DoWatch DIY05

Add enough tin to the four pads of BEAD, as the picture shown above. When finished, remove the impurities on the surface of the tin, to eliminate bad contact.

Placing the steel ball on the hole in the center of the four tin balls, the steel ball should be supported by the four tin balls at a same time and not easy to move away.
The shake sensitivity of the DoWatch decreased when the tin balls get closer to each other, and vice versa.

Weld the boards A+B+C and the board D together, with the method presented above. In welding, please take a note to the positions of the fixed holes.

Then, weld the board E to the boards A+B+C+D with the same fixed holes. The board D and the board E should be welded separated, or else it may cause cold solder.

When finished, remove the impurities in the fixed holes on the board E, to make sure the fixed holes are flat.

Weld the rest components to the board F, as the picture shows. The 0 resistor is welded to 1N4001, and the 10uF capacitor to the position on the upper left side nearby 1N4001 (the 10uF capacitor is used to fix the magnet).

For the battery positive polarity, add a little tin to the middle 4 pads in the battery position, and add more tin to the outer 5 pads. (These 5 tin balls are used to fix the battery)

When finished, remove the impurities in the fixed holes on the board F.

The thin magnet is applied inside the DoWatch.
The internal magnet is very thin, which is easy to be damage and should avoid any collision. So when it is apart from the big magnet, please do not put them together any more.

Apply the double sided adhesive tape to cover the surface of the magnet for isolation and fixing, and place the magnet on the MCU.

Place the steel ball and the lithium battery to the corresponding positions.

Cover the areas of LOGO and the contacts on the back of the board F with the gummed paper to prevent from irreversible damage by tin.

Weld the boards A+B+C+D+E and the board F together, with the method presented above. Before welding the boards together, you should compress the battery on the lower right corner tightly to the board E, to ensure the battery is in good contact with the board.

Add enough tin to the four pads on the lugs of the board F to prevent the DoWatch short out when approaching to other metal.

When finished, check whether the tin is filling up the fixed. If not, please add more tin to the fixed hole.

Then, remove the tape and clean the impurities on the back of the board F.

Check whether the OLED screen is prefect matching the window of the board A. And clean the impurities on the surface of the board A.