You are here

Display Temperature using a Seven Segment LED, an Arduino and a DHT11 Temperature Sensor

In this project, I'd like to learn about Arduino and in order to do that I'll be building a project that controls an aircon. My bills on electrocity is quite high since I'm using an aircon 16-20 hours a day so I'm thinking maybe I could lower that effeciently controlling the temperature and setting schedules on when should it turn on.

For the first step, I'd just like to display the current room temperature. In order to do that I'm using a DHT11 Temperature & Humidity Sensor and display the read temperature to a 7-Segment Display (I'll be using 2 digits for the mean time. You can view a video of this project at .


How it works

The temperature gets read by DHT11 sensor and is passed to pin 2 of the Arduino. Arduino processes the temperature data and trigger LED pins at 3, 4, 7, 6, 5, 10 and 8 (a, b, c, d, e, f, g) to display the temperature. Digits of the 7-Segment display are controlled by pins 12 and 11 (ones and tenths respectively) through a switching transistors (BC55).

Source code

The source code is availabe for download on Github ( Please note that I'm not using the Arduino IDE for compiling and uploading the code. Instead, I'm using PlatformIO IDE for syntax highlighting and to manage a custom library within this project.

Romualdo Dasig's picture