Engineering, Gardening

Backyard Gardening #7: Light Sensor | #DIY and #Arduino

Introduction

Previously, the smart gardening device was built as an alternative method to the analog three-way meter (amazon link) shown in the picture below.

Programming

Using Arduino Software on Windows OS.

The arduino module used in this project is Arduino Micro (Amazon Link).

The data of light sensor output to Arduino are voltage values. In general, when it is brighter, the resistance value of the light sensor becomes smaller. As an example, about 100 Ohm in the sun light and ~ 10M Ohm in darkness.

Arduino microcontroller is programmed so that the log from Arduino produces the voltage value at a node of the light sensor every second. This indicates the brightness captured by the sensor. The data will be shown on the Arduino console and 4-line LCD.

Testing

With LED Desk Lamp, Arduino and Light Sensor (Amazon Link).

LED Desk Lamp has 4 light brightness levels

Video

As the desk lamp gets brighter, the voltage value goes down. This means that the resistance of the light sensor goes down.

Next

Test this prototype outside and compare the results with the analog meter.