Code for a portable temperature sensor using a Raspberry Pi Pico and BME280 sensor
Relies on using the Pimoroni firmware - see here: https://learn.pimoroni.com/article/getting-started-with-pico Using the BME280 breakout (https://shop.pimoroni.com/products/bme280-breakout) from Pimoroni as well as their Pico Display pack (https://shop.pimoroni.com/products/pico-display-pack).
You will need to install MicroPython umqtt.simple for the Adafruit IO MQTT publishing functionality.
This goes with the blog post here: https://www.recantha.co.uk/blog/?p=21637