Since childhood, I always wanted to try my hands on electronics. Recently I bought the Arduino and started exploring it. In this process, I got to know more about Light Dependent Resistors (LDR).
Somehow, I stumble across this idea. Basically, it’s an electric sunflower which does the opposite of actual sunflower. It points to the darkness!!!
Step 1: Stuff You Need
- 3 LDRs
- 3 10k Ohm resistors
- A servo motor
- Arduino Board
- Few Jumper wires
- Soldering Kit
- Perforated PCB
- Small Pot along with some dry soil.
Step 2: The Circuit
The crux is each LDR is responsible for an angle, left for 180 degrees, middle one for 90 degrees and right one for 0 degrees. For example, if the middle LDR not receiving any light and other LDRs are getting some light then
Arduino will receive following input:
- Left LDR => HIGH
- Middle LDR => LOW
- Right LDR => HIGH
Based on this input, Arduino can compute the angle (90 degrees in this case) and send this information to the servo motor.
Step 3: The Code
In layman terms, that’s what the code does:
- It takes input from 3 LDRs.
- Using this input, it calculates the amount of light each LDR is getting.
- Now, it computes the angle it should go. For example if the right & middle LDR both are not getting any light, then the angle calculated will be 45 degrees (Mid angle of 0 degree & 90 degree is 45 degrees).
Find the code here.
Step 4: Build the Circuit
Use Perforated PCB to solder resistor and LDRs. Use the Arduino breadboard for connecting PCB and servo motor. Upload the code and test.
Step 5: Plant the Anti-sunflower
I’ve used a small pot and made a hole in it to pass the wires. Put some soil, keep the servo motor, add some more soil. Then just connect the servo motor with Arduino and you’re done!