Diff: motor.h

Revision:

0:009e84d7af32

Child:

2:b30a467e90d3

diff -r 000000000000 -r 009e84d7af32 motor.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/motor.h	Fri Oct 19 10:57:39 2018 +0000
@@ -0,0 +1,56 @@
+#pragma once
+
+#include "mbed.h"
+#include "FastPWM.h"
+#include "MODSERIAL.h"
+#include "QEI.h"
+
+#include "pid.h"
+
+const float PI = 3.14159265359;
+
+// Amount of motor encoder pulses per rotation. When using X4 encoding.
+const int PULSES_PER_ROTATION = 6533;
+
+const double MOTOR_THRESHOLD_RPS = 0.1; // Rad/s under which we send 0 to the motor, to prevent it from jittering around.
+const double MOTOR_STALL_PWM = 0.45; // PWM fraction above which the motor starts to move.
+
+class Motor {
+    /// Rotates a motor to a given angle using PID control.
+    /// Sets the pwm frequency to 60 HZ.
+private:
+    Ticker motor_ticker;
+
+    FastPWM pwm_out;
+    DigitalOut dir_out;
+    QEI encoder;
+    PID pid;
+    
+    double target_angle;
+    
+    // For debugging purposes;
+    Serial* pc;
+    int printcount;
+    float pid_period;
+public:
+    // Initializes the motor with the two driver pins, and the two encoder pins.
+    Motor(PinName pwm_pin, PinName dir_pin, PinName encoder_a, PinName encoder_b, Serial* pc);
+    // Set the angle the motor needs to rotate to. In radians.
+    void set_target_angle(double angle);
+    void set_pid_k_values(double k_p, double k_i, double k_d);
+    // Starts the motor controller with the specified update period.
+    void start(float period);
+    
+    // Returns the current angle of the motor.
+    double get_current_angle();
+    
+private:
+    void update();
+    // Updates the motor with the given speed.
+    // The speed can be both positive and negative, in the range [-1, 1].
+    void update_motor_speed(double speed);
+    double encoder_pulses_to_radians(int pulses);
+    // Converts radians/s values into PWM values for motor controll.
+    // Both positive and negative values.
+    double radians_per_second_to_pwm(double rps);
+};
\ No newline at end of file