The LM35 temperature sensor and red led are powered with 5V from the Arduino board. How does the circuit works? As you can see in the sketch on the first line I included the LiquidCrystal library ...

Now you can build your own room temperature monitor using an Arduino board. The circuit is a combination of an Arduino UNO board, LM35 temperature sensor, ...

In this case, the temperature is read by a LM35 temperature sensor and that value, along with the time, is recorded to a .csv file on the SD card in one minute intervals.

Measuring temperature turns out to be a fundamental function for a huge number of devices. You furnace’s programmable thermostat and digital clocks are obvious examples. If you just needed to… ...