Playground Temperature

But wait! There's more -- the Circuit Playground Express can also tell the temperature!

How, you ask? With a build in thermistor. This little sensor is a thermally sensitive resistor, meaning it's resistance changes based on temperature.

We can access its readings in CircuitPython by importing the adafruit_thermistor library, and then using the board.TEMPERATURE pin to read the thermistor value.

Copy the code below in to a new file, then save it onto the board as Then, open up a REPL session and you'll see the temperature readings in both Celsius and Fahrenheit. 

# CircuitPlaygroundExpress_Temperature
# reads the on-board temperature sensor and prints the value

import time

import adafruit_thermistor
import board

thermistor = adafruit_thermistor.Thermistor(
    board.TEMPERATURE, 10000, 10000, 25, 3950)

while True:
    temp_c = thermistor.temperature
    temp_f = thermistor.temperature * 9 / 5 + 32
    print("Temperature is: %f C and %f F" % (temp_c, temp_f))


Try placing your finger over the sensor (you'll see a thermometer icon on the board) and watch the readings change.

Last updated on Apr 24, 2018 Published on Oct 12, 2017