It's easy to use the AM2315 sensor with Python or CircuitPython and the Adafruit CircuitPython AM2320 module. That's not a typo! The CircuitPython AM2320 library works perfectly with the AM2315 sensor. This module allows you to easily write Python code that reads the humidity and temperature from the sensor.

You can use this sensor with any CircuitPython microcontroller board or with a computer that has GPIO and Python thanks to Adafruit_Blinka, our CircuitPython-for-Python compatibility library.

One thing to watch out for with the AM2315 is that it goes into 'sleep' mode, you may find if you are scanning the i2c bus that the device does not appear - try scanning again and it will appear the second time!

CircuitPython Microcontroller Wiring

First wire up a AM2315 to your board using an I2C connection.  Here's an example of wiring a Feather M0 to the sensor with I2C, don't forget to add pull-ups for the I2C lines to 3.3V

  • Board 3V to sensor VIN (red wire)
  • Board GND to sensor GND (black wire)
  • Board SCL to sensor SCL (white wire)
  • Board SDA to sensor SDA (yellow wire)

Python Computer Wiring

Since there's dozens of Linux computers/boards you can use we will show wiring for Raspberry Pi. For other platforms, please visit the guide for CircuitPython on Linux to see whether your platform is supported

Here's the Raspberry Pi wired with I2C:

  • Pi 3V3 to sensor VIN (red wire)
  • Pi GND to sensor GND (black wire)
  • Pi SCL to sensor SCL (white wire)
  • Pi SDA to sensor SDA (yellow wire)
The Raspberry Pi has built-in pull up resistors on SDA/SCL so we don't include them here. If you are using some other computer, check if you need to add your own 2-10K pullups to 3.3V!
At this time this sensor does not appear to work well on the Raspberry Pi. We’ve seen mixed success, but YMMV.

CircuitPython Installation of AM2320 Library

Next you'll need to install the Adafruit CircuitPython AM2320 library on your CircuitPython board. Even though the library is called the AM2320 it also works on AM2315s! Remember, even though you're using the AM2315 sensor, you'll be using the AM2320 library.

First make sure you are running the latest version of Adafruit CircuitPython for your board.

Next you'll need to install the necessary libraries to use the hardware--carefully follow the steps to find and install these libraries from Adafruit's CircuitPython library bundle.  Our introduction guide has a great page on how to install the library bundle for both express and non-express boards.

For non-express boards like the Trinket M0 or Gemma M0, you'll need to manually install the necessary libraries from the bundle:

  • adafruit_am2320.mpy
  • adafruit_bus_device

You can also download the adafruit_am2320.mpy from its releases page on Github.

Before continuing make sure your board's lib folder or root filesystem has the adafruit_am2320.mpy, and adafruit_bus_device files and folders copied over.

We suggest using Mu as a code editor as it includes serial access to the REPL and more.

Next connect to the board's serial REPL so you are at the CircuitPython >>> prompt.

Python Installation of AM2320 Library

You'll need to install the Adafruit_Blinka library that provides the CircuitPython support in Python. This may also require enabling I2C on your platform and verifying you are running Python 3. Since each platform is a little different, and Linux changes often, please visit the CircuitPython on Linux guide to get your computer ready!

Once that's done, from your command line run the following command:

  • sudo pip3 install adafruit-circuitpython-am2320

Remember, even though you're using the AM2315 sensor, you'll be using the AM2320 library.

If your default Python is version 3 you may need to run 'pip' instead. Just make sure you aren't trying to use CircuitPython on Python 2.x, it isn't supported!

CircuitPython & Python Usage

To demonstrate the usage of the sensor we'll initialize it and read the humidity and temperature from the board's Python REPL.

Run the following code to import the necessary modules and initialize the I2C connection with the sensor:

import board
import busio
import adafruit_am2320
i2c = busio.I2C(board.SCL, board.SDA)
sensor = adafruit_am2320.AM2320(i2c)

Now you're ready to read values from the sensor using any of these properties:

  • relative_humidity - The relative humidity measured by the sensor, this is a value from 0-100%.
  • temperature - The temperature measured by the sensor, a value in degrees Celsius.

For example, to print the temperature and relative humidity:

print('Humidity: {0}%'.format(sensor.relative_humidity))
print('Temperature: {0}C'.format(sensor.temperature))
If you want to take another reading, wait 2 seconds before requesting temperature or relative_humidity again. Data in the sensor is only updated every 2 seconds!

That's all there is to using the AM2315 with CircuitPython!

Below is a complete example that measures the sensor readings and prints them every two seconds.  Save this as on your board and open the REPL/Serial out to see the output.

Full Example Code

# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT

import time
import board
import adafruit_am2320

# create the I2C shared bus
i2c = board.I2C()  # uses board.SCL and board.SDA
# i2c = board.STEMMA_I2C()  # For using the built-in STEMMA QT connector on a microcontroller
am = adafruit_am2320.AM2320(i2c)

while True:
    print("Temperature: ", am.temperature)
    print("Humidity: ", am.relative_humidity)

This guide was first published on Oct 04, 2018. It was last updated on Jun 11, 2024.

This page (Python & CircuitPython) was last updated on Jun 11, 2024.

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