littleBits Tips & Tricks: The Sound Trigger Bit


This is the first in an on-going series of posts about littleBits. We encourage you to use the Tips & Tricks to enhance your Bit projects. littlebits is available in the Adafruit storeStarter Kit, Extended Kit and Teaser kit.

As you might have guessed, the sound trigger Bit responds to sound. That means, you can activate your circuit without even touching it. When you make a noise, the sound trigger sends an ON signal to the Bits that follow it.

Build the Circuit

Get started with your sound trigger Bit by building a simple circuit. Place the sound trigger between a blue power Bit and a green output Bit. We used a bargraph Bit to demonstrate our circuit. Once you have your circuit built….

Play With Sound

The Sound trigger responds to all sorts of sounds. Go ahead, try out different noises! Snap, clap, tap, stomp, blow on it, shake a maraca, ring a bell, make a sound, sing a song. The possibilities are endless. It’s also important to note that once you activate the sound trigger, the output will remain active for at least 3 seconds. This means that that your output will stay on for a little while even after you have stopped making sound.

Adjust the sensitivity

You can adjust the sound trigger to respond to different ranges of sound. Use the little purple screwdriver to do this. If you turn the screwdriver all the way to the right (+), you will make your sound sensor super sensitive. At this setting, the softest whisper will activate your circuit. The sound trigger will hear everything — your secrets are not safe! If you adjust the sensitivity all the way to the left (-), the sound sensor will not be very sensitive at all. Only super loud noises will activate your circuit now.

Infinite Loop

Use the sound trigger with the buzzer to make an infinite loop. In this circuit, when the sound trigger is activated and triggers the buzzer, it will remain on. This is beacause the buzzer is making a loud noise that in turn, keeps activating the sound trigger, thus creating an infinite loop.

No snooze Alarm (double alarm clock)

We have all done it – slept in way past the time we are supposed to wake up. This is not the right way to start the day. With this circuit, you will never sleep past your alarm again! This circuit sits at the foot of your bed and is activated by the sound of the sound of the alarm at your head. Even when you go to hit that snooze button on your phone, the “no snooze alarm” by your feet is buzzing on an infinite loop, thus requiring you to sit up and turn it off. Now that you are already up, you might as well stay up.

Do not disturb

When you are on the phone, you often don’t want to be disturbed. Some people don’t understand this, but this circuit will help to remind them. It is activated by the sound of your voice when you are talking on the phone and triggers a message on the exterior of you phone to keep these unwanted interruptions at bay.

Confetti Surprise

Try using the sound trigger, the fan, and confetti to throw the ultimate surprise party. Set up this circuit by the door of an unsuspecting friend. When they walk in the door, yell “surprise”. This will set off the sound trigger, and shower your friend with confetti.

Try bubbles instead of confetti

Drawing Machine

Make a drawing machine. This drawing machine draws for you when you only when you tell it to.

Throw a Dance Party

This circuit is activated by music! We taped characters to the dc motor and the fan, and let them do their thing in response to music positioned strategically near their sound triggers. We made sure to adjust the sound sensitivity so that they only dance in response to their respective music choices.

Rube Goldberg Kitchen Timer

Sometimes you just don’t hear the ding on your toaster or microwave, thus sacrificing that just warmed cup of hot cocoa or that perfectly toasted bagel. TO add incentive to eating hot food, we made an alarm that works double time. Not only does your toaster ding, but this project knocks cups onto the floor. You just can’t ignore that now can you. Circuit: power + sound trigger (set near “ding”) + wires + dc motor (with some sort of arm attachment). Don’t forget some plastic cups!

Run Horse Run (Cheer on your favorite Equine)

This is a really nice project that uses the sound trigger to make a moving image. See how to make it here.

littlebits is available in the Adafruit storeStarter Kit, Extended Kit and Teaser kit.

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