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User’s Guide

NodeMCU ESP‑12E + Motor Shield Expansion Kit

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1. Product Overview

This kit combines the NodeMCU ESP‑12E (ESP8266 Wi‑Fi microcontroller) with a motor shield expansion board. Together, they allow you to control DC motors or a stepper motor directly from the ESP‑12E, while also enabling IoT features like Wi‑Fi remote control.

• Microcontroller: ESP8266 (NodeMCU ESP‑12E)
• Motor Driver IC: L293D (dual H‑bridge)
• Motors Supported: 2 DC motors or 1 stepper motor
• Control Method: GPIO pins + PWM signals from ESP8266
• Expansion Features: Screw terminals, pin headers, buzzer, Bluetooth/relay shield compatibility

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2. Pinout & Connections

Motor Shield Terminals

Terminal	Function
MA+, MA-	Motor A outputs
MB+, MB-	Motor B outputs
VIN	External motor supply (7–12V recommended)
GND	Ground
ENA	Enable/PWM for Motor A
ENB	Enable/PWM for Motor B
IN1, IN2	Motor A direction control
IN3, IN4	Motor B direction control

NodeMCU ESP‑12E Pins (common mapping)

Pin	Function
D1–D4	Motor control inputs (mapped to IN1–IN4)
D5/D6	PWM enable pins (ENA/ENB)
3V3	Logic supply
GND	Ground
VIN	External supply (USB or 7–12V via shield)

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3. Control Logic

Each motor channel works as an H‑bridge:

IN1	IN2	Motor A Action
HIGH	LOW	Forward
LOW	HIGH	Reverse
LOW	LOW	Stop (coast)
HIGH	HIGH	Brake

• Same logic applies for Motor B using IN3/IN4.
• Apply PWM to ENA/ENB pins for speed control.

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4. Wiring Guide

1. Plug the motor shield onto the NodeMCU ESP‑12E.
2. Connect Motor A wires → MA+ / MA-.
3. Connect Motor B wires → MB+ / MB-.
4. Supply external motor voltage → VIN + GND terminals.
5. Power NodeMCU via USB (for programming) or external VIN.

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5. Example Arduino Code (ESP8266)

int IN1 = D1;
int IN2 = D2;
int ENA = D5;

void setup() {
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(ENA, OUTPUT);
}

void loop() {
  // Forward at half speed
  digitalWrite(IN1, HIGH);
  digitalWrite(IN2, LOW);
  analogWrite(ENA, 512); // 50% duty cycle
  delay(2000);

  // Reverse at full speed
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, HIGH);
  analogWrite(ENA, 1023); // 100% duty cycle
  delay(2000);

  // Stop
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, LOW);
  analogWrite(ENA, 0);
  delay(2000);
}

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6. Applications

• Wi‑Fi controlled robots: Drive two DC motors for wheels.
• IoT automation: Control fans, pumps, or actuators via Wi‑Fi.
• Educational kits: Demonstrate PWM speed control and H‑bridge logic.
• Stepper motor projects: Drive bipolar stepper motors with IN1–IN4 sequencing.

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7. Best Practices

• Use external motor supply (7–12V) for reliable operation.
• Do not exceed 600mA per channel (L293D limit).
• Always connect grounds together (ESP8266 + motor supply).
• Add flyback diodes or capacitors if motors cause noise.
• Use PWM for smooth speed control.

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