Uploading Legacy Material

Power Electronics/Legacy Material/Program for SPWM Inverter.cpp

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+// This program outputs a 50Hz complimentary Sinusoidal PWM signal on PA8 and PB13.
+// The switching speed is 10kHz.  The program uses a mix of mbed functions and
+// direct register writes.  It makes use of a lookup table generated in Octave (Thanks Richard Hayes)
+// and interrupts to update the duty cycle.
+// A potentiometer is attached to A0 and this can be used to control the amplitude modulation index.
+// Useful reference: http://stm32.kosyak.info/doc/index.html
+#include "mbed.h"
+// Define some bitmasks
+#define BIT0 (1 << 0)
+#define BIT1 (1 << 1)
+#define BIT2 (1 << 2)
+#define BIT3 (1 << 3)
+#define BIT4 (1 << 4)
+#define BIT5 (1 << 5)
+#define BIT6 (1 << 6)
+#define BIT7 (1 << 7)
+#define BIT8 (1 << 8)
+#define BIT9 (1 << 9)
+#define BIT10 (1 << 10)
+#define BIT11 (1 << 11)
+#define BIT12 (1 << 12)
+#define BIT13 (1 << 13)
+#define BIT14 (1 << 14)
+#define BIT15 (1 << 15)
+#define BIT16 (1 << 16)
+#define BIT17 (1 << 17)
+#define BIT18 (1 << 18)
+#define BIT19 (1 << 19)
+#define BIT20 (1 << 20)
+#define BIT21 (1 << 21)
+#define BIT22 (1 << 22)
+#define BIT23 (1 << 23)
+#define BIT24 (1 << 24)
+#define BIT25 (1 << 25)
+#define BIT26 (1 << 26)
+#define BIT27 (1 << 27)
+#define BIT28 (1 << 28)
+#define BIT29 (1 << 29)
+#define BIT30 (1 << 30)
+#define BIT31 (1 << 31)
+DigitalOut myled(LED1);
+const int duties[]={\
+    50,51,53,54,56,57,59,60,62,63,65,66,68,69,71,72,74, \
+    75,76,78,79,80,81,83,84,85,86,87,88,89,90,91,92,93,\
+    93,94,95,95,96,97,97,98,98,98,99,99,99,99,99,99,100,\
+    99,99,99,99,99,99,98,98,98,97,97,96,95,95,94,93,93,\
+    92,91,90,89,88,87,86,85,84,83,81,80,79,78,76,75,74,\
+    72,71,69,68,66,65,63,62,60,59,57,56,54,53,51,49,48,\
+    46,45,43,42,40,39,37,36,34,33,31,30,28,27,25,24,23,\
+    21,20,19,18,16,15,14,13,12,11,10,9,8,7,6,6,5,4,4,3,\
+    2,2,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,2,2,3,4,4,\
+    5,6,6,7,8,9,10,11,12,13,14,15,16,18,19,20,21,23,24,\
+    25,27,28,30,31,33,34,36,37,39,40,42,43,45,46,48\    
+};
+/*
+Pin mappings for Timer 1 (the advanced timer with deadtime)
+From: https://developer.mbed.org/users/mbed_official/code/mbed-src/file/a11c0372f0ba/targets/hal/TARGET_STM/TARGET_STM32F1/TARGET_NUCLEO_F103RB/PeripheralPins.c
+    {PA_8,  PWM_1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, 0)}, // TIM1_CH1 - Default
+    {PA_9,  PWM_1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, 0)}, // TIM1_CH2 - Default
+    {PA_10, PWM_1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, 0)}, // TIM1_CH3 - Default
+    {PB_13, PWM_1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, 0)}, // TIM1_CH1N - Default
+    {PB_14, PWM_1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, 0)}, // TIM1_CH2N - Default
+    {PB_15, PWM_1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, 0)}, // TIM1_CH3N - Default
+ 
+*/
+// Use mbed to configure the relevant pins as PWM outputs;
+PwmOut      PhaATop(PA_8);    
+PwmOut      PhaABtm(PB_13);  // This should be the complement of PA_8  
+AnalogIn    Pot(A0);
+volatile float PotValue;
+void init(void);
+int main() {    
+
+    init();
+    while(1) {
+        //myled = 1; // LED is ON
+        wait(0.2); // 200 ms
+        //myled = 0; // LED is OFF
+        wait(0.2); // 1 sec        
+        PotValue = Pot;
+    }
+}
+
+int ScaleDuty(int Duty,float factor)
+{
+    float ScaledDuty = Duty;
+    ScaledDuty = (ScaledDuty - 50) * factor;
+    ScaledDuty = ScaledDuty + 50;
+    return ScaledDuty;
+}
+int index=0;
+int state = 0;
+void TimerISR()
+{       
+    TIM1->SR &= ~0x3f; // ack the interrupt    
+    TIM1->CCR1=duties[index++]*1; // get the next duty
+    if (index > 199)
+    {        
+        index = 0;   
+        myled = state;  // generate a trigger signal for a scope
+        state = ~state;
+    }
+}
+void init()
+{
+
+    RCC->APB2ENR |= BIT2+BIT3;  // enable GPIOA and GPIOB    
+    RCC->APB2ENR |= BIT11;      // enable TIM1
+
+    GPIOA->CRH |= BIT3+BIT0;    // PA8 output, alternate function
+    GPIOB->CRH |= BIT23+BIT20;  // PB13 output, alternate function
+
+    TIM1->CR2 = 0;
+    TIM1->DIER = BIT0; // Want update interrupt
+    NVIC_SetVector(TIM1_UP_IRQn,(uint32_t) TimerISR);   
+    NVIC_EnableIRQ(TIM1_UP_IRQn);
+    TIM1->SR = 0;      // Clear flags.
+    TIM1->CCMR1= BIT6+BIT5+BIT4;
+    TIM1->CCER = BIT2+BIT0;
+    TIM1->ARR = 100;  // 1MHz = base clock freq.  Divide by 100 to get 10kHz.
+    TIM1->CCR1 = 10;  // Low inital duty
+    TIM1->CR1 |= BIT0; //enable counter
+     __enable_irq();   // enable interrupts
+
+}