At the very beginning we wanted to see if it is possible and what it is like to be woken up by a vibration. In order to validate the idea, we used a Mi Band bracelet (activity tracker), whose vibrations can be triggered by the alarm. Team members have chosen me (Srdjan) as our test subject. 

As Mi Band bracelet successfully woke me up, we have tried the same with Kosta. Unfortunately as Kosta has deeper sleep (both as a child and as hearing loss person) vibration was not strong enough to wake him up few days in a row. 

We realized that Vibhear bracelet would need stronger vibration.

The first step was to chose the vibro motor. We found an adequate motor ROB-08449 on Spark Fun, however the delivery time to Serbia was too long so we looked for alternatives. We got an idea to use a vibro motor from an old Nokia phone. Through an NPN transistor we connected it to an Arduino Nano. Also an RTC module was added and using Arduino programmed to turn on the vibration every day at 6.30am. Everything was adequately packed and sent to Kosta`s parent for a test.

They set the alarm with confidence that the bracelet will wake him up right on time. Fortunately the vibrations proved to be strong enough to wake Kosta up 5 day in a row. This proved that the concept is valid and the next step is adding an audio module which will allow the future bracelet to respond to sound.