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The Build - 5 - Building the Back

The Completed Back with Battery, vibration motor, and charging port. logo

I strongly suggest placing the front and back plastic together, and using them to help glue in the screw nuts first. The motor needs some extra logic to drive it's amp requirments. Here is a great example of the simple circuit. When I set it up, I have the .1uF capacitor, diode, and 33 ohm resistor nestled with the motor, and have the transistor and 1K ohm resistor hidden underneath the front of the watch.

Detail of power / charging port logo

The wiring for power is fairly simple. Connect the Red battery wire (V+) to the middle of the switch. Connect the black (Ground) wire from the battery to the ground pin of the port for charging AND connect it to another wire lead (to be connected to the logic frame later) Now connect the switch pin next to the charging port to the voltage pin on the charger. And connect the other switch pin to a wire lead (to be connected to the logic frame later). In my build, I have a total of 4 wires on the back. 1 for power, 1 for ground, another to be connected to the transistor on the front, and another wire to be connected to the V Out pin of the voltage regulator.

Next Page - Building the front

The Build