ESP32 - LM35 Temperature Sensor
This tutorial instructs you how to use ESP32 to read temperature value from LM35 temperature sensor, and print it to Serial Monitor.
Hardware Used In This Tutorial
1 | × | ESP-WROOM-32 Dev Module | |
1 | × | Micro USB Cable | |
1 | × | LM35 Temperature Sensor | |
1 | × | (Optional) 5V Power Adapter | |
1 | × | (Optional) DC Power Jack | |
1 | × | (Optional) ESP32 Screw Terminal Adapter |
Introduction to LM35 Temperature Sensor
LM35 Temperature Sensor Pinout
LM35 temperature sensor has three pins:
- VCC pin: connect this pin to VCC (5V)
- GND pin: connect this pin to GND (0V)
- OUT pin: This pin outputs voltage in proportion to the temperature value.

How LM35 Temperature Sensor Works
The LM35 sensor outputs the voltage in linearly proportion to the Celsius temperature. The output scale factor of the LM35 is 10 mV/°C. By measuring the voltage on the LM32's OUT pin, we can calculate the temperature value.
Wiring Diagram between LM35 Temperature Sensor and ESP32
The wiring diagram with power supply from USB cable

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The wiring diagram with power supply from 5v adapter

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ESP32 Code
Quick Instructions
- If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE.
- Copy the above code and paste it to Arduino IDE.
- Compile and upload code to ESP32 board by clicking Upload button on Arduino IDE
- Make the sensor colder or hotter. For example, putting the sensor near an ice cup
- See the result on Serial Monitor. It looks like the below:
Video Tutorial
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