Arduino - OLED Clock

In this tutorial, we are going to learn how to make OLED clock by:

Or

You can choose one of two RTC modules: DS3231 and DS1307. See DS3231 vs DS1307

Hardware Required

1×Arduino UNO or Genuino UNO
1×USB 2.0 cable type A/B
1×SSD1306 I2C OLED Display 128x64
1×Real-Time Clock DS3231 Module
Or 1×Real-Time Clock DS1307 Module
1×CR2032 battery
1×Breadboard
4×Jumper Wires
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About OLED, DS3231 and DS1307 RTC module

If you do not know about OLED, DS3231 and DS1307 (pinout, how it works, how to program ...), learn about them in the following tutorials:

Install OLED and RTC Libraries

  • On Arduino IDE, Go to Tools Manage Libraries
  • Arduino add library
  • Search “SSD1306”, then find the SSD1306 library by Adafruit
  • Click Install button to install the library.
  • Arduino OLED library
  • You will be asked for intalling some other library dependencies
  • Click Install All button to install all library dependencies.
  • Arduino Adafruit GFX sensor library
  • Search “RTClib”, then find the RTC library by Adafruit. This library works with both DS3231 and DS1307
  • Click Install button to install RTC library.
  • Arduino RTC library

Reading time from DS3231 RTC module and display it on OLED

Wiring Diagram

Arduino DS3231 OLED Wiring Diagram

Image is developed using Fritzing. Click to enlarge image

Arduino Code - DS3231 and OLED

/* * Created by ArduinoGetStarted.com * * This example code is in the public domain * * Tutorial page: https://arduinogetstarted.com/tutorials/arduino-oled-clock */ #include <Wire.h> #include <Adafruit_GFX.h> #include <Adafruit_SSD1306.h> #include <RTClib.h> #define SCREEN_WIDTH 128 // OLED display width, in pixels #define SCREEN_HEIGHT 64 // OLED display height, in pixels Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1); // // create SSD1306 display object connected to I2C RTC_DS3231 rtc; String time; void setup() { Serial.begin(9600); // initialize OLED display with address 0x3C for 128x64 if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { Serial.println(F("SSD1306 allocation failed")); while (true); } delay(2000); // wait for initializing oled.clearDisplay(); // clear display oled.setTextSize(1); // text size oled.setTextColor(WHITE); // text color oled.setCursor(0, 10); // position to display // SETUP RTC MODULE if (! rtc.begin()) { Serial.println("Couldn't find RTC"); Serial.flush(); while (true); } // automatically sets the RTC to the date & time on PC this sketch was compiled rtc.adjust(DateTime(F(__DATE__), F(__TIME__))); time.reserve(10); // to avoid fragmenting memory when using String } void loop() { DateTime now = rtc.now(); time = ""; time += now.hour(); time += ':'; time += now.minute(); time += ':'; time += now.second(); oledDisplayCenter(time); } void oledDisplayCenter(String text) { int16_t x1; int16_t y1; uint16_t width; uint16_t height; oled.getTextBounds(text, 0, 0, &x1, &y1, &width, &height); // display on horizontal and vertical center oled.clearDisplay(); // clear display oled.setCursor((SCREEN_WIDTH - width) / 2, (SCREEN_HEIGHT - height) / 2); oled.println(text); // text to display oled.display(); }

Quick Steps

  • Copy the above code and open with Arduino IDE
  • Click Upload button on Arduino IDE to upload code to Arduino
  • Put the sensor on hot and cold water, or grasp the sensor by your hand
  • See the result on OLED

Reading time from DS1307 RTC module and display it on OLED

Wiring Diagram

Arduino DS1307 OLED Wiring Diagram

Image is developed using Fritzing. Click to enlarge image

Arduino Code - DS1307 and OLED

/* * Created by ArduinoGetStarted.com * * This example code is in the public domain * * Tutorial page: https://arduinogetstarted.com/tutorials/arduino-oled-clock */ #include <Wire.h> #include <Adafruit_GFX.h> #include <Adafruit_SSD1306.h> #include <RTClib.h> #define SCREEN_WIDTH 128 // OLED display width, in pixels #define SCREEN_HEIGHT 64 // OLED display height, in pixels Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1); // // create SSD1306 display object connected to I2C RTC_DS1307 rtc; String time; void setup() { Serial.begin(9600); // initialize OLED display with address 0x3C for 128x64 if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { Serial.println(F("SSD1306 allocation failed")); while (true); } delay(2000); // wait for initializing oled.clearDisplay(); // clear display oled.setTextSize(1); // text size oled.setTextColor(WHITE); // text color oled.setCursor(0, 10); // position to display // SETUP RTC MODULE if (! rtc.begin()) { Serial.println("Couldn't find RTC"); Serial.flush(); while (true); } // automatically sets the RTC to the date & time on PC this sketch was compiled rtc.adjust(DateTime(F(__DATE__), F(__TIME__))); time.reserve(10); // to avoid fragmenting memory when using String } void loop() { DateTime now = rtc.now(); time = ""; time += now.hour(); time += ':'; time += now.minute(); time += ':'; time += now.second(); oledDisplayCenter(time); } void oledDisplayCenter(String text) { int16_t x1; int16_t y1; uint16_t width; uint16_t height; oled.getTextBounds(text, 0, 0, &x1, &y1, &width, &height); // display on horizontal and vertical center oled.clearDisplay(); // clear display oled.setCursor((SCREEN_WIDTH - width) / 2, (SCREEN_HEIGHT - height) / 2); oled.println(text); // text to display oled.display(); }

Quick Steps

  • Copy the above code and open with Arduino IDE
  • Click Upload button on Arduino IDE to upload code to Arduino
  • Put the sensor on hot and cold water, or grasp the sensor by your hand
  • See the result on OLED

Video Tutorial

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