ESP8266 WIFI D1 R2 Dev. Board, 32M Flash RobotDYN

The board integrates an ESP8266 microcontroller with onboard flash memory, a CH340C USB-to-serial converter, and both a built-in PCB antenna and an external antenna connector. Programming is performed using the Arduino IDE, just like traditional Arduino boards.

Features

• ESP8266 Wi-Fi microcontroller.
• Arduino UNO-compatible layout.
• Built-in Wi-Fi antenna.
• External antenna connector.
• CH340C USB-to-serial interface.
• Supports Arduino IDE programming.
• OTA (Over-The-Air) firmware updates.
• Compact and lightweight design.

Specifications

• Microcontroller: ESP8266
• USB-TTL Converter: CH340C
• Clock Frequency: Up to 160 MHz
• Operating Voltage: 3.3V
• Flash Memory: 32Mb (4MB)
• Wi-Fi: 802.11 b/g/n (2.4 GHz)
• Logic Level: 3.3V (5V tolerant inputs on some pins)
• Digital I/O: 11
• Analogue Input: 1 (A0)
• Power Input (USB): 5V
• Power Input (VIN / DC Jack): 9–24V
• Power Output: 3.3V / 5V
• Interface: Serial / OTA
• Dimensions: 53.34 × 68.51 mm
• Weight: 8 g
• Operating Temperature: −40°C to +125°C
• Antenna: Built-in / External

USB Driver Requirement

The board uses a CH340 USB converter. Install the CH340 driver if your computer does not detect the board.

Programming Environment

Compatible with the Arduino IDE. Install ESP8266 board support via:

• Arduino IDE → Preferences → Additional Boards Manager URLs
• Add ESP8266 board package URL: http://arduino.esp8266.com/stable/package_esp8266com_index.json 
• Tools → Board → Boards Manager → ESP8266

Required Libraries

OTA updates require the ArduinoOTA library (included with ESP8266 package).

#include <ESP8266WiFi.h>
#include <WiFiUdp.h>
#include <ArduinoOTA.h>

Basic Blink Example

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

void loop() {
  digitalWrite(LED_BUILTIN, LOW);
  delay(500);
  digitalWrite(LED_BUILTIN, HIGH);
  delay(500);
}

Hardware Example

Connect components as shown in the schematic to test a basic LED blink project.

OTA Update Preparation

OTA (Over-The-Air) updates allow wireless firmware uploads without USB cables. Modern Arduino IDE versions already include required tools — Python manual installation is typically unnecessary.

Basic OTA Example

#include <ESP8266WiFi.h>
#include <WiFiUdp.h>
#include <ArduinoOTA.h>

const char* ssid = "YOUR_SSID";
const char* password = "YOUR_PASSWORD";

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
  
  Serial.begin(115200);

  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

  while (WiFi.waitForConnectResult() != WL_CONNECTED) {
    delay(5000);
    ESP.restart();
  }

  ArduinoOTA.begin();
}

void loop() {
  ArduinoOTA.handle();

  digitalWrite(LED_BUILTIN, LOW);
  delay(500);
  digitalWrite(LED_BUILTIN, HIGH);
  delay(500);
}

How OTA Works

• Upload OTA-enabled sketch via USB once.
• Board connects to Wi-Fi network.
• New network port appears in Arduino IDE.
• Future uploads can be done wirelessly.

Important OTA Note

OTA functionality must be included in every sketch you upload via OTA. Otherwise, the wireless update capability will be lost.

Applications

• IoT devices
• Wireless sensors
• Smart home systems
• Remote monitoring
• Network-connected controllers

Tips & Information

• ESP8266 operates at 3.3V logic level.
• Avoid applying 5V directly to GPIO pins.
• Use level shifters for 5V peripherals if needed.
• External antenna improves Wi-Fi range.
• VIN input supports wide voltage range.
• OTA is ideal for hard-to-reach installations.