The Idea
A while back I wanted something that made a noise to notify me of an event. The original plan was to replicate Andy Rubin’s gong doorbell. The large gong and mallet was a little bit out of my price range but a good idea is a good idea. I ordered one from Amazon and combined with a servo and a Arduino Nano clone I set about the same idea.
Gong
With a little bit of tape it was finished. The design is basic but functional. The beater is attached to a 9g servo which acts as the human arm. An Arduino Nano clone is used to to move the servo.
In action:
https://www.youtube.com/watch?v=-vFhrOvHxIs
Triggering the Gong
Communication to the gong is done over serial. Sending “gong\n” over serial, triggers the beater/mallet to strike the gong and then move out the way to avoid a second gong strike. The code for the Arduino is below:
Conclusion
For a mini project this is perfect for getting servos and Arduinos to work together. Mine is currently connected to my Google calendar to alert me five minutes before a meeting.
The door bell will have to wait.