No.9 Robotics / Mbed 2 deprecated Robotics_Servo_control

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Dependencies:   mbed

Fork of Robotics_Lab_Servo by LDSC_Robotics

main.cpp@6:52f6c4d57d74, 2016-03-10 (annotated)

Committer:
dg0704
Date:
Thu Mar 10 07:26:03 2016 +0000
Revision:
6:52f6c4d57d74
Parent:
5:d495dc55f709
Child:
7:db4ddfc0cf4e
PI

Who changed what in which revision?

UserRevisionLine numberNew contents of line
YCTung 0:564d77fcaa70 1 /*LAB_SERVO*/
YCTung 0:564d77fcaa70 2 #include "mbed.h"
YCTung 0:564d77fcaa70 3
YCTung 0:564d77fcaa70 4 //The number will be compiled as type "double" in default
YCTung 0:564d77fcaa70 5 //Add a "f" after the number can make it compiled as type "float"
YCTung 1:3b6c9baa7d0c 6 #define Ts 0.01f //period of timer1 (s)
YCTung 2:a3c64321e9c2 7 #define Kp 0.053f
YCTung 2:a3c64321e9c2 8 #define Ki 0.013f
YCTung 0:564d77fcaa70 9
dg0704 5:d495dc55f709 10 PwmOut pwm1(D7);
dg0704 5:d495dc55f709 11 PwmOut pwm1n(D11);
YCTung 0:564d77fcaa70 12
YCTung 0:564d77fcaa70 13 AnalogIn adc(A2);//Temporary usage
YCTung 0:564d77fcaa70 14
YCTung 0:564d77fcaa70 15 //LED1 = D13 = PA_5 (LED on Nucleo board)
YCTung 0:564d77fcaa70 16 DigitalOut led1(LED1);
YCTung 0:564d77fcaa70 17 DigitalOut led2(D12);
YCTung 0:564d77fcaa70 18
dg0704 4:facfa2ac9a59 19 // timer variables
YCTung 0:564d77fcaa70 20 Ticker timer1;
dg0704 4:facfa2ac9a59 21 int timer1_counter;
YCTung 1:3b6c9baa7d0c 22 void timer1_interrupt(void);
YCTung 0:564d77fcaa70 23
YCTung 1:3b6c9baa7d0c 24 void init_TIMER(void);
YCTung 0:564d77fcaa70 25 void init_IO(void);
YCTung 0:564d77fcaa70 26 void init_PWM(void);
YCTung 1:3b6c9baa7d0c 27 void flash(void);
YCTung 0:564d77fcaa70 28
YCTung 1:3b6c9baa7d0c 29 //Variable(s) for PI controller
YCTung 2:a3c64321e9c2 30 float angle_ref = 0.0; //unit in degree(s), range +-90 degrees
YCTung 2:a3c64321e9c2 31 float angle_read= 0.0;
YCTung 2:a3c64321e9c2 32 float angle_check;
YCTung 0:564d77fcaa70 33 float err = 0.0;
YCTung 0:564d77fcaa70 34 float ierr = 0.0;
YCTung 0:564d77fcaa70 35 float PI_out = 0.0;
YCTung 0:564d77fcaa70 36 float pwm1_duty = 0.5;
YCTung 0:564d77fcaa70 37
YCTung 1:3b6c9baa7d0c 38 int main (void)
YCTung 1:3b6c9baa7d0c 39 {
YCTung 1:3b6c9baa7d0c 40 init_IO();
YCTung 1:3b6c9baa7d0c 41 init_PWM();
YCTung 1:3b6c9baa7d0c 42 init_TIMER();
YCTung 1:3b6c9baa7d0c 43 while(1)
YCTung 1:3b6c9baa7d0c 44 {
dg0704 4:facfa2ac9a59 45 if(timer1_counter == 100)
dg0704 4:facfa2ac9a59 46 {
dg0704 4:facfa2ac9a59 47 timer1_counter = 0;
dg0704 4:facfa2ac9a59 48 angle_ref += 15;
dg0704 4:facfa2ac9a59 49 if (angle_ref == 45)
dg0704 4:facfa2ac9a59 50 break;
dg0704 4:facfa2ac9a59 51 }
YCTung 1:3b6c9baa7d0c 52 }
YCTung 1:3b6c9baa7d0c 53 }
YCTung 1:3b6c9baa7d0c 54
YCTung 0:564d77fcaa70 55 void timer1_interrupt(void)
YCTung 0:564d77fcaa70 56 {
dg0704 4:facfa2ac9a59 57 timer1_counter ++;
dg0704 4:facfa2ac9a59 58
YCTung 2:a3c64321e9c2 59 angle_read = (adc.read() - 0.45f) / 0.48f * 180.0f; //0.21 ~ 0.69 respect to -90 ~ +90 degree
YCTung 2:a3c64321e9c2 60 angle_check = angle_read;
YCTung 0:564d77fcaa70 61
YCTung 1:3b6c9baa7d0c 62 //////code for PI control//////
dg0704 3:71a807b38a3e 63 err = angle_ref - angle_read;
dg0704 6:52f6c4d57d74 64 ierr += err;
dg0704 6:52f6c4d57d74 65 PI_out = Kp * err + Ki * 0.01f*(ierr - err);
YCTung 2:a3c64321e9c2 66
YCTung 0:564d77fcaa70 67 ////////////
YCTung 0:564d77fcaa70 68 if(PI_out >= 0.5f)PI_out = 0.5;
YCTung 0:564d77fcaa70 69 else if(PI_out <= -0.5f)PI_out = -0.5;
YCTung 0:564d77fcaa70 70 pwm1_duty = PI_out + 0.5f;
YCTung 2:a3c64321e9c2 71 if(angle_check > 100.0f || angle_check < -100.0f)pwm1_duty = 0.5;
YCTung 0:564d77fcaa70 72 pwm1.write(pwm1_duty);
dg0704 3:71a807b38a3e 73 TIM1->CCER |= 0x4; //enable ch1 complementary output
dg0704 3:71a807b38a3e 74
YCTung 0:564d77fcaa70 75 }
YCTung 0:564d77fcaa70 76
YCTung 0:564d77fcaa70 77 void init_TIMER(void)
YCTung 0:564d77fcaa70 78 {
YCTung 0:564d77fcaa70 79 timer1.attach_us(&timer1_interrupt, 10000);//10ms interrupt period (100 Hz)
dg0704 4:facfa2ac9a59 80 timer1_counter = 0;
YCTung 0:564d77fcaa70 81 }
YCTung 0:564d77fcaa70 82
YCTung 0:564d77fcaa70 83 void init_IO(void)
YCTung 0:564d77fcaa70 84 {
dg0704 4:facfa2ac9a59 85 angle_ref = -45;
YCTung 0:564d77fcaa70 86 }
YCTung 0:564d77fcaa70 87
YCTung 0:564d77fcaa70 88 void init_PWM(void)
YCTung 0:564d77fcaa70 89 {
YCTung 0:564d77fcaa70 90 pwm1.period_us(50);
YCTung 0:564d77fcaa70 91 pwm1.write(0.5);
YCTung 0:564d77fcaa70 92 TIM1->CCER |= 0x4;
YCTung 0:564d77fcaa70 93 }
YCTung 0:564d77fcaa70 94
YCTung 0:564d77fcaa70 95 void flash(void)
YCTung 0:564d77fcaa70 96 {
YCTung 0:564d77fcaa70 97 led1 = !led1;
YCTung 0:564d77fcaa70 98 }