main.cpp

00001 // Workshop 2
00002 #include "mbed.h"
00003 #include "PM2_Libary.h"
00004 
00005 // logical variable main task
00006 bool do_execute_main_task = false;  // this variable will be toggled via the user button (blue button) to or not to execute the main task
00007 
00008 // user button on nucleo board
00009 Timer user_button_timer;            // create Timer object which we use to check if user button was pressed for a certain time (robust against signal bouncing)
00010 InterruptIn user_button(PC_13);     // create InterruptIn interface object to evaluate user button falling and rising edge (no blocking code in ISR)
00011 void user_button_pressed_fcn();     // custom functions which gets executed when user button gets pressed and released, definition below
00012 void user_button_released_fcn();
00013 
00014 // while loop gets executed every main_task_period_ms milliseconds
00015 int main_task_period_ms = 50;   // define main task period time in ms e.g. 50 ms -> main task runns 20 times per second
00016 Timer main_task_timer;          // create Timer object which we use to run the main task every main task period time in ms
00017 
00018 // led on nucleo board
00019 DigitalOut user_led(LED1);      // create DigitalOut object to command user led
00020 
00021 // additional Led
00022 DigitalOut extra_led(PB_9);     // create DigitalOut object to command extra led (do add an aditional resistor, e.g. 220...500 Ohm)
00023 
00024 // mechanical button
00025 DigitalIn mechanical_button(PC_5);  // create DigitalIn object to evaluate extra mechanical button, you need to specify the mode for proper usage, see below
00026 
00027 // Sharp GP2Y0A41SK0F, 4-40 cm IR Sensor
00028 float ir_distance_mV = 0.0f;    // define variable to store measurement
00029 AnalogIn ir_analog_in(PC_2);    // create AnalogIn object to read in infrared distance sensor, 0...3.3V are mapped to 0...1
00030 
00031 // 78:1, 100:1, ... Metal Gearmotor 20Dx44L mm 12V CB
00032 DigitalOut enable_motors(PB_15);    // create DigitalOut object to enable dc motors
00033 
00034 float   pwm_period_s = 0.00005f;    // define pwm period time in seconds and create FastPWM objects to command dc motors
00035 FastPWM pwm_M1(PB_13);              // motor M1 is used open loop
00036 FastPWM pwm_M2(PA_9);               // motor M2 is closed-loop speed controlled (angle velocity)
00037 FastPWM pwm_M3(PA_10);              // motor M3 is closed-loop position controlled (angle controlled)
00038 
00039 EncoderCounter  encoder_M1(PA_6, PC_7); // create encoder objects to read in the encoder counter values
00040 EncoderCounter  encoder_M2(PB_6, PB_7);
00041 EncoderCounter  encoder_M3(PA_0, PA_1);
00042 
00043 // create SpeedController and PositionController objects, default parametrization is for 78.125:1 gear box
00044 float max_voltage = 12.0f;                  // define maximum voltage of battery packs, adjust this to 6.0f V if you only use one batterypack
00045 float counts_per_turn = 20.0f * 78.125f;    // define counts per turn at gearbox end: counts/turn * gearratio
00046 float kn = 180.0f / 12.0f;                  // define motor constant in rpm per V
00047 float k_gear = 100.0f / 78.125f;            // define additional ratio in case you are using a dc motor with a different gear box, e.g. 100:1
00048 float kp = 0.1f;                            // define custom kp, this is the default speed controller gain for gear box 78.125:1
00049 
00050 // SpeedController speedController_M2(counts_per_turn, kn, max_voltage, pwm_M2, encoder_M2); // default 78.125:1 gear box  with default contoller parameters
00051 SpeedController speedController_M2(counts_per_turn * k_gear, kn / k_gear, max_voltage, pwm_M2, encoder_M2); // parameters adjusted to 100:1 gear
00052 
00053 float max_speed_rps = 0.5f;                 // define maximum speed that the position controller is changig the speed, has to be smaller or equal to kn * max_voltage
00054 // PositionController positionController_M3(counts_per_turn, kn, max_voltage, pwm_M3, encoder_M3); // default 78.125:1 gear with default contoller parameters
00055 PositionController positionController_M3(counts_per_turn * k_gear, kn / k_gear, kp * k_gear, max_voltage, pwm_M3, encoder_M3); // parameters adjusted to 100:1 gear, we need a different speed controller gain here
00056 
00057 // Futaba Servo S3001 20mm 3kg Analog
00058 Servo servo_S1(PB_2);           // create servo objects
00059 Servo servo_S2(PC_8);
00060 float servo_S1_angle = 0;       // servo S1 normalized angle
00061 float servo_S2_angle = 0;       // servo S2 normalized angle
00062 int servo_period_mus = 20000;   // define servo period time in mus
00063 
00064 int servo_counter = 0;          // define servo counter, this is an additional variable to make the servos move
00065 int loops_per_seconds = static_cast<int>(ceilf(1.0f/(0.001f*(float)main_task_period_ms))); // define loops per second
00066 
00067 // Groove Ultrasonic Ranger V2.0
00068 float us_distance_cm = 0.0f;    // define variable to store measurement
00069 RangeFinder us_range_finder(PB_12, 5782.0f, 0.02f, 17500); // create range finder object (ultra sonic distance sensor), 20 Hz parametrization
00070 // RangeFinder us_range_finder(PB_12, 5782.0f, 0.02f,  7000); // create range finder object (ultra sonic distance sensor), 50 Hz parametrization
00071 
00072 // LSM9DS1 IMU, carefull: not all PES boards have an imu (chip shortage)
00073 // LSM9DS1 imu(PC_9, PA_8); // create LSM9DS1 comunication object, if you want to be able to use the imu you need to #include "LSM9DS1_i2c.h"
00074 
00075 int main()
00076 {
00077     // attach button fall and rise functions to user button object
00078     user_button.fall(&user_button_pressed_fcn);
00079     user_button.rise(&user_button_released_fcn);
00080 
00081     // start timer
00082     main_task_timer.start();
00083 
00084     // set pullup mode: add resistor between pin and 3.3 V, so that there is a defined potential
00085     mechanical_button.mode(PullUp);
00086 
00087     // enable hardwaredriver dc motors: 0 -> disabled, 1 -> enabled
00088     enable_motors = 1;
00089 
00090     // motor M1 is used open-loop, we need to initialize the pwm and set pwm output to zero at the beginning, range: 0...1 -> u_min...u_max: 0.5 -> 0 V
00091     pwm_M1.period(pwm_period_s);
00092     pwm_M1.write(0.5f);
00093 
00094     // set the soft pwm period for the servo objects
00095     servo_S1.SetPeriod(servo_period_mus);
00096     servo_S2.SetPeriod(servo_period_mus);
00097 
00098     while (true) { // this loop will run forever
00099 
00100         main_task_timer.reset();
00101 
00102         if (do_execute_main_task) {
00103 
00104             // read analog input
00105             ir_distance_mV = 1.0e3f * ir_analog_in.read() * 3.3f;
00106 
00107             // command dc motors if mechanical button is pressed
00108             if (mechanical_button.read()) {
00109                 pwm_M1.write(0.75f); // write output voltage to motor M1
00110                 speedController_M2.setDesiredSpeedRPS(0.5f); // set a desired speed for speed controlled dc motors M2
00111                 positionController_M3.setDesiredRotation(1.5f, max_speed_rps); // set a desired rotation for position controlled dc motors M3
00112             } else {
00113                 pwm_M1.write(0.5f);
00114                 speedController_M2.setDesiredSpeedRPS(0.0f);
00115                 positionController_M3.setDesiredRotation(0.0f, max_speed_rps);
00116             }
00117 
00118             // check if servos are enabled
00119             if (!servo_S1.isEnabled()) servo_S1.Enable();
00120             if (!servo_S2.isEnabled()) servo_S2.Enable();
00121             // command servo position, this needs to be calibrated
00122             servo_S1.SetPosition(servo_S1_angle);
00123             if (servo_S1_angle < 1.0f & servo_counter%loops_per_seconds == 0 & servo_counter != 0) {
00124                 servo_S1_angle += 0.01f;
00125             }
00126             servo_S2.SetPosition(servo_S2_angle);
00127             if (servo_S2_angle < 1.0f & servo_counter%loops_per_seconds == 0 & servo_counter != 0) {
00128                 servo_S2_angle += 0.01f;
00129             }
00130             servo_counter++;
00131 
00132             // read ultra sonic distance sensor
00133             us_distance_cm = us_range_finder.read_cm();
00134 
00135             // visual feedback that the main task is executed
00136             extra_led = 1;
00137 
00138         } else {
00139 
00140             ir_distance_mV = 0.0f;
00141 
00142             pwm_M1.write(0.5f);
00143             speedController_M2.setDesiredSpeedRPS(0.0f);
00144             positionController_M3.setDesiredRotation(0.0f, max_speed_rps);
00145 
00146             servo_S1_angle = 0;
00147             servo_S2_angle = 0;
00148             // servo_S1.SetPosition(servo_S1_angle);
00149             // servo_S2.SetPosition(servo_S2_angle);
00150             if (servo_S1.isEnabled()) servo_S1.Disable();
00151             if (servo_S2.isEnabled()) servo_S2.Disable();
00152 
00153             us_distance_cm = 0.0f;
00154 
00155             extra_led = 0;
00156         }
00157 
00158         user_led = !user_led;
00159 
00160         // do only output via serial what's really necessary (this makes your code slow)
00161         printf("IR sensor (mV): %3.3f, Encoder M1: %3d, Speed M2 (rps) %3.3f, Position M3 (rot): %3.3f, Servo S1 angle (normalized): %3.3f, Servo S2 angle (normalized): %3.3f, US sensor (cm): %3.3f\r\n",
00162                ir_distance_mV,
00163                encoder_M1.read(),
00164                speedController_M2.getSpeedRPS(),
00165                positionController_M3.getRotation(),
00166                servo_S1_angle,
00167                servo_S2_angle,
00168                us_distance_cm);
00169 
00170         // read out the imu, the actual frames of the sensor reading needs to be figured out
00171         // imu.updateGyro();
00172         // imu.updateAcc();
00173         // imu.updateMag();
00174         // printf("%.6f, %.6f, %.6f, %.6f, %.6f, %.6f, %.6f, %.6f, %.6f\r\n", imu.readGyroX(), imu.readGyroY(), imu.readGyroZ(),
00175         // imu.readAccX(), imu.readAccY(), imu.readAccZ(), imu.readMagX(), imu.readMagY(), imu.readMagZ());
00176 
00177         // read timer and make the main thread sleep for the remaining time span (non blocking)
00178         int main_task_elapsed_time_ms = std::chrono::duration_cast<std::chrono::milliseconds>(main_task_timer.elapsed_time()).count();
00179         thread_sleep_for(main_task_period_ms - main_task_elapsed_time_ms);
00180     }
00181 }
00182 
00183 void user_button_pressed_fcn()
00184 {
00185     user_button_timer.start();
00186     user_button_timer.reset();
00187 }
00188 
00189 void user_button_released_fcn()
00190 {
00191     // read timer and toggle do_execute_main_task if the button was pressed longer than the below specified time
00192     int user_button_elapsed_time_ms = std::chrono::duration_cast<std::chrono::milliseconds>(user_button_timer.elapsed_time()).count();
00193     user_button_timer.stop();
00194     if (user_button_elapsed_time_ms > 200) {
00195         do_execute_main_task = !do_execute_main_task;
00196     }
00197 }