ESP32 PCF8563 Real-Time Clock (RTC)

Code Examples

Below you can find code examples of PCF8563 Real-Time Clock (RTC) with ESP32 in several frameworks:

• Arduino IDE
• ESP-IDF
• ESPHome
• PlatformIO
• MicroPython

ESP32 PCF8563 Arduino IDE Code Example

Example in Arduino IDE

Fill in your main Arduino IDE sketch file with the following code to use the PCF8563 Real-Time Clock (RTC):

#include <Wire.h>
#include <Rtc_Pcf8563.h>

Rtc_Pcf8563 rtc;

void setup() {
    Serial.begin(9600);
    Wire.begin(21, 22); // SDA: GPIO21, SCL: GPIO22
    rtc.initClock();
    rtc.setDate(4, 12, 2023); // DD, MM, YYYY
    rtc.setTime(14, 30, 0);   // HH, MM, SS
}

void loop() {
    Serial.print("Time: ");
    Serial.print(rtc.getHour());
    Serial.print(":");
    Serial.print(rtc.getMinute());
    Serial.print(":");
    Serial.println(rtc.getSecond());
    Serial.print("Date: ");
    Serial.print(rtc.getDay());
    Serial.print("/");
    Serial.print(rtc.getMonth());
    Serial.print("/");
    Serial.println(rtc.getYear());
    delay(1000);
}

This Arduino sketch interfaces with the PCF8563 RTC module using the Rtc_Pcf8563 library and the specified pin configuration (SDA: GPIO21, SCL: GPIO22). In the setup(), the RTC is initialized and the date and time are set. The loop() retrieves and prints the current time and date to the Serial Monitor every second.

Connect your ESP32 to your computer via a USB cable, Ensure the correct Board and Port are selected under Tools, Click the "Upload" button in the Arduino IDE to compile and upload the code to your ESP32.

ESP32 PCF8563 ESP-IDF Code Example

Example in Espressif IoT Framework (ESP-IDF)

If you're using ESP-IDF to work with the PCF8563 Real-Time Clock (RTC), here's how you can set it up and read data from the sensor. Fill in this code in the main ESP-IDF file:

#include <stdio.h>
#include "driver/i2c.h"
#include "pcf8563.h"

#define I2C_MASTER_SCL_IO 22
#define I2C_MASTER_SDA_IO 21

void app_main(void) {
    i2c_config_t i2c_config = {
        .mode = I2C_MODE_MASTER,
        .sda_io_num = I2C_MASTER_SDA_IO,
        .scl_io_num = I2C_MASTER_SCL_IO,
        .sda_pullup_en = GPIO_PULLUP_ENABLE,
        .scl_pullup_en = GPIO_PULLUP_ENABLE,
        .master.clk_speed = 100000
    };
    i2c_param_config(I2C_NUM_0, &i2c_config);
    i2c_driver_install(I2C_NUM_0, I2C_MODE_MASTER, 0, 0, 0);

    pcf8563_init(I2C_NUM_0);
    pcf8563_set_datetime(2023, 12, 4, 14, 30, 0);

    while (1) {
        pcf8563_datetime_t now;
        pcf8563_get_datetime(&now);
        printf("Time: %02d:%02d:%02d\n", now.hour, now.minute, now.second);
        printf("Date: %04d/%02d/%02d\n", now.year, now.month, now.day);
        vTaskDelay(pdMS_TO_TICKS(1000));
    }
}

This ESP-IDF example interfaces with the PCF8563 RTC over I2C, with SDA connected to GPIO21 and SCL to GPIO22. The RTC is initialized, and the date and time are set using pcf8563_set_datetime(). The current time and date are fetched using pcf8563_get_datetime() and printed to the console every second.

Update the I2C pins (I2C_MASTER_SDA_IO and I2C_MASTER_SCL_IO) to match your ESP32 hardware setup, Use idf.py build to compile the project, Use idf.py flash to upload the code to your ESP32.

ESP32 PCF8563 ESPHome Code Example

Example in ESPHome (Home Assistant)

Fill in this configuration in your ESPHome YAML configuration file (example.yml) to integrate the PCF8563 Real-Time Clock (RTC)

i2c:
  sda: GPIO21
  scl: GPIO22

time:
  - platform: pcf8563
    id: pcf8563_time
    update_interval: 1s

sensor:
  - platform: custom
    lambda: |-
      auto my_sensor = new PCF8563Sensor(id(pcf8563_time));
      return {my_sensor};
    sensors:
      - name: "PCF8563 Date and Time"

The ESPHome configuration sets up I2C communication with the PCF8563 RTC using SDA on GPIO21 and SCL on GPIO22. The time platform fetches time and date information at 1-second intervals, and a custom sensor displays the data in a human-readable format.

Upload this code to your ESP32 using the ESPHome dashboard or the esphome run command.

ESP32 PCF8563 PlatformIO Code Example

Example in PlatformIO Framework

For PlatformIO, make sure to configure the platformio.ini file with the appropriate environment and libraries, and then proceed with the code.

Configure platformio.ini

First, your platformio.ini should look like below. You might need to include some libraries as shown. Make sure to change the board to your ESP32:

[env:esp32dev]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200

ESP32 PCF8563 PlatformIO Example Code

Write this code in your PlatformIO project under the src/main.cpp file to use the PCF8563 Real-Time Clock (RTC):

#include <Wire.h>
#include <Rtc_Pcf8563.h>

Rtc_Pcf8563 rtc;

void setup() {
    Serial.begin(115200);
    Wire.begin(21, 22); // SDA: GPIO21, SCL: GPIO22
    rtc.initClock();
    rtc.setDate(4, 12, 2023); // DD, MM, YYYY
    rtc.setTime(14, 30, 0);   // HH, MM, SS
}

void loop() {
    Serial.print("Time: ");
    Serial.print(rtc.getHour());
    Serial.print(":");
    Serial.print(rtc.getMinute());
    Serial.print(":");
    Serial.println(rtc.getSecond());
    Serial.print("Date: ");
    Serial.print(rtc.getDay());
    Serial.print("/");
    Serial.print(rtc.getMonth());
    Serial.print("/");
    Serial.println(rtc.getYear());
    delay(1000);
}

This PlatformIO code interfaces with the PCF8563 RTC using the specified pin configuration (SDA: GPIO21, SCL: GPIO22). The RTC is initialized and configured in the setup(), while the loop() fetches and prints the current time and date every second.

Upload the code to your ESP32 using the PlatformIO "Upload" button in your IDE or the pio run --target upload command.

ESP32 PCF8563 MicroPython Code Example

Example in Micro Python Framework

Fill in this script in your MicroPython main.py file (main.py) to integrate the PCF8563 Real-Time Clock (RTC) with your ESP32.

from machine import I2C, Pin
import time

# PCF8563 I2C address
PCF8563_ADDRESS = 0x51

def bcd_to_decimal(bcd):
    return (bcd >> 4) * 10 + (bcd & 0x0F)

def decimal_to_bcd(decimal):
    return ((decimal // 10) << 4) | (decimal % 10)

def set_time(i2c, year, month, day, hour, minute, second):
    data = [decimal_to_bcd(second), decimal_to_bcd(minute), decimal_to_bcd(hour),
            0, decimal_to_bcd(day), decimal_to_bcd(month), decimal_to_bcd(year - 2000)]
    i2c.writeto_mem(PCF8563_ADDRESS, 0x02, bytes(data))

def get_time(i2c):
    data = i2c.readfrom_mem(PCF8563_ADDRESS, 0x02, 7)
    second = bcd_to_decimal(data[0] & 0x7F)
    minute = bcd_to_decimal(data[1] & 0x7F)
    hour = bcd_to_decimal(data[2] & 0x3F)
    day = bcd_to_decimal(data[3] & 0x3F)
    month = bcd_to_decimal(data[5] & 0x1F)
    year = bcd_to_decimal(data[6]) + 2000
    return year, month, day, hour, minute, second

# Initialize I2C
i2c = I2C(0, scl=Pin(22), sda=Pin(21))

# Set initial time
set_time(i2c, 2023, 12, 4, 14, 30, 0)

# Loop to read time
while True:
    year, month, day, hour, minute, second = get_time(i2c)
    print(f"Time: {hour:02}:{minute:02}:{second:02}, Date: {year:04}/{month:02}/{day:02}")
    time.sleep(1)

This MicroPython script communicates with the PCF8563 RTC over I2C using SDA (GPIO21) and SCL (GPIO22). The set_time() function initializes the RTC with the specified time and date, while the get_time() function reads and decodes the current time and date. In the loop, the script continuously fetches and prints the current time and date every second.

Upload this code to your ESP32 using a MicroPython-compatible IDE, such as Thonny, uPyCraft, or tools like ampy.