MicroPython DS1302 RTC Driver
April 26, 2025 ยท View on GitHub
A pure MicroPython driver for the DS1302 real-time clock (RTC) module.
Table of Contents
Overview
The DS1302 is a real-time clock (RTC) integrated circuit with a simple serial interface and 31 bytes of battery-backed SRAM. It keeps track of second, minute, hour, day, day of the week, month, and year with leap-year compensation up to the year 2100.
This project provides a pure MicroPython driver to interface with the DS1302 module.
Hardware
- Chip: DS1302
- Voltage: 2.0V to 5.5V
- Battery backup: CR2032 or similar 3V lithium cell
- RAM: 31 bytes battery-backed SRAM
- Features:
- Serial I/O communication
- Trickle-charge capability for backup supply
- Timekeeping accurate up to the year 2100
- Low power operation
Pinout
| Pin Name | Description |
|---|---|
| VCC | Power Supply |
| GND | Ground |
| CLK | Serial Clock Input |
| DAT | Serial Data I/O |
| RST | Reset (Enable) |
The driver requires connection to the CLK, DAT, and RST pins for operation.
Installation
Copy the ds1302.py file into your MicroPython device's filesystem.
API Reference
-
DS1302(clk, dat, rst)- Initialize the DS1302 with clock, data, and reset pins.
-
start()- Start the RTC.
-
stop()- Stop/pause the RTC.
-
get_date_time()/set_date_time(date_time)- Get or set the full date and time.
get_date_time(): Returns[year, month, day, weekday, hour, minute, second].set_date_time(list): Sets the datetime.
-
Getters/Setters for individual components:
get_year()/set_year(value)get_month()/set_month(value)get_day()/set_day(value)get_weekday()/set_weekday(value)get_hour()/set_hour(value)get_minute()/set_minute(value)get_second()/set_second(value)
-
RAM Access:
get_ram(register)set_ram(register, value)
Example Usage
from ds1302 import DS1302
from machine import Pin # type: ignore[import]
# Initialize DS1302 RTC with the appropriate GPIO pins
rtc = DS1302(clk=Pin(0), dat=Pin(1), rst=Pin(2))
# Set the date and time: [year, month, day, weekday, hour, minute, second]
# Eg. 2025-04-26 14:30:00, Saturday (6th day of the week)
rtc.set_date_time([2025, 4, 26, 6, 14, 30, 0])
# Alternatively, set the date and time using individual components
rtc.set_year(2084)
# Read the full date and time
print("Current date and time:", rtc.get_date_time())
# Read individual components
year = rtc.get_year()
month = rtc.get_month()
day = rtc.get_day()
weekday = rtc.get_weekday()
hour = rtc.get_hour()
minute = rtc.get_minute()
second = rtc.get_second()
print(f"Year: {year}, Month: {month}, Day: {day}, Weekday: {weekday}")
print(f"Time: {hour:02}:{minute:02}:{second:02}")
# Save a 1-byte value into RAM
rtc.set_ram(register=30, value=255)
# Read the value back from RAM register
ram_reg_30 = rtc.get_ram(register=30)
print("Value from RAM:", ram_reg_30)
Acknowledgements
Thanks to previous contributors: