Page 3 - Power Management

The Watch Base

The watch base (and what will eventually be attached to the strap) is composed of 3 main sections, the battery, the vibration alert, and the power switch / charging port.

To keep the design as simple as possible, the build combines a 2 position switch, a JST-PH connector, and a lipo battery to create a 2 state circuit. In one switch position, the lipo battery provides power to the watch. In the other switch position, the lipo battery is connected to the charging port. This means that the watch can EITHER be on OR in a charging enabled state. Allowing both charging and powering would require extra logic, and is a minimally needed feature. Since the watch can be powered while programming, you can test away without draining the battery.

The Power Schematic:


1.) insure the battery fits properly into the base

This is a good idea to verify our fit. If the battery cannot properly fit in the designed space, we may have to cleanup or redo our base print.

Battery placement


2.) Assemble the JST-PH connector / switch

Both the power / charging switch sit next to eachother. Gluing them together before assembly is required. After gluing, solder the charging port + to the left switch lead. Then, solder a micro wire lead to the opposite switch end (Leaving only the center with no connections yet)

Switch / Charge assembly


3.) glue switch / charging port module in place

this will secure your control logic into the base. You may need to trim some of the Base frame to properly fit your switch / charing port module.


Too much glue can seep into the switch mechanism and glue your switch in a certain direction! go easy!

Align it as flush as possible


4.) cut connection plug from battery and add a micro lead wire to ground end


Once you expose bare wires, do not let the two touch! They can damage / destroy your batteries, and lipos can catch fire!

Detail of the solder job


5.) solder battery ground / extra ground lead to battery charging port ground pin

Detail of the connection


6.) solder battery positive to middle switch pin

Once connected, this will enable the 2 position switch to direct the battery twards either the charging positive, or twards supplying power.

7.) test voltage / charging capabilities

Before you continue, make sure everything works! The switch position closest to the charging port is the off/charing mode. The opposite direction, the on mode. Most lipos I have ordered come somewhat chared, but you may need to charge yours a bit.

Testing Voltage


Testing Charge


8.) test spacing

Once you complete each major addition, it it's a good idea to make sure everything still fits together as it should. Waiting till the final assembly may create more of a headache to fix any sizing issues.

Power logic complete


Next Page - Vibration Motor

The Build