Diff: main.cpp

Revision:

0:dc5c88c2dd20

Child:

1:f97adef77f4b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Feb 03 18:18:22 2017 +0000
@@ -0,0 +1,130 @@
+///setup code for encoder on pins PA0 and PA1 (A0 and A1)///
+
+#include "mbed.h"
+#include "time.h"
+
+InterruptIn button(USER_BUTTON);
+PwmOut pwm(D5);//do not use D3
+DigitalOut a(D2);
+DigitalOut b(D4);
+
+int endcount, startcount;
+double time_between_readings;
+double velocity;
+
+int cpr = 900;  // Encoder counts per revolution.  Change to match your encoder 
+
+AnalogIn motorVoltage(A4); //hook up to high voltage motor terminal with capacitor. this doesn't share a common ground though hmm... can I hook up battery ground
+AnalogIn motorCurrent(A5); //hook up to Vout on current sensor
+Serial pc(USBTX, USBRX);
+DigitalOut green(LED2);
+
+
+void EncoderInitialise(void) {
+    // configure GPIO PA0 & PA1 as inputs for Encoder
+    RCC->AHB1ENR |= 0x00000001;  // Enable clock for GPIOA
+ 
+    GPIOA->MODER   |= GPIO_MODER_MODER0_1 | GPIO_MODER_MODER1_1 ;           //PA0 & PA1 as Alternate Function   /*!< GPIO port mode register,               Address offset: 0x00      */
+    GPIOA->OTYPER  |= GPIO_OTYPER_OT_0 | GPIO_OTYPER_OT_1 ;                 //PA0 & PA1 as Inputs               /*!< GPIO port output type register,        Address offset: 0x04      */
+    GPIOA->OSPEEDR |= 0x00000011;//|= GPIO_OSPEEDER_OSPEEDR0 | GPIO_OSPEEDER_OSPEEDR1 ;     // Low speed                        /*!< GPIO port output speed register,       Address offset: 0x08      */
+    GPIOA->PUPDR   |= GPIO_PUPDR_PUPDR0_1 | GPIO_PUPDR_PUPDR1_1 ;           // Pull Down                        /*!< GPIO port pull-up/pull-down register,  Address offset: 0x0C      */
+    GPIOA->AFR[0]  |= 0x00000011 ;                                          //  AF01 for PA0 & PA1              /*!< GPIO alternate function registers,     Address offset: 0x20-0x24 */
+    GPIOA->AFR[1]  |= 0x00000000 ;                                          //                                  /*!< GPIO alternate function registers,     Address offset: 0x20-0x24 */
+   
+    // configure TIM2 as Encoder input
+    RCC->APB1ENR |= 0x00000001;  // Enable clock for TIM2
+ 
+    TIM2->CR1   = 0x0001;       // CEN(Counter Enable)='1'     < TIM control register 1
+    TIM2->SMCR  = 0x0003;       // SMS='011' (Encoder mode 3)  < TIM slave mode control register
+    TIM2->CCMR1 = 0x0101;       // CC1S='01' CC2S='01'         < TIM capture/compare mode register 1
+    TIM2->CCMR2 = 0x0000;       //                             < TIM capture/compare mode register 2
+    TIM2->CCER  = 0x0011;       // CC1P CC2P                   < TIM capture/compare enable register
+    TIM2->PSC   = 0x0000;       // Prescaler = (0+1)           < TIM prescaler
+    TIM2->ARR   = cpr;          // reload at cpr               < TIM auto-reload register
+    TIM2->CNT = 0x0000;         //reset the counter before we use it  
+}
+
+
+//Zero encoder count//
+void ZeroEncoder() {
+    TIM2->CNT=0 ; //reset timer count to zero
+}
+
+int GetCounts(void) {
+    int count = TIM2->CNT;  //Read the timer count register
+    return count;
+    }
+    
+void pressed() {
+    float pwm_float = pwm.read();
+    int pwmV = (int)(100*pwm_float);
+    printf("pwm2: %d\n\r",pwmV);
+    if(pwmV == 0){
+        pwm.write(0.1);
+    } else if (pwmV == 10){
+        pwm.write(0.2);
+    } else if (pwmV == 20){
+        pwm.write(0.5);
+    } else if (pwmV == 50){
+        pwm.write(1.0);
+    } else if (pwmV == 100){
+        pwm.write(0.0);
+    }         
+}
+
+
+
+int main() {
+    
+    EncoderInitialise();
+    clock_t start;
+    clock_t end = clock();
+    int ticks;
+    a=1; b=0; pwm.write(0);
+    button.fall(&pressed);
+    double updatePeriod = 0.01; /* must select carefully */
+    double publishFrequency = 0.1; /* seconds. rate to publish to matlab */
+    double samplesPerPublish = (int)(publishFrequency/updatePeriod); /*sample and average then publish for filtering*/
+    int publishCounter = 1;
+    double filterRatio = 0.3;
+
+    while(1) {
+        
+        wait(updatePeriod);
+        start = end;
+        end = clock();        
+        time_between_readings = ((double)(end - start)) / CLOCKS_PER_SEC;
+        startcount = endcount;
+        endcount = GetCounts();       
+        ticks = endcount-startcount;
+        if(abs(ticks)>cpr/2) /***** for rollover case: *****/
+        { ticks = ((ticks<0)-(ticks>0))*(cpr-abs(ticks)); }
+        velocity = filterRatio*((double)ticks)/cpr/time_between_readings + (1-filterRatio)*velocity; /* with filtering*/
+        if(pc.readable())
+            {
+            char abrahamsCommand = pc.getc();
+            if(abrahamsCommand == '1'){ green = 1; }
+            if(abrahamsCommand == '0'){ green = 0; }
+            }
+            
+        printf("%f,%f,%f\n", motorCurrent.read(), motorVoltage.read(), velocity);
+            
+//        ---averaging filter---    
+        //if(publishCounter == samplesPerPublish){
+//            printf("%f,%f,%f\n", motorCurrent.read(), motorVoltage.read(), velocity);
+//            publishCounter = 1;
+//        }
+//        publishCounter++;
+        
+    }
+    
+    
+}
+
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