Arduino, Motor/ Robot

Controlling SmartDrive40 Using 3.3V Microcontroller (Serial Simplified Mode)

by Idris
April 24, 2019

Arduino, DC motor, ESP32, Motor Driver, Serial Simplified

If you would like to control Cytron smart motor driver using 3.3V microcontroller, you can try this tutorial.

INTRODUCTION

SmartDrive40 is a smart motor driver series with current capacity up to 80A peak and 40A continuously. It is equipped with a microcontroller unit to provide smart features such as multiple input modes, current limiting and thermal protection. In order to control SmartDrive40 using 3.3V microcontroller, you can consider to use either:

RC MCU mode
Serial Simplified mode
Serial Packetized mode

In this tutorial, I will show you how to control SmartDrive40 using ESP32 board in Serial Simplified mode.

VIDEO

This video shows how to control SmartDrive40 using NodeMCU ESP32 in Serial Simplified mode.

HARDWARE PREPARATION

Below is the list of items used in the video

40Amp 10V-45V SmartDrive DC Motor Driver

NODEMCU ESP32

Breakout Board Rotary Switch

DC Brushed Motor

40 Ways Male to Male Jumper Wire

Breadboard

Wiring connection table.

NodeMCU ESP32	SmartDrive40	Rotary Encoder
VIN	5V
GND	GND	GND
D13	IN1
D14	IN2
3.3V		VCC
D25		CE
D26		EA
D27		EB

Sample Code

This is the sample code used in the video. Please install ESP32 board in your Arduino IDE first.

      
        #define RXD_DUMMY   12
      
        #define MDS40B_IN1  13
      
        #define MDS40B_IN2  14
      
        #define MDS40BSerial  Serial1
      
        #define BBRS_CE 25
      
        #define BBRS_EA 26
      
        #define BBRS_EB 27
      
        int motorSpeed = 127;
      
        boolean motorDirection = false;
      
        volatile int lastEncoded = 0;
      
        volatile long encoderValue = 0;
      
        long lastencoderValue = 0;
      
        int lastMSB = 0;
      
        int lastLSB = 0;
      
        boolean printEncoder = false;
      
        void updateEncoder()
      
        {
      
          int MSB = digitalRead(BBRS_EA); //MSB = most significant bit
      
          int LSB = digitalRead(BBRS_EB); //LSB = least significant bit
      
          int encoded = (MSB << 1) | LSB; //converting the 2 pin value to single number
      
          int sum = (lastEncoded << 2) | encoded; //adding it to the previous encoded value
      
          if (sum == 0b1101 || sum == 0b0100 || sum == 0b0010 || sum == 0b1011) {
      
            encoderValue ++;
      
          }
      
          if (sum == 0b1110 || sum == 0b0111 || sum == 0b0001 || sum == 0b1000) {
      
            encoderValue --;
      
          }
      
          lastEncoded = encoded; //store this value for next time
      
          encoderValue = constrain(encoderValue, 0, 100);
      
          printEncoder = true;
      
        }
      
        void setup()
      
        {
      
          pinMode(BBRS_CE, INPUT);
      
          pinMode(BBRS_EA, INPUT);
      
          pinMode(BBRS_EB, INPUT);
      
          pinMode(MDS40B_IN2, OUTPUT);
      
          digitalWrite(MDS40B_IN2, HIGH);
      
          Serial.begin(115200);
      
          MDS40BSerial.begin(9600, SERIAL_8N1, RXD_DUMMY, MDS40B_IN1);
      
          MDS40BSerial.write(motorSpeed);
      
          delay(1000);
      
          attachInterrupt(digitalPinToInterrupt(BBRS_EA), updateEncoder, CHANGE);
      
          attachInterrupt(digitalPinToInterrupt(BBRS_EB), updateEncoder, CHANGE);
      
          Serial.println();
      
          Serial.println();
      
          Serial.println("Controlling SmartDrive-40 Using ESP32 Controller");
      
          Serial.println();
      
          Serial.print("Enc:\tSpeed:");
      
        }
      
        void loop()
      
        {
      
          if (printEncoder == true) {
      
            printEncoder = false;
      
            if (motorDirection == false) {
      
              motorSpeed = map(encoderValue, 0, 100, 127, 255);
      
            }
      
            else if (motorDirection == true) {
      
              motorSpeed = map(encoderValue, 0, 100, 127, 0);
      
            }
      
            Serial.print(encoderValue);
      
            Serial.print("\t");
      
            Serial.println(motorSpeed);
      
            MDS40BSerial.write(motorSpeed);
      
          }
      
          if (digitalRead(BBRS_CE) == LOW) {
      
            motorDirection = !motorDirection;
      
            encoderValue = 0;
      
            motorSpeed = 127;
      
            MDS40BSerial.write(motorSpeed);
      
            Serial.println();
      
            Serial.println("Change Direction!");
      
            Serial.println();
      
            Serial.print("Enc:\tSpeed:");
      
            while (digitalRead(BBRS_CE) == LOW);
      
            delay(100);
      
          }
      
        }