We started this hackathon with no real idea for a project, and the intention to build something random and have fun. Then the pieces started coming together. The conversation went something like:

“What should we build?”

“I dunno, what’s something that’s annoying every day?”

“When people try to talk to me.”

“We could make a device that calls your phone so you can get out of a conversation!”

The idea developed from there, being broadened to a general purpose bluetooth alert system. We even added a chatbot you can talk to on the phone!

What it does

Redtooth gets you out of sticky situations. It is a mobile app and a Bluetooth-enabled device wearable around your neck. You can configure it to send you phone calls or text messages that excuse you when you need to be excused, or you can configure it to call or text people you trust when you don't trust your surroundings. Customize the name you receive a call from, write the perfect message that removes you, or even have a chat with Redtooth's charismatic chat bot, CARL (Chatbot with Automatic and Rapid Learning). Reach back to press the button behind your neck in your time of need, and Redtooth will assist you.

How we built it

The wearable bluetooth necklace uses an Arduino microcontroller, a bluetooth module, and two coin cell batteries. Two wires form the module wrap around the back of the neck to a button that the wearer can press.

The chatbot works by making links between phrases it is given. Then it looks up whatever you say in its database and says a phrase that is linked to it. Because of this setup, it automatically learns and chats at the same time.

Our website at uses for the domain name, AWS for the hosting, and Wordpress to hold our pages. The chatbot is hosted separately so it doesn't expire with the domain.

Challenges we ran into

When making the necklace, we had to go back in and add another battery since one battery's voltage would quickly decrease below the minimum of the bluetooth chip. The device was being discovered in the phone's bluetooth menu, but not the app. We had to downgrade the bluetooth libraries and switch to Android only since the chip was bluetooth 2.0. Getting the website running was a challenge because we were trying to cobble together a domain from with an AWS server and also run the chatbot. We ended up calling customer service for and they were able to help us. The chatbot is hosted on a team member's personal website so it will stay up even when the AWS subscription expires. After working smoothly for a while, the text-to-speech engine started reading the wrong page from the server! It turned out that a rogue search and replace had changed the URL.

Accomplishments that we're proud of

Getting the bluetooth to show up on the phone was a big milestone. The moment when we said "Hello" into the phone and CARL talked back to us was amazing! Also being able to nonchalantly press a button and have your phone ring is so fun!

What we learned

  • how voice-to-text apis were typically structured and used
  • how bluetooth protocols differ in detection and strength
  • how calls are usually routed through android's OS

What's next for redtooth

We plan to add support for iOS, options to edit the ringtone and phone numbers, and support for plugins so anyone can write code to be run when the button is pressed. It could eventually be turned into a product that would help people send an emergency alert or run an app without drawing attention to themselves.

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