Introduction¶
This is a great battery-backed real time clock (RTC) that allows your microcontroller project to keep track of time even if it is reprogrammed, or if the power is lost. Perfect for datalogging, clock-building, time stamping, timers and alarms, etc. The DS1307 is the most popular RTC - but it requires 5V power to work.
The DS1307 is simple and inexpensive but not a high precision device. It may lose or gain up to two seconds a day. For a high-precision, temperature compensated alternative, please check out the DS3231 precision RTC. If you do not need a DS1307, or you need a 3.3V-power/logic capable RTC please check out our affordable PCF8523 RTC breakout.
Dependencies¶
This driver depends on:
Please ensure all dependencies are available on the CircuitPython filesystem. This is easily achieved by downloading the Adafruit library and driver bundle.
Installing from PyPI¶
On supported GNU/Linux systems like the Raspberry Pi, you can install the driver locally from PyPI. To install for current user:
pip3 install adafruit-circuitpython-ds1307
To install system-wide (this may be required in some cases):
sudo pip3 install adafruit-circuitpython-ds1307
To install in a virtual environment in your current project:
mkdir project-name && cd project-name
python3 -m venv .env
source .env/bin/activate
pip3 install adafruit-circuitpython-ds1307
Usage Notes¶
Of course, you must import the library to use it:
import board
import adafruit_ds1307
import time
All the Adafruit RTC libraries take an instantiated and active I2C object
(from the board library) as an argument to their constructor. The way to
create an I2C object depends on the board you are using. For boards with labeled
SCL and SDA pins, you can:
import board
Now, to initialize the I2C bus:
i2c = board.I2C()
Once you have created the I2C interface object, you can use it to instantiate the RTC object:
rtc = adafruit_ds1307.DS1307(i2c)
To set the time, you need to set datetime to a time.struct_time object:
rtc.datetime = time.struct_time((2017,1,9,15,6,0,0,9,-1))
After the RTC is set, you retrieve the time by reading the datetime
attribute and access the standard attributes of a struct_time such as tm_year,
tm_hour and tm_min.
t = rtc.datetime
print(t)
print(t.tm_hour, t.tm_min)
Contributing¶
Contributions are welcome! Please read our Code of Conduct before contributing to help this project stay welcoming.
Documentation¶
For information on building library documentation, please check out this guide.