Urgent Light
From: https://create.arduino.cc/editor/s09097/88945d49-f843-49b3-af38-803ff904df62/preview
An urgent light is used when there's no light
Things you will need:
Arduino
Computer
LED
Photoresistor
Resistors
Step 1: Wire Up LED's
First, take 6 LED's out. I chose 2 green, 3 yellow and 1 red. You can change it if you like. Add a wire between the negative rail of the breadboard and the GND pin of the Arduino. Then plug the short leg of the LED into the negative rail of the breadboard. Then we need 6 resistors.
Coding Part
This is the code: https://create.arduino.cc/editor/s09097/88945d49-f843-49b3-af38-803ff904df62/preview