Singing Arduino Nutcracker

This nutcracker opens its mouth based on the input audio. It can easily be done in under 3 hours for a begginer to go from a pile of parts to a singing nutcracker.

For this project, you're going to need a Nutcracker with a movable mouth, a prototype board, some wires, a 3.5 mm jack, a 3.5 mm audio cable, two 1k Ω resistors, a servo, and an Arduino Uno.

Step 1: Solder the 3.5mm Audio Jack to the Perfboard

Solder the 3.5mm audio jack on the edge of the perf board. On the left and right pins solder 1k Ω resistors like on the pictures.

Step 2: Prepare the Audio Cable

I am using an audio cable but you can also use a wire terminal or another audio jack or something else.

If you are using an audio cable just tin the wires.

Step 3: Solder the Cable to the Jack

So we are soldering this so you will still have and audio output. Solder the left channel of the audio cable to the left channel of the jack, the right channel to the right channel of the audio jack and ground to ground.

Bridge together the ends of the resistors and connect a black wire to the bridge. (As shown in the picture)

Step 4: Almost Done!

Solder a red wire to the left or the right channel. (like in the picture)

Step 5: Connecting Wires to the Arduino

Solder the red wire to pin A1 of the Arduino and the black wire to ground.

Attach the servo positive wire to 5v, negative to ground and the signal wire to pin 9.

Step 6: The Code

Link to the code https://pastebin.com/xMCfrmtW

Upload the code to the Arduino. In the code, you can find comments that explain what does what. You will probably need to change some variables like sensitivity.

Step 7: Attaching the Servo

Hot glue the servo in between the nutcracker's legs and connect the servo with the arm on the back of the nutcracker. I used thin wire and connected one site to the servo and for the other side, I drilled a small hole in the lever thingy that moves the mouth.

Step 8: Setup

Plug the 3.5mm audio cable to the audio source, and plug your speakers or similar to the 3.5mm audio jack and enjoy your creation.