Control a Robotic Arm with ESP32

Difficulty Level: Intermediate

This tutorial demonstrates how to control a robotic arm using an ESP32 microcontroller. You will learn how to connect the servos, write the control code, and use a simple web interface to manipulate the arm.

Required Components

• 1 x ESP32 Development Board
• 4 x Servos (SG90 or similar)
• 1 x Robotic Arm Kit
• Jumper wires
• USB cable to connect ESP32 to your computer
• Optional: Power supply for servos (if needed)

Wiring the Robotic Arm

Connect the servos to the ESP32 as follows:

• Servo 1: Signal pin to GPIO 23
• Servo 2: Signal pin to GPIO 22
• Servo 3: Signal pin to GPIO 21
• Servo 4: Signal pin to GPIO 19
• Connect all servo ground wires to GND and power wires to 5V (or external power if necessary).

Code Explanation

The following code allows you to control the robotic arm via a simple web interface hosted on the ESP32. It uses the Servo library to handle the servo positions.

Key Functions

• Servo.attach(): Attaches the servo to a pin.
• Servo.write(): Sets the angle of the servo motor.
• WiFi.begin(): Connects the ESP32 to your Wi-Fi network.
• server.on(): Defines the web server routes for control.

Arduino Code

Here’s the Arduino code for controlling the robotic arm:

#include 
#include 
#include 

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

WebServer server(80);
Servo servo1, servo2, servo3, servo4;

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  // Attach servos
  servo1.attach(23);
  servo2.attach(22);
  servo3.attach(21);
  servo4.attach(19);

  // Define routes
  server.on("/", handleRoot);
  server.on("/move", handleMove);
  server.begin();
}

void loop() {
  server.handleClient();
}

void handleRoot() {
  String html = "
Control Robotic Arm
"
                "
"
                "Servo 1 Angle: 
"
                "Servo 2 Angle: 
"
                "Servo 3 Angle: 
"
                "Servo 4 Angle: 
"
                ""
                "
";
  server.send(200, "text/html", html);
}

void handleMove() {
  int servo1Angle = server.arg("servo1").toInt();
  int servo2Angle = server.arg("servo2").toInt();
  int servo3Angle = server.arg("servo3").toInt();
  int servo4Angle = server.arg("servo4").toInt();

  servo1.write(servo1Angle);
  servo2.write(servo2Angle);
  servo3.write(servo3Angle);
  servo4.write(servo4Angle);

  server.send(200, "text/html", "Moved! Go back");
}
            

Upload and Test

1. Connect your ESP32 to your computer using the USB cable.
2. Open the Arduino IDE and copy the code above into the editor.
3. Replace YOUR_SSID and YOUR_PASSWORD with your Wi-Fi credentials.
4. Select your ESP32 board and the correct port in the IDE.
5. Click the upload button to send the code to the ESP32.
6. Open the Serial Monitor to find the IP address of the ESP32.
7. Enter the IP address into a web browser to access the control interface.

Conclusion

In this tutorial, you learned how to control a robotic arm using an ESP32 and servos. The web interface allows you to adjust the angles of the servos and control the arm remotely. This project can be expanded by adding more features such as automated movements or feedback systems.