MLX90614 contactless temperature sensor
In case somebody can be interested (I've not seen any old posts talking about it), I've just tested this contactless temperature sensor from aliexpress (https://www.aliexpress.com/item/Free-Shipping-GY-906-MLX90614ESF-New-MLX90614-Contactless-Temperature-Sensor-Module-For-Arduino-Compatible/32465332978.html?spm=2114.13010608.0.0.gJhz6T) which is pretty cool.
It reports BOTH the ambient temperature and the object temperature (the latter ranging from -70 to +380 C), has a standard i2c interface and works great with this library: https://github.com/adafruit/Adafruit-MLX90614-Library.
The price is also pretty interesting, being around 3.5$.
It can be used in many applications to e.g. measure the temperature of a body, the temperature of an oven, the temperature of a board, or whatever object could make sense in your project.
@user2684 What's your experience on the measurement distance?
Posts on the internet suggest it is only a few cm's without using a lense, which would make practical use very limited IMHO.
It starts "sensing" e.g. the human body when around 50cm away but the real measurement happens only when less than 10 cm away. Agree this is not the best scenario but could be still probably useful for something line on-demand body temperature measurement or when the absolute value has a relative importance (e.g. when a significant variation has to be detected).