RTC Pi Python Library

Python Library to use with RTC Pi Raspberry Pi real-time clock board.

The example python files can be found in /ABElectronics_Python_Libraries/RTCPi/demos

Downloading and Installing the library

To download to your Raspberry Pi type in the terminal:

git clone https://github.com/abelectronicsuk/ABElectronics_Python_Libraries.git

To install the python library navigate into the ABElectronics_Python_Libraries folder and run:

For Python 2.7:

sudo python setup.py install

For Python 3:

sudo python3 setup.py install

If you have PIP installed you can install the library directly from GitHub with the following command:

For Python 2.7:

sudo python2.7 -m pip install git+https://github.com/abelectronicsuk/ABElectronics_Python_Libraries.git

For Python 3:

sudo python3 -m pip install git+https://github.com/abelectronicsuk/ABElectronics_Python_Libraries.git

The RTC Pi library is located in the RTCPi directory

The library requires smbus2 or python-smbus to be installed.

For Python 2.7:

sudo pip install smbus2

For Python 3:

sudo pip3 install smbus2

Class:

RTC(bus)

Parameters:
bus (optional): I2C bus number (integer). If no value is set the class will try to find the i2c bus automatically using the device name.

Functions:

set_date(date) 

Set the date and time on the RTC in ISO 8601 format - YYYY-MM-DDTHH:MM:SS
Parameters: date
Returns: null

read_date() 

Returns the date from the RTC in ISO 8601 format - YYYY-MM-DDTHH:MM:SS
Returns: date

enable_output() 

Enable the square-wave output on the SQW pin.
Returns: null

disable_output()

Disable the square-wave output on the SQW pin.
Returns: null

set_frequency(frequency)

Set the frequency for the square-wave output on the SQW pin.
Parameters: frequency - options are: 1 = 1Hz, 2 = 4.096KHz, 3 = 8.192KHz, 4 = 32.768KHz
Returns: null

write_memory(address, valuearray)

Write to the memory on the ds1307. The ds1307 contains 56-Byte, battery-backed RAM with Unlimited Writes
Parameters: address - 0x08 to 0x3F
valuearray - byte array containing data to be written to memory
Returns: null

read_memory(address, length)

Read from the memory on the ds1307
Parameters: address - 0x08 to 0x3F length - up to 32 bytes.
length can not exceed the available address space.
Returns: array of bytes

Usage

To use the RTC Pi library in your code you must first import the library:

from RTCPi import RTC

Next, you must initialise the RTC object:

rtc = RTC()

Set the current time in ISO 8601 format:

rtc.set_date("2013-04-23T12:32:11")

Enable the square-wave output at 8.192KHz on the SQW pin:

rtc.set_frequency(3)
rtc.enable_output()

Read the current date and time from the RTC at 1-second intervals:

while (True):
  print rtc.read_date()
  time.sleep(1)