Qwiic EEPROM Hookup Guide

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Contributors: Santa Claus Impersonator, MAKIN-STUFF
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Python Package

Note: This tutorial assumes you are using the latest version of Python 3. If this is your first time using Python or I2C hardware on a Raspberry Pi, please checkout our tutorial on Python Programming with the Raspberry Pi and the Raspberry Pi SPI and I2C Tutorial. Jetson Nano users can check out this tutorial on Working with Qwiic on a Jetson Nano through Jupyter Notebooks.

We've written a Python package to easily get setup and read/write data on the SparkFun Qwiic EEPROM Breakout - 512Kbit. There are two methods for installing the Python package for the Qwiic EEPROM.

  1. Install the all inclusive SparkFun Qwiic Python package.
  2. Independently install the Python package for SparkFun Qwiic EEPROM.

The all inclusive SparkFun Qwiic Python package, is recommended as is also installs the required I2C driver as well.

Note: Don't forget to double check that the hardware I2C connection is enabled on your single board computer.

SparkFun Qwiic Package

This repository is hosted on PyPi as the sparkfun-qwiic package. On systems that support PyPi installation via pip3 (use pip for Python 2) is simple, using the following commands:

For all users (note: the user must have sudo privileges):

language:bash
sudo pip3 install sparkfun-qwiic

For the current user:

language:bash
pip3 install sparkfun-qwiic

Independent Installation

You can install the sparkfun-qwiic-eeprom Python package independently, which is hosted by PyPi. However, if you prefer to manually download and install the package from the GitHub repository, you can grab them here (*Please be aware of any package dependencies. You can also check out the repository documentation page, hosted on ReadtheDocs.):

PyPi Installation

This repository is hosted on PyPi as the sparkfun-qwiic-eeprom package. On systems that support PyPi installation via pip3 (use pip for Python 2) is simple, using the following commands:

For all users (note: the user must have sudo privileges):

language:bash
sudo pip3 install sparkfun-qwiic-eeprom

For the current user:

language:bash
pip3 install sparkfun-qwiic-eeprom

Local Installation

To install, make sure the setuptools package is installed on the system.

Direct installation at the command line (use python for Python 2):

language:bash
python3 setup.py install

To build a package for use with pip3:

language:bash
python3 setup.py sdist

A package file is built and placed in a subdirectory called dist. This package file can be installed using pip3.

language:bash
cd dist
pip3 install sparkfun_qwic_eeprom-<version>.tar.gz

Python Package Operation

Before we jump into getting readings, let's take a closer look at the available functions in the Python package. Below, is a description of the basic functionality of the Python package. This includes the package organization, built-in methods, and their inputs and/or outputs. For more details on how the Python package works, check out the source code and package documentation.

Dependencies

This Python package has a very few dependencies in the code, listed below:

language:python
import math
import time
import qwiic_i2c
import smbus2
import struct

Default Variables

The default variables, in the code, for this Python package are listed below:

language:python
# qwiic_eeprom GLOBAL VARIABLES
#----------------------------------------------------------------------------------------------------
# Define the device name and I2C addresses. These are set in the class defintion 
# as class variables, making them avilable without having to create a class instance.
# This allows higher level logic to rapidly create a index of qwiic devices at 
# runtine

# The name of this device 
_DEFAULT_NAME = "Qwiic EEPROM"

# Some devices have multiple availabele addresses - this is a list of these addresses.
# NOTE: The first address in this list is considered the default I2C address for the 
# device.
_AVAILABLE_I2C_ADDRESS = [0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57]
Note: This package is different from previous packages as the local variables are declared in the object class.
language:python
# QwiicEEPROM CLASS VARIABLES
#----------------------------------------------------------------------------------------------------
memory_size_bytes = 512000 / 8
page_size_bytes = 64
page_write_time_ms = 5
poll_for_write_complete = True

I2C_BUFFER_LENGTH = 32

Class

QwiicEEPROM() or QwiicEEPROM(address)
This Python package operates as a class object, allowing new instances of that type to be made. An __init__() constructor is used that creates a connection to an I2C device over the I2C bus using the default or specified I2C address.

The Constructor

A constructor is a special kind of method used to initialize (assign values to) the data members needed by the object when it is created.

__init__(address=None, i2c_driver=None):

Input: value
The value of the device address. If not defined, the Python package will use the default I2C address (0x50) stored under _AVAILABLE_I2C_ADDRESS variable.
Input: i2c_driver
Loads the specified I2C driver; by default the Qwiic I2C driver is used: qwiic_i2c.getI2CDriver(). Users should use the default I2C driver and leave this field blank.

Functions

A function is an attribute of the class, which defines a method for instances of that class. In simple terms, they are objects for the operations (or methods) of the class. A list of all the available functions are detailed on the API Reference page of ReadtheDocs for the Qwiic_EEPROM_Py Python package.

Upgrading the Python Package

In the future, changes to the Python package might be made. Updating the installed packages has to be done individually for each package (i.e. sub-modules and dependencies won't update automatically and must be updated manually). For the sparkfun-qwiic-eeprom Python package, use the following command (use pip for Python 2):

For all users (note: the user must have sudo privileges):

language:bash
sudo pip3 install --upgrade sparkfun-qwiic-eeprom

For the current user:

language:bash
pip3 install --upgrade sparkfun-qwiic-eeprom