Keyboard for Seiko UC-2000

Experimental application for Android. Phone speaker is used as an Induction coil to transmit data to the watch. Unfortunately, this does not good work on all phones, I tested app on Nexus 5X (on video) - very good (only 10-20% of errors), Galaxy S8 - medium (with good positioning - 30-50% error), Nexus 5 - medium (with "antiphase" options).. With a very poor connection, you can try to remove the back cover from the watch. Please comment, on what devices you were able (or failed) to transfer data to the watch. If you need an emulator for the watch itself, see https://github.com/azya52/Emulator2000