`mlx90614` — Infra-red digital temperature sensor

The MLX90614 is a single and dual-zone infra-red contactless thermometer.

The MLX90614 is factory calibrated in wide temperature ranges:

-40°C to 125°C for the ambient temperature and
-70°C to 380°C for the object temperature.

The measured value is the average temperature of all objects in the Field Of View of the sensor.

The MLX90614 offers a standard accuracy of ±0.5˚C around room temperatures.

The data-sheet may be obtained from https://media.melexis.com/-/media/files/documents/datasheets/mlx90614-datasheet-melexis.pdf

Information about infra-red thermometers in general may be found at https://en.wikipedia.org/wiki/Infrared_thermometer

Class MLX90614

Creates a MLX90614 object given an i2c bus object.

Example Usage:

# Take non-contact object and ambient temperature readings at intervals

import mlx90614
from machine import Pin, SoftI2C
from kooka import display
import time

i2c = SoftI2C(scl=Pin('P3A'), sda=Pin('P3B'), freq=100000) # set up the I2C interface
                                                           # note the clock frequency is <=100kHz
irt = mlx90614.MLX90614(i2c)                               # create the Infra-red thermometer object

while True:  # Loop runs forever
    display.fill(0)      # Clear the display
    display.print("IR Thermometer")
    display.print(irt.read_ambient_temp(), "C ambient")
    display.print(irt.read_object_temp(), "C object")
    if sensor.dual_zone:
        display.print(irt.object2_temp, "C Obj Zone 2")
    # Wait for 5 seconds
    time.sleep(5)

MLX90614 Constructor

class mlx90614.MLX90614(i2c, address=0x5A)

Creates the MLX90614 sensor object.

i2c should be a machine.SoftI2C object.

Note

The MLX90614 requires the I2C bus clock frequency to be 100kHz or less, so care must be taken to set the clock frequency when setting up the I2C bus object.

address defaults to 0x5A which is the only supported address.

MLX90614 Properties

property MLX90614.dual_zone: Is True is the sensor has dual-zone infra-red temperature sensing, else it is False.

property MLX90614.ambient_temp: Gives the ambient temperature of the sensor in degrees Celsius.

property MLX90614.object_temp: Gives the target object’s temperature in degrees Celsius.

property MLX90614.object2_temp

Gives the second zone object temperature in degrees Celsius if the sensor is capable of such a reading.

Otherwise a RuntimeError “Device only has one thermopile” is raised.

MLX90614 Methods

These methods are equivalent to the properties in the foregoing section.

MLX90614.read_ambient_temperature(): Returns the ambient temperature of the sensor in degrees Celsius.

MLX90614.read_object_temp(): Returns the target object’s temperature in degrees Celsius.

MLX90614.read_object2_temp()

Returns the second zone object temperature in degrees Celsius if the sensor is capable of such a reading.