https://github.com/Trexation/micropython-generic-thermistor

Micropython Generic Thermistor Library is a basic software module designed to simplify temperature sensing using NTC thermistors within MicroPython-based projects. The library assumes a generic NTC thermistor on the ground side of a voltage divider.
https://github.com/Trexation/micropython-generic-thermistor

Last synced: about 2 months ago
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Micropython Generic Thermistor Library is a basic software module designed to simplify temperature sensing using NTC thermistors within MicroPython-based projects. The library assumes a generic NTC thermistor on the ground side of a voltage divider.

• Host: GitHub
• URL: https://github.com/Trexation/micropython-generic-thermistor
• Owner: Trexation
• License: mit
• Created: 2024-02-04T00:42:50.000Z (11 months ago)
• Default Branch: main
• Last Pushed: 2024-02-04T02:07:47.000Z (11 months ago)
• Last Synced: 2024-08-04T00:07:23.398Z (5 months ago)
• Language: Python
• Homepage:
• Size: 40 KB
• Stars: 2
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-micropython - micropython-generic-thermistor - MicroPython Generic Thermistor Library for simplified temperature sensing using NTC thermistors with voltage dividers. (Libraries / Sensors)

README

        
# Micropython Generic Thermistor Library

Micropython Generic Thermistor Library is a basic software module designed to simplify temperature sensing using NTC thermistors within MicroPython-based projects. The library assumes a generic NTC thermistor on the ground side of a voltage divider. It provides functions for converting raw analog sensor readings into temperature values, taking into account the non-linear nature of thermistors using the β parameter equation.

## Features

- Temperature output in Kelvin, Celsius, or Fahrenheit

- Checks for thermistor shorts to VCC or GND

- Checks for reasonable output values as specified in Constants

- New thermistors only require one line of code!

## Installation - Hardware

Figure 1 demonstrates the expected wiring scheme. 

R1 and the thermistor cannot be swapped with this library; 

the code assumes the thermistor is on the ground side of the voltage divider.

![Figure 1 - Wiring Diagram](images/schematic.png)

Notes:

- The resistance of R1 should be similar to the nominal resistance of the thermistor

- Thermistor nominal resistance and beta values can be found on the thermistor datasheet

- Thermistor is assumed to be NTC

## Installation - Software

1. Have a Micropython environment set up on something; for example, an ESP32

2. Upload the thermistor.py file onto the Micropython device; upload steps vary based on familiarity with the terminal, OS, and/or IDE. You can create a new file named thermistor.py on the embedded device and copy-paste the code into the file.

3. Configure the object constructor "Thermistor" with your values. The below example uses pin 4 on an ESP32 with a 10k ohm NTC, beta=3435, thermistor, and 10k ohm voltage divider. Make sure you use your own values here!

```python

therm = Thermistor(ADC(4, atten=ADC.ATTN_11DB), beta=3435, therm_ohm=10_000, divider_ohm=10_000)

```

4. See the example main.py file

## Warnings

- This code was only tested on a single ESP32, with a single version of Micropython. Your mileage may vary.

- This code does not have thermal runaway protection; use heating devices at your own risk.