There are a lot of cats around where we live and some are agressive towards our pets. So here’s a description of a successful project to deter them from waiting outside our cat-flap to beat up our guys.
Auto Alarm Watch to remind kids about music lessons and the like. When in range of a suitable Raspberry Pi running the calendar connection software the watch gets new time alarm settings automatically via Bluetooth Low Energy (BLE). It then vibrates discretely when the time comes to leave for a music lesson. It is also a binary display watch.