The DS3231 is a highly accurate, low-cost real-time clock (RTC) module with an integrated temperature-compensated crystal oscillator (TCXO) and crystal. It maintains seconds, minutes, hours, day, date, month, and year information, with automatic adjustment for leap years and months with fewer than 31 days. The module communicates with a microcontroller via I2C protocol.
This circuit connects an ESP32 Devkit V1 microcontroller with an RTC DS3231 real-time clock module. The ESP32 provides power to the RTC and communicates with it via I2C, with D21 and D22 serving as the data (SDA) and clock (SCL) lines, respectively. The common ground (GND) ensures a reference point for the voltages, and the 3V3 pin from the ESP32 powers the RTC module.
Open Project in Cirkit Designer
This circuit integrates two RTC DS3231 real-time clock modules with a Glyph C3 microcontroller. The RTC modules are connected to the microcontroller via I2C communication protocol, using the SCL and SDA lines for clock and data respectively. Both RTC modules and the microcontroller share a common power supply (3V3) and ground (GND), indicating that they operate at the same voltage level.
Open Project in Cirkit Designer
This circuit connects an ESP32 microcontroller to a DS3231 Real Time Clock (RTC) module. The ESP32's Vin and GND pins are connected to the VCC and GND pins of the DS3231, providing power to the RTC. The SCL and SDA pins of the DS3231 are connected to the D22 and D21 pins of the ESP32, respectively, enabling I2C communication between the microcontroller and the RTC module.
Open Project in Cirkit Designer
This circuit connects an Arduino UNO microcontroller with a DS3231 Real Time Clock (RTC) module. The Arduino provides 5V power and ground to the RTC and communicates with it via the I2C protocol using the A4 (SDA) and A5 (SCL) pins. The embedded code on the Arduino is used to initialize the RTC, check for power loss, set the current time if needed, and periodically read and print the current time to the serial monitor.
Open Project in Cirkit Designer| Pin Number | Name | Description |
|---|---|---|
| 1 | VCC | Power supply (2.3V to 5.5V) |
| 2 | GND | Ground connection |
| 3 | SDA | Serial Data Line for I2C communication |
| 4 | SCL | Serial Clock Line for I2C communication |
| 5 | SQW | Square Wave/Interrupt Output |
| 6 | 32K | 32kHz Output |
| 7 | RST | Reset Input (Active Low) |
#include <Wire.h>
#include <RTClib.h>
RTC_DS3231 rtc;
void setup() {
Serial.begin(9600);
// Check if the RTC is connected correctly
if (!rtc.begin()) {
Serial.println("Couldn't find RTC");
while (1);
}
// Check if the RTC lost power and if so, set the time
if (rtc.lostPower()) {
Serial.println("RTC lost power, let's set the time!");
// The following line sets the RTC to the date & time this sketch was compiled
rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
}
}
void loop() {
DateTime now = rtc.now();
// Print the current date and time
Serial.print(now.year(), DEC);
Serial.print('/');
Serial.print(now.month(), DEC);
Serial.print('/');
Serial.print(now.day(), DEC);
Serial.print(" ");
Serial.print(now.hour(), DEC);
Serial.print(':');
Serial.print(now.minute(), DEC);
Serial.print(':');
Serial.print(now.second(), DEC);
Serial.println();
delay(1000);
}
Wire library's setClock() function to adjust I2C clock speed if communication issues arise.