light Sensing Buzzer

Always remember to unplug your Arduino from the power source before modifying your circuit...

Create the pictured circuit by adding the following items to your working potWithSound circuit:

• 2 x male/female wire connectors
• 3 x male/male wire connectors
• 1 x 10KΩ resistor
• 1 x photoresistor, aka LDR

Connect the female end of a male-female wire connector to each leg of your LDR. Plug both wires into the breadboard in 2 separate 5-hole sections as pictured (pink and brown wires). Your photoresistor will hang away from the breadboard.

Next, remove the wires connecting the buzzer from the breadboard and plug the buzzer wires directly to the Arduino Uno board (GND and pin 3). This will free up some male/male connectors.

Add in the resistor and extra wires as pictured.

Plug your Arduino back into power. If your buzzer was changing tone when the potentiometer was turned, it should still do so. Edit your code to use pin A4 for the sensor pin and upload the code. It should now change tone when the light received by the LDR changes. Hold your hand over the LDR to make it dark, shine a light (phone torch works well) on the LDR to increase light level.

You can adapt any circuit we have built by using the input from one circuit with the output from another. The device we have created is superbly annoying as it will never stop making noise.