Wearable smart metronome powered by haptic motor

thingiverse

This is an early-stage proof of concept. ## Introduction The goal is to create a smart, open-source metronome driven by a vibration motor, similar to the commercial product Pulse. This project utilizes a low-energy Bluetooth module connected to a vibration motor. It also uses a rechargeable 150mah lipo battery. The case employs a thread-based system to avoid using screws. ## Usage The board receives a BPM value from Bluetooth and runs the motor in a loop, converting the value sent by the user to milliseconds (60000/BPM=ms). If the value is set to 0, the loop stops. The initial value is 0. The motor runs for 150ms per pulse, generating a good vibration. To connect with the board and send commands, I'm using the app Lightblue, which is compatible with mobile and desktop platforms. ## Current Parts List RedBear BLE Nano Bluetooth module Micro Vibration Motor 3.7V 150mAh Lipo Battery USB charger Transistor A bracelet or a similar item to hold the metronome - A generic rubber bracelet works fine but you can use anything else. ## Results I successfully played drums using the metronome, and it worked well. The vibration level is sufficient, and I'm happy with this first iteration and proof of concept. However, I'm not sure how long the battery will last as I haven't used it for extended periods yet (will report back once I know). The Bluetooth module is very efficient but I'm unsure about the vibration motor's power consumption. I should work on detailed schematics if this project evolves. If you want to build it now, here is a generic instruction on how to connect a motor to an Arduino. ## Code The current code for the Bluetooth module can be found here. ## Next Steps These are my next steps: - Find a bracelet that's easily purchasable. - Provide detailed schematics. - Add more features to the metronome (ex: different time signatures). - Develop a mobile app to manage the metronome and avoid using a generic app. - Improve cable/wire management for a smaller form factor. - Include a power switch.