ESP32 Forum

I’m building a digital thermometer using the MAX30205 body temperature sensor with Arduino Uno. The wiring is:

VCC → 3.3V

GND → GND

SDA → A4

SCL → A5

I used the example code from the library, but the readings seem stuck around 32–33 °C, even when I touch the sensor. I expected it to rise closer to body temperature (around 36–37 °C).

Has anyone worked with the MAX30205 before? Do I need extra calibration, or could this be an I2C address/wiring issue?

The MAX30205 senses temperature at its package . You must make good thermal contact (finger pad pressed on the IC or use small thermal pad/thermal paste). Wait 20–60 seconds for the sensor to come to body temperature; readings usually ramp slowly. Insulate the sensor from ambient air while testing. Wrap with a fingertip and a bit of tape or place it inside a small tube) so the body heat isn’t lost to the environment.