Arduino UNO R4 - Potentiometer fade LED
This tutorial instructs you how to program the Arduino UNO R4 to control the brightness of an LED based on the output value of a potentiometer.
Hardware Preparation
Or you can buy the following sensor kits:
| 1 | × | DIYables Sensor Kit (30 sensors/displays) | |
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
Disclosure: Some of the links provided in this section are Amazon affiliate links. We may receive a commission for any purchases made through these links at no additional cost to you.
Additionally, some of these links are for products from our own brand, DIYables.
Additionally, some of these links are for products from our own brand, DIYables.
Overview of LED and Potentiometer
Learn about LED and potentiometer (pinout, functionality, programming) in the tutorials provided:
Wiring Diagram
This image is created using Fritzing. Click to enlarge image
See The best way to supply power to the Arduino Uno R4 and other components.
How To Program
- Reads the input on the analog pin A0 (value ranges from 0 to 1023)
int adc_value = analogRead(A0);
- Convert it to a brightness level (a number from 0 to 255)
int brightness = map(adc_value, 0, 1023, 0, 255);
- Sets the brightness of the LED connected to pin 3.
analogWrite(LED_PIN, brightness);
Arduino UNO R4 Code
/*
* This Arduino UNO R4 code was developed by newbiely.com
*
* This Arduino UNO R4 code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-uno-r4/arduino-uno-r4-potentiometer-fade-led
*/
#define LED_PIN 3 // The Arduino UNO R4 pin connected LED
#define POTENTIOMETER_PIN A0 // The Arduino UNO R4 pin connected potentiometer
void setup() {
// initialize serial communication at 9600 bits per second:
Serial.begin(9600);
// declare LED pin to be an output:
pinMode(LED_PIN, OUTPUT);
}
void loop() {
// reads the input on analog pin A0 (value between 0 and 1023)
int adc_value = analogRead(POTENTIOMETER_PIN);
// scales it to brightness (value between 0 and 255)
int brightness = map(adc_value, 0, 1023, 0, 255);
// sets the brightness LED that connects to pin 3
analogWrite(LED_PIN, brightness);
// print out the value
Serial.print("Analog: ");
Serial.print(adc_value);
Serial.print(", Brightness: ");
Serial.println(brightness);
delay(100);
}
Detailed Instructions
Follow these instructions step by step:
- If this is your first time using the Arduino Uno R4 WiFi/Minima, refer to the tutorial on setting up the environment for Arduino Uno R4 WiFi/Minima in the Arduino IDE.
- Wire the components according to the provided diagram.
- Connect the Arduino Uno R4 board to your computer using a USB cable.
- Launch the Arduino IDE on your computer.
- Select the appropriate Arduino Uno R4 board (e.g., Arduino Uno R4 WiFi) and COM port.
- Copy the code and open it in Arduino IDE
- Click the Upload button in Arduino IDE to upload the code to Arduino UNO R4
- Open the Serial Monitor
- Turn the potentiometer
- Observe the LED
- Check the result on the Serial Monitor
COM6
Analog: 6, Brightness: 1
Analog: 34, Brightness: 8
Analog: 89, Brightness: 22
Analog: 149, Brightness: 37
Analog: 214, Brightness: 53
Analog: 297, Brightness: 74
Analog: 365, Brightness: 90
Analog: 431, Brightness: 107
Analog: 510, Brightness: 127
Analog: 589, Brightness: 146
Analog: 695, Brightness: 173
Analog: 790, Brightness: 196
Analog: 970, Brightness: 241
Analog: 996, Brightness: 248
Analog: 1018, Brightness: 253
Analog: 1023, Brightness: 255
Autoscroll
Clear output
9600 baud
Newline