Steinhart-Hart Thermistor Calculator
Use this tool to:
- Calculate Coefficients: Convert three Resistance-Temperature data points into unique Steinhart-Hart constants.
- Generate Firmware Code: Instantly produce a ready-to-paste C function for microcontrollers like STM32, ESP32, or PIC.
- Verify ADC Accuracy: Map raw voltage readings to precise Celsius values to troubleshoot sensor noise or offset errors.
Key Input Parameters Explained
- Calibration Points (P1, P2, P3): These are three “snapshots” of your thermistor’s behavior. Each point requires a known temperature (e.g., from a reference thermometer) and the corresponding raw ADC value seen by your microcontroller. For best results, use a cup of Cold, Room temp, and Hot water to cover your full operating range when measuring.
- Pull-up Resistor (Omega): The fixed resistor used in your voltage divider circuit. Its precision is critical, as the calculator uses this value to “reverse-engineer” the thermistor’s resistance from the ADC counts.
- ADC Resolution: The bit-depth of your microcontroller’s Analog-to-Digital Converter (e.g., 10-bit for Arduino/1023, 12-bit for STM32/4095). This defines the scale used to translate raw voltage into digital data.
- Vcc Supply (V): Your system’s operating voltage, which serves as the reference for the thermistor’s voltage divider circuit.
Circuit & Calibration
Firmware Coefficients
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