ESP8266 / ESP32

1. Definition

ESP8266 and ESP32 are Wi-Fi-enabled microcontrollers commonly used in IoT (Internet of Things) projects.

  • The ESP8266 is low-cost and good for simple Wi-Fi projects.
  • The ESP32 is more powerful, with built-in Wi-Fi + Bluetooth, dual-core processing, more GPIOs, and support for advanced projects.

They are great for connecting devices to the internet and building smart systems.

ESP8266 and ESP32 boards

2. Key Features

3.1 ESP8266

  • Wi-Fi support (2.4 GHz)
  • Lower cost and lower power
  • Limited GPIO pins (~11 usable)
  • Single-core processor

3.2. ESP32

  • Wi-Fi + Bluetooth (Classic + BLE)
  • Dual-core processor (faster & more powerful)
  • More GPIOs (~30 usable)
  • Built-in ADC, DAC, capacitive touch, PWM, SPI, I2C, UART
  • Supports deep sleep (low power IoT devices)

3.3. ESP8266 vs ESP32 Comparison

Feature ESP8266 ESP32
Release Year 2014 2016
Processor Single-core Tensilica L106 (80–160 MHz) Dual-core Tensilica Xtensa LX6 (160–240 MHz)
RAM ~160 KB ~520 KB (with external PSRAM options)
Flash Memory Typically 4 MB 4–16 MB (varies by module)
Wi-Fi 2.4 GHz only 2.4 GHz + better speed & stability
Bluetooth Not supported Bluetooth 4.2 & BLE support
GPIO Pins ~17 usable pins 30+ pins (depending on board)
Analog Inputs 1 (10-bit ADC) Up to 18 (12-bit ADC)
PWM Support Yes Yes (more channels & higher resolution)
Communication UART, SPI, I²C UART, SPI, I²C, CAN, I²S
Power Consumption Low Ultra-low power modes available
Cost Cheaper (~$2–4) Slightly more expensive (~$5–8)
Best For Simple IoT projects, Wi-Fi apps Advanced IoT, Bluetooth + Wi-Fi projects

Summary

  • Use ESP8266 if you want a cheap, simple Wi-Fi board for small IoT projects.
  • Use ESP32 if you need more power, more pins, Bluetooth, or multiple sensors.

3. Applications

  • Smart home automation (lights, fans, appliances)
  • IoT projects (weather station, soil monitoring, etc.)
  • Remote sensors with Wi-Fi or Bluetooth data transfer
  • Robotics (Wi-Fi controlled robots)
  • Wearables and portable devices

4. Pinout Examples

ESP8266 (NodeMCU)

  • D0–D8 → Digital pins
  • A0 → Analog input
  • 3.3V / GND → Power supply
  • TX/RX → Serial communication

ESP32 (DevKit)

  • GPIOs → Multiple digital pins
  • ADC/DAC → For analog input/output
  • TX0/RX0, TX1/RX1 → UART communication
  • EN → Reset pin
  • 3.3V / GND → Power supply

5. Example Code 

int led = 2; // On-board LED (D4 on ESP8266, GPIO2 on ESP32)

void setup() {
  pinMode(led, OUTPUT);
}

void loop() {
  digitalWrite(led, HIGH); // LED ON
  delay(1000);
  digitalWrite(led, LOW);  // LED OFF
  delay(1000);
}

6. Video Explanation

Video coming soon