Remote Control

ICT 361: Introduction to Robotics

Mr. Seng Theara

Learning Objective

By the end of the lesson, student will be able to:

Understand how a joystick works electrically
Explain pull-up button logic
Read analog and digital signals
Map controller inputs to robot movements
Design basic control logic for robots

Learning Objective

By the end of the lesson, student will be able to:

Understand how a joystick works electrically
Explain pull-up button logic
Read analog and digital signals
Map controller inputs to robot movements
Design basic control logic for robots

Remote

4 Buttons

Joystick

Remote

4 Push Buttons

Joystick

Function of Push Button

From this connection, we see that when the button is not pressed, the esp32 pin is connect to Vcc(3.3V). So, it means that it is HIGH
But when the Button is pressed, the esp32 pin flow into the GND. So, it means that it is LOW

Function of Push Button

From this connection, we see that when the button is not pressed, the esp32 pin is connect to Vcc(3.3V). So, it means that it is HIGH
But when the Button is pressed, the esp32 pin flow into the GND. So, it means that it is LOW

Pins of Push Button

Pin 16

Pin 4

Pin 15

Pin 2

void setup() {
  pinMode(16, INPUT);
  Serial.begin(115200);
}

void loop() {
  int button_up = digitalRead(16);
  if (button_up == LOW){
    Serial.println("Button Up is pressed");
  }else{
    Serial.println("Button Up isn't pressed");
  }

  delay(200);
}

Pins of Push Button

Pin 16

Pin 4

Pin 15

Pin 2

void setup() {
  pinMode(16, INPUT);
  Serial.begin(115200);
}

void loop() {
  int button_up = digitalRead(16);
  if (button_up == LOW){
    Serial.println("Button Up is pressed");
  }else{
    Serial.println("Button Up isn't pressed");
  }

  delay(200);
}

Declare pin 16 as INPUT because the esp32 read from the button

Pins of Push Button

Pin 16

Pin 4

Pin 15

Pin 2

void setup() {
  pinMode(16, INPUT);
  Serial.begin(115200);
}

void loop() {
  int button_up = digitalRead(16);
  if (button_up == LOW){
    Serial.println("Button Up is pressed");
  }else{
    Serial.println("Button Up isn't pressed");
  }

  delay(200);
}

Declare pin 16 as INPUT because the esp32 read from the button

Using baudrate of 115200

Pins of Push Button

Pin 16

Pin 4

Pin 15

Pin 2

void setup() {
  pinMode(16, INPUT);
  Serial.begin(115200);
}

void loop() {
  int button_up = digitalRead(16);
  if (button_up == LOW){
    Serial.println("Button Up is pressed");
  }else{
    Serial.println("Button Up isn't pressed");
  }

  delay(200);
}

Declare pin 16 as INPUT because the esp32 read from the button

Using baudrate of 115200

We declare a button_up variable to read the state of the button to check whether it is pressed or not pressed

Pins of Push Button

Pin 16

Pin 4

Pin 15

Pin 2

void setup() {
  pinMode(16, INPUT);
  Serial.begin(115200);
}

void loop() {
  int button_up = digitalRead(16);
  if (button_up == LOW){
    Serial.println("Button Up is pressed");
  }else{
    Serial.println("Button Up isn't pressed");
  }

  delay(200);
}

Declare pin 16 as INPUT because the esp32 read from the button

Using baudrate of 115200

We declare a button_up variable to read the state of the button to check whether it is pressed or not pressed

Finally, we have a condition to verify if the button_up is LOW, we print the button up is press. If not, print the button up isn't pressed

Code of Push Button

Pin 16

Pin 4

Pin 15

Pin 2

void setup() {
  pinMode(16, INPUT);
  Serial.begin(115200);
}

void loop() {
  int button_up = digitalRead(16);
  if (button_up == LOW){
    Serial.println("Button Up is pressed");
  }else{
    Serial.println("Button Up isn't pressed");
  }

  delay(200);
}

Declare pin 16 as INPUT because the esp32 read from the button

Using baudrate of 115200

We declare a button_up variable to read the state of the button to check whether it is pressed or not pressed

Finally, we have a condition to verify if the button_up is LOW, we print the button up is pressed. If not, print the button up isn't pressed

Function of Joystick

A joystick is an input device that allows a user to control movement or direction by pushing a stick in different directions. It is widely used in robotics, gaming controllers, drones, and control panels.

Movement	Axis	Typical Use
Left / Right	X-axis	Turning, steering
Up / Down	Y-axis	Forward / backward
Center	Neutral	Stop / idle

Function of Joystick

4095

2048

The ESP32 uses a 12-bit ADC (Analog-to-Digital Converter).

12-bit ADC represent:

2^{12} = 4096 \quad \text{These levels are numbered from }\quad 0 \rightarrow 4095

Function of Joystick


const int joyX = 34;
const int joyY = 35;

int xValue = 0;
int yValue = 0;

void setup() {
  Serial.begin(115200);

  // ADC pins do not need pinMode
  Serial.println("ESP32 Joystick Reading Started");
}

void loop() {
  xValue = analogRead(joyX);  // 0 - 4095
  yValue = analogRead(joyY);  // 0 - 4095

  Serial.print("X: ");
  Serial.print(xValue);
  Serial.print(" | Y: ");
  Serial.println(yValue);

  delay(200);
}