NTC 10 kΩ temperature probe (with divider) with ESP32

Supply 3.3-5 V Bus ANALOG Measures temperature

Pins and ESP32 wiring

Pin	Role	ESP32 pin	Notes
OUT	Analog output	D34	Middle of the divider: NTC to 3.3 V, 10 kΩ to GND. To an ADC pin (ADC1 on ESP32). The voltage rises as it gets warmer
VCC	Power	3V3	Use 3V3 so the output stays in the ADC range
GND	Ground	GND

Suggested wiring for the 30-pin ESP32 DevKit, avoiding flash, input-only and strapping pins. BoardPilot checks it for you as you wire.

An NTC is not linear: convert with the Beta formula (B25/85 = 3977 K for this type) or a table, not a straight line. (Vishay NTCLE100E3 datasheet, R25 = 10 kΩ, B25/85 = 3977 K, resistance/temperature table)

void setup() { Serial.begin(115200); }

void loop() {
  int mv = analogReadMilliVolts(34);  // OUT on GPIO 34
  Serial.println(mv);
  delay(200);
}

Vishay NTCLE100E3 datasheet, R25 = 10 kΩ ± 5 %, B25/85 = 3977 K, operating range -40 to +125 °C

Part data: CC BY 4.0, free to reuse with credit to BoardPilot.