Introduction

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The MCP9808 is an awesome, high accuracy temperature sensor that communicates over I2C. Its available on Adafruit as a 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-mcp9808

To install system-wide (this may be required in some cases):

sudo pip3 install adafruit-circuitpython-mcp9808

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-mcp9808

Usage Notes

Getting the temperature in Celsius is easy! First, import all of the pins from the board, board.I2C() for native I2C communication and the thermometer library itself.

from board import *
import adafruit_mcp9808

Next, initialize the I2C bus in a with statement so it always gets shut down ok. Then, construct the thermometer class:

# Do one reading
with i2c = board.I2C() as i2c:
    t = adafruit_mcp9808.MCP9808(i2c)

    # Finally, read the temperature property and print it out
    print(t.temperature)

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.

Table of Contents

Simple test

Ensure your device works with this simple test.

examples/mcp9808_simpletest.py
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# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT

import time
import board
import adafruit_mcp9808

i2c = board.I2C()  # uses board.SCL and board.SDA

# To initialise using the default address:
mcp = adafruit_mcp9808.MCP9808(i2c)

# To initialise using a specified address:
# Necessary when, for example, connecting A0 to VDD to make address=0x19
# mcp = adafruit_mcp9808.MCP9808(i2c_bus, address=0x19)


while True:
    tempC = mcp.temperature
    tempF = tempC * 9 / 5 + 32
    print("Temperature: {} C {} F ".format(tempC, tempF))
    time.sleep(2)

adafruit_mcp9808

CircuitPython library to support MCP9808 high accuracy temperature sensor.

  • Author(s): Scott Shawcroft

Implementation Notes

Hardware:

Software and Dependencies:

Notes:

  1. Datasheet: http://www.adafruit.com/datasheets/MCP9808.pdf
class adafruit_mcp9808.MCP9808(i2c_bus, address=24)[source]

Interface to the MCP9808 temperature sensor.

Parameters:
  • i2c_bus (I2C) – The I2C bus the MCP9808 is connected to.
  • address (int) – The I2C address of the device. Defaults to 0x18

Quickstart: Importing and using the MCP9808

Here is an example of using the MCP9808 class. First you will need to import the libraries to use the sensor

import board
import adafruit_mcp9808

Once this is done you can define your board.I2C object and define your sensor object

i2c = board.I2C()   # uses board.SCL and board.SDA
mcp = adafruit_mcp9808.MCP9808(i2c_bus)

Now you have access to the change in temperature using the temperature attribute. This temperature is in Celsius.

temperature = mcp.temperature
temperature

Temperature in Celsius. Read-only.

Indices and tables