Dynamic Directional & Information Display System

The “Servo Direction Indicator & Message Scroller” has a novel design that integrates mechanical action and digital messaging using a microcontroller-based system. The project combines a servo motor that provides rotation for indicating direction with an OLED display that scrolls a predetermined message across the screen. The project combines these elements and offers a multidimensional approach to interaction, mixing the feedback of a movement of the servo with the visual way of displaying an information on the OLED.

It can serve as a working model for more complex projects where being able to point out directions or positions is unexpected. Like the example linked below, it is able to do things such as movement direction of a robotic arm which is shown with servo or a process with its status represented on the OLED display as well as it gives real-time messages or instructions as needed. It is a platform for creativity, education, and innovation. This platform is applicable for a wide range of uses such as in educational institutions or generative applications in technology and art.



Arduino to Servo:

  • Signal (usually orange or yellow wire): Connect to Digital Pin 9 on the Arduino.
  • VCC (usually red wire): Connect to 5V on the Arduino.
  • GND (usually brown or black wire): Connect to GND on the Arduino.

Arduino to OLED:

  • VCC: Connect to 3.3V or 5V on the Arduino (check your display’s voltage rating).
  • GND: Connect to GND on the Arduino.
  • SCL: Connect to A5 on the Arduino.
  • SDA: Connect to A4 on the Arduino.
See also  Arduino IR Remote Control Display

Additional Notes

  • Power Considerations: If your servo draws a lot of current or if you observe erratic behavior, consider using an external power supply for the servo, making sure to connect the grounds (external power supply and Arduino).
  • Library Compatibility: Ensure you have installed the Adafruit_GFX and Adafruit_SH110X libraries through the Arduino IDE Library Manager to compile this sketch successfully.
  • Display and Servo Libraries: Both libraries use hardware resources (I2C bus for the display and timer for the servo), which are generally compatible. However, be aware that using multiple libraries may lead to conflicts, especially on resource-constrained boards.


#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SH110X.h>
#include <Servo.h>

#define i2c_Address 0x3c // Initialize with the I2C addr 0x3C Typically eBay OLED's

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define OLED_RESET -1    // QT-PY / XIAO
Adafruit_SH1106G display = Adafruit_SH1106G(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

Servo myservo;  // Create servo object to control a servo

int textX = SCREEN_WIDTH; // Start text off screen to the right
String message = "Visit CIRCUITROCKS FB PAGE"; // Text to animate

void setup() {

  display.begin(i2c_Address, true); // Address 0x3C default
  delay(2000); // Wait for the OLED to power up

  myservo.attach(9);  // Attaches the servo on pin 9 to the servo object

void loop() {
  rotateServo("CW", 180);
  for(int i = 0; i < 20; i++) animateText(); // Animate text for a period
  rotateServo("Stop", 90);
  for(int i = 0; i < 10; i++) animateText(); // Continue animation during pause
  rotateServo("CCW", 0);
  for(int i = 0; i < 20; i++) animateText(); // Animate text for a period
  rotateServo("Stop", 90);
  for(int i = 0; i < 10; i++) animateText(); // Continue animation during pause

void rotateServo(String direction, int speedCode) {
  myservo.write(speedCode); // Control the servo based on the speedCode

  // Update the display with servo direction and speed code only when changing direction
  display.print("Servo Direction: ");
  display.print("Speed Code: ");

void animateText() {
  // Clear only the lower part of the display to preserve servo information
  display.fillRect(0, 16, SCREEN_WIDTH, SCREEN_HEIGHT - 16, SH110X_BLACK);

  display.setCursor(textX, 30); // Adjust Y position as needed

  // Update text position for scrolling effect
  textX -= 2; // Adjust speed of text scrolling
  if (textX < -((int)message.length() * 6)) { // Reset text position after it scrolls off
    textX = SCREEN_WIDTH;

  delay(100); // Delay to slow down the text animation


OLED Display Issues

  • Check Wiring: Confirm that the SDA and SCL wires are connected to the correct pins on the Arduino. For Arduino Uno, SDA is A4, and SCL is A5.
  • Verify Power Supply: Make sure the OLED’s VCC and GND are properly connected to the Arduino’s 5V and GND.
  • I2C Address: Ensure the OLED’s I2C address in the code (0x3C) matches the actual device address. Use an I2C scanner sketch to confirm the address if unsure.
  • Library Installation: Confirm that the Adafruit_GFX and Adafruit_SH110X libraries are correctly installed through the Arduino IDE.
  • Power Supply Issues: The Arduino’s 5V pin might not provide enough current, especially when powering both the display and a servo. Try using an external power supply or a powered USB hub.
See also  Self Balancing Robot

Servo Motor Issues

  • Pin Assignment: Ensure the servo’s signal wire is connected to the correct pin defined in your code (9).
  • Power Supply: Servos can draw a considerable amount of current. If the servo is not moving, it might be due to insufficient power. Use an external power source for the servo, remembering to connect the grounds.
  • Interference from OLED: Both the OLED display and servo might be trying to draw too much power from the Arduino, causing voltage drops. Again, using an external power source for the servo can help.
  • Code Logic: Double-check the logic in rotateServo. Using myservo.write(speedCode); implies setting the servo to a specific angle. Misinterpretation of speedCode as a speed rather than an angle could cause confusion.