOn(); // call function toggleOn to start PWM
+}
+
+/***********************************************************************************
+* Function Name : main.
+* Description : Main routine.
+* Input : None.
+* Output : None.
+* Return : None.
+***********************************************************************************/
+int main()
+{
+ double a=0; // variable to set duty-cycle
+
+ real_pwm.period_us(2000); // set period of real PWM to 2 milliseconds
+ real_pwm.write(a); // set duty-cycle as it is in variable a (0 at this point)
+
+
+ pwm_io(2000, a); // set period of digital IO PWM to 2 ms and duty-cycle as in variable a (0 at this point)
+
+
+ while(1) { // main cykl of program
+
+ if(a>=1) { // if variable is grater then 1 set it 0 else attributable 0.01
+ a=0;
+ } else {
+ a=a+0.01;
+ }
+
+ real_pwm.write(a); // set duty-cycle of real PWM as as it is in variable a
+
+ pwm_io(2000, a); // set duty-cycle of digital IO PWM as as it is in variable a and period to 2 ms
+
+ wait(0.05); // wait some time in milliseconds
+ }
+}