Basic to control a motor through Blynk (app or web)

steppermotor_blynk_firmware.ino

// Template ID, Device Name and Auth Token are provided by the Blynk.Cloud
// See the Device Info tab, or Template settings
#define BLYNK_TEMPLATE_ID           ""
#define BLYNK_DEVICE_NAME           "WemosD1 Motor Control"
#define BLYNK_AUTH_TOKEN            ""


// Comment this out to disable prints and save space
#define BLYNK_PRINT Serial

// A4988 driver pins
const int motMS1Pin = D0;
const int motMS2Pin = D5;
const int motMS3Pin = D6;
const int motStepPin = D7;
const int motDirPin = D8;

int motorDirection = 1;
int motorSpeed = 10;
int stepDelay = 2000;       // delay in microseconds
bool motorStatus = true;
bool isCalibrated = false;

#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>

char auth[] = BLYNK_AUTH_TOKEN;

// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "";
char pass[] = "";

BlynkTimer timer;

// V0 is the On/Off button for controlling the stepper motor (0 is off, 1 is on)
BLYNK_WRITE(V0)
{
  int v0 = param.asInt(); 
//  Serial.print("V0 is the On/Off Button value: ");
//  Serial.println(v0);
  motorStatus = v0;
}

// V1 is the direction for the stepper motor (0 is left, 1 is right)
BLYNK_WRITE(V1) {
  int v1 = param.asInt();
//  Serial.print("V1 is the direction value: ");
//  Serial.println(v1);
  motorDirection = v1;
}


// V4 is the motor speed (value between 0 and 100)
BLYNK_WRITE(V4) {
  int v4 = param.asInt();
  Serial.print("V4 is the speed value (slider): ");
  Serial.println(v4);
  stepDelay = map(v4, 0, 100, 5000, 700);
}


// This function is called every time the device is connected to the Blynk.Cloud
BLYNK_CONNECTED()
{
  // Change Web Link Button message to "Congratulations!"
//   Blynk.setProperty(V3, "offImageUrl", "");
//   Blynk.setProperty(V3, "onImageUrl",  "");
//   Blynk.setProperty(V3, "url", "");
}

// This function sends Arduino's uptime every second to Virtual Pin 2.
void myTimerEvent()
{
  // You can send any value at any time.
  // Please don't send more that 10 values per second.
   Blynk.virtualWrite(V2, millis() / 1000);
}

void setup()
{
  // Debug console
  Serial.begin(9600);

  Blynk.begin(auth, ssid, pass);
  // You can also specify server:
  //Blynk.begin(auth, ssid, pass, "blynk.cloud", 80);
  //Blynk.begin(auth, ssid, pass, IPAddress(192,168,1,100), 8080);

  // Setup a function to be called every second
  timer.setInterval(1000L, myTimerEvent);

  pinMode(motMS1Pin, OUTPUT);
  pinMode(motMS2Pin, OUTPUT);
  pinMode(motMS3Pin, OUTPUT);  
  pinMode(motStepPin, OUTPUT);
  pinMode(motDirPin, OUTPUT);

  digitalWrite(motMS1Pin, HIGH);
  digitalWrite(motMS2Pin, HIGH);
  digitalWrite(motMS3Pin, HIGH);

}

void loop()
{
  Blynk.run();
  timer.run();
  // You can inject your own code or combine it with other sketches.
  // Check other examples on how to communicate with Blynk. Remember
  // to avoid delay() function!

  digitalWrite(motDirPin, motorDirection);
  if (motorStatus) {
    digitalWrite(motStepPin, HIGH);
    delayMicroseconds(stepDelay);
    digitalWrite(motStepPin, LOW);
    delayMicroseconds(stepDelay);
  }

}