Flex sensor 2.2" (bend resistor) with ESP32

Supply 3.3 V Bus ANALOG Measures bend

Pins and ESP32 wiring

Pin	Role	ESP32 pin	Notes
1	Power	3V3	One leg to 3V3
2	Analog output	D34	Other leg to an ADC pin and through about 47 kΩ to GND. To an ADC pin (prefer ADC1: GPIO 32 to 39)

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

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

void loop() {
  int mv = analogReadMilliVolts(34);  // 2 on GPIO 34
  Serial.println(mv);
  delay(200);
}

Spectra Symbol Flex Sensor datasheet, Flat resistance about 25 kΩ ±30%; resistance rises when bent

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