A proper smartwatch can cost quite a bit of money. However, there are some cheap Bluetooth-connected watches that offer basic functions like show your incoming calls, dial numbers and display the state of your phone battery. Not much, but these watches often sell for under $20, so you shouldn’t expect too much.
Because they’re so cheap, [Lee] bought one of these (a U8Plus) and within an hour he had the case opened up and his camera ready. As you might expect, the biggest piece within was the rechargeable battery. A MediaTek MT6261 system on a chip provides the smart part of the watch.