adafruit_thermistor
¶
A thermistor is a resistor that varies with temperature. This driver takes the parameters of that resistor and its series resistor to determine the current temperature. To hook one up, connect an analog input pin to the connection between the resistor and the thermistor. Be careful to note if the thermistor is connected on the high side (from analog input up to high logic level/3.3 or 5 volts) or low side (from analog input down to ground). The initializer takes an optional high_side boolean that defaults to True and indicates if that the thermistor is connected on the high side vs. low side.
- Author(s): Scott Shawcroft
Implementation Notes¶
Hardware:
- Adafruit 10K Precision Epoxy Thermistor - 3950 NTC (Product ID: 372)
- Adafruit Circuit Playground Express (Product ID: 3333)
Software and Dependencies:
- Adafruit CircuitPython firmware: https://github.com/adafruit/circuitpython/releases
Notes:
- Check the datasheet of your thermistor for the values.
-
class
adafruit_thermistor.
Thermistor
(pin, series_resistor, nominal_resistance, nominal_temperature, b_coefficient, *, high_side=True)[source]¶ Parameters: - pin (Pin) – Analog pin used for the thermistor
- series_resistor (int) – resistance in series between you analog input and the thermistor, normally a 10K resistor is placed between VCC and the analog pin
- nominal_resistance (int) – nominal resistance of the thermistor. normally 10k
- b_coefficient (int) – thermistor’s B coefficient. Typically this is a value in the range of 3000-4000
- high_side (bool) – indicates if the thermistor is connected on the high side or
low side of the resistor. Defaults to
True
Quickstart: Importing and using the adafruit_thermistor library
Here is one way of importing the
Thermistor
class so you can use it with the namethermistor
. First you will need to import the libraries to use the sensorimport board import adafruit_thermistor
Once this is done you can define your
Thermistor
object and define your sensor objectthermistor = adafruit_thermistor.Thermistor(board.A0, 10000, 10000, 25, 3950)
Now you have access to the temperature with the
temperature
attribute. This temperature is in Celsius.temperature = thermistor.temperature
-
temperature
¶ The temperature of the thermistor in Celsius