File content as of revision 0:d91567547359:

// Nucleo_CAN_slave (AIRo-4.1)
// Angle control
// Created by Atsushi Kakogawa, 2019.09.19
// Edited by Yoshimichi Oka, 2020.2.5
// Modified by Atsushi Kakogawa, 2020.03.22
// Department of Robotics, Ritsumeikan University, Japan
#include "mbed.h"
#include "CAN.h"

Ticker control; // timer for control
DigitalOut myled(PF_1);     // LED for communication check
DigitalOut mdir1(PA_9);     // D1 Motor ON/OFF (HIGH = ON, Changeable on ESCON Studio)
DigitalOut mdir2(PA_10);    // D0 Rotational direction (Direction is changeable on ESCON Studio)
AnalogOut DA_vlc(PA_6);     // A5 for velocity analog input to ESCON ANI1+ (0 to 1.0)
AnalogOut DA_crt(PA_5);     // A3 for current anaglog input to ESCON ANI2+ (0 to 1.0)
AnalogIn potensio1(PA_0); 
//AnalogIn potensio2(PA_7); // A6 Potentiometer 2 (5V potentiometer)
AnalogIn AD_crt(PA_1);      // Analog Signal from ESCON ANO1 (motor velocity, can be changed by ESCON) (0 to 1.0)
AnalogIn AD_vlc(PA_3);      // Analog Signal from ESCON AO2 (motor current,  can be changed by ESCON) (0 to 1.0)

float duty = 0;
int id = 7;
int flag = 0;
float target_ang1 = 0.6, ang, e = 0, pang, de = 0;
float kp=0.01, kd = 0.1;

char tx_data[8];
char tx_data1_U, tx_data1_L, tx_data2_U, tx_data2_L, tx_data3_U, tx_data3_L;

// PD-control timer
void controller() {
    ang = (1-potensio1.read())*30;
    e = target_ang1 - ang;
    de = ang - pang;
    DA_crt = kp*abs(e) - kd*abs(de);
    if (e > 0) {
        mdir1 = 1;
        mdir2 = 0;
    } else if (e < 0) {
        mdir1 = 1;
        mdir2 = 1;
    } else {
        mdir1 = 0;
        mdir2 = 0;
    } 
    pang = ang;
}

int main() {
    
    control.attach(&controller, 0.001);  // 1 ms

    CAN can(PA_11, PA_12);
    can.frequency(100000);
    CANMessage msg;
   
    while(1) {
        if(can.read(msg)) {
            if (msg.data[0] == id) {                                    // ID indentify
                if (msg.data[1] == 0) {                                 // mode indentify (0: control)
                    target_ang1 = (msg.data[3] << 8) + msg.data[4];
                } else if (msg.data[1] == 1) {                          // mode indentify (1: response)
                    int i_data1 = AD_crt.read()*1000; 
                        tx_data1_U = (i_data1 >> 8) & 0xff;
                        tx_data1_L = i_data1 & 0xff;
                    int i_data2 = AD_vlc.read()*1000; 
                        tx_data2_U = (i_data2 >> 8) & 0xff;
                        tx_data2_L = i_data2 & 0xff;
                    int i_data3 = potensio1.read()*330*100; 
                        tx_data3_U = (i_data3 >> 8) & 0xff;
                        tx_data3_L = i_data3 & 0xff;
                    tx_data[0] = id;                                    // ID
                    tx_data[1] = 1;                                     // mode (1: response)
                    tx_data[2] = tx_data1_U;                            // response value1 upper 8bit
                    tx_data[3] = tx_data1_L;                            // response value1 lower 8bit
                    tx_data[4] = tx_data2_U;                            // response value2 upper 8bit
                    tx_data[5] = tx_data2_L;                            // response value2 lower 8bit
                    tx_data[6] = tx_data3_U;                            // response value3 upper 8bit
                    tx_data[7] = tx_data3_L;                            // response value3 lower 8bit
                    can.write(CANMessage(1330, tx_data, 8));
                }
            }
            myled = 1; // LED is ON
            wait (0.01);
        } else {
            myled = 0; // LED is OFF
        }
    } // while 
}