This project is about an OLED Wrist watch built around 16-bit controller known by the name MSP430 and is manufactured by Texas Instruments. These controllers are designed specifically for low-power or battery powered operations and seems to be a perfect choice for a wrist watch. It runs on a cr2016 based coin cell and an OLED display. This project is actually an update to the older edition since the author wanted to enhance its battery life. Earlier it used to consume around 3ma of current but now it’s capable of consuming current in micro amperes with a good OLED display.
The watch also has an on-board accelerometer in the design, which is used to detect tap and double tap so that it can wake up the controller using interrupts. The accelerometer has a shared SPI bus with the display. Also an under-voltage circuit has also been placed so that it can be used with an unprotected LiPo. The controller used is MSP430FR5738 which is a part of the MSP430 family and consume a way less current. Another advantage is that it has a Ferroelectric RAM which is also capable of zero-power data retention.