Visualize TCRT5000 IR Sensor on OLED with a Real-Time Bar Graph

This simple yet powerful project uses a TCRT5000 IR Reflective Sensor and an SSD1306 OLED display to visualize distance or surface reflectivity as a horizontal bar graph in real time.

As objects move closer to the sensor, the bar grows longer — giving you instant feedback. This is great for proximity sensing, object tracking, or even basic gesture interfaces.

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Hardware Components

You’ll need the following hardware components to get started:

Component	Model / Type	Qty
Arduino UNO	R3 Board	1
TCRT5000 IR Sensor	Reflective IR Module	1
OLED Display	SSD1306 128×64 I2C (0.96″)	1
Jumper Wires	Male-to-male	1 set
Breadboard	Optional	1
USB Cable	For Arduino	1

Schematic

Make connections according to the circuit diagram given below.

Wiring / Connections

Component	Arduino UNO	Notes
OLED VCC	5V or 3.3V	Power for display
OLED GND	GND	Ground
OLED SDA	A4	I2C Data
OLED SCL	A5	I2C Clock
TCRT5000 VCC	5V	Power for sensor
TCRT5000 GND	GND	Ground
TCRT5000 A0 / OUT	A0	Analog sensor output

Arduino Code

#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

const int sensorPin = A0; // IR sensor analog output pin

void setup() {
  Serial.begin(9600);
  pinMode(sensorPin, INPUT);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("OLED init failed"));
    for (;;);
  }
  display.clearDisplay();
  display.setTextColor(SSD1306_WHITE);
}

void loop() {
  int sensorValue = analogRead(sensorPin);
  int barLength = map(sensorValue, 640, 30, 0, 120); // Closer = longer bar
  barLength = constrain(barLength, 0, 120);

  display.clearDisplay();

  // Draw bar graph
  display.fillRect(4, 30, barLength, 10, SSD1306_WHITE);
  
  // Display numeric value
  display.setCursor(4, 10);
  display.setTextSize(1);
  display.print("IR Value: ");
  display.println(sensorValue);

  // Optional scale lines
  for (int i = 0; i <= 120; i += 20) {
    display.drawLine(4 + i, 28, 4 + i, 42, SSD1306_WHITE);
  }

  display.display();
  delay(100);
}

This program reads analog values from the TCRT5000 IR sensor and converts them into a visual bar graph on the SSD1306 OLED screen.

Key Features:

• Live bar graph that grows as objects get closer
• Text display showing the exact IR value
• Optional scale markers every 20 pixels

Code Walkthrough

int sensorValue = analogRead(sensorPin);

• Reads analog output from the IR sensor.

int barLength = map(sensorValue, 640, 30, 0, 120);

• Maps sensor values (from dark to reflective surfaces) into a bar range (0 to 120 px). Higher reflectivity (closer object) gives a longer bar.

barLength = constrain(barLength, 0, 120);

• Ensures the bar doesn’t go out of bounds.

display.fillRect(4, 30, barLength, 10, SSD1306_WHITE);

• Draws the bar horizontally on screen.

display.setCursor(4, 10);
display.print("IR Value: ");

• Prints the numeric sensor value above the bar.

for (int i = 0; i <= 120; i += 20) {
  display.drawLine(4 + i, 28, 4 + i, 42, SSD1306_WHITE);
}

Draws vertical ticks every 20 pixels to serve as visual reference markers.

Conclusion

This project is perfect for learning about analog sensor input and real-time data visualization. It’s minimal in components but rich in insight!