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MicroPython AM2320 I2C

A MicroPython library for interfacing with an Aosong AM2320 temperature and humidity sensor over I2C.

This library focuses on using the I2C interface. The sensor also supports a 1-wire interface, available when pin 4 is connected to GND.

demo

Installation

Using mip via mpremote:

$ mpremote mip install github:mcauser/micropython-am2320
$ mpremote mip install github:mcauser/micropython-am2320/examples

Using mip directly on a WiFi capable board:

>>> import mip
>>> mip.install("github:mcauser/micropython-am2320")
>>> mip.install("github:mcauser/micropython-am2320/examples")

Manual installation:

Copy src/am2320.py to the root directory of your device.

Examples

Basic usage

from machine import I2C, Pin
import am2320

i2c = I2C(0)
sensor = am2320.AM2320(i2c)

sensor.measure()
print(sensor.temperature())
print(sensor.humidity())

Methods

init(i2c)

As with other modern Aosong sensors, this sensor supports an I2C interface and can be found at address 0x5C.

check()

Scans the I2C bus looking for the sensor at it's fixed I2C address 0x5C. Raises a OSError if not found.

measure()

Reads the temperature and humidity from the sensor over the I2C bus and persists for subsequent calls to temperature() and humidity(). Received bytes contains a checksum to ensure the data is error free, otherwise an exception is raised.

temperature()

Returns the temperature in degrees Celsius from the data collected from the last measure() call.

humidity()

Get the relative humidity as a percentage from the data collected from the last measure() call.

_wake()

The sensor goes into sleep mode when idle to help minimise influencing the readings and requires writing a byte to wake it back up. The write will fail, however the sensor interprets it as a wake up call.

_crc16(buf)

A 16-bit cyclic redundancy check for verifying the received data is error free.

Parts

Connections

AM2320	TinyPICO (ESP32)
VIN	3V3
SDA	22
GND	GND
SCL	21

AM2320	Wemos D1 Mini (ESP8266)
VIN	3V3
SDA	GPIO4
GND	GND
SCL	GPIO5

License

Licensed under the MIT License.