DoWatch DIY04

Joint the board A and the board B together, to make the pressure keys.

Add some tin to the pads on the corners of the board A, to avoid cold solder.

Please take a note to the direction symbols on the boards.

Compress the PCBs together with two clamps.

Add enough tin to the four fixed holes on the board B, and shift the welding header inside the fixex holes until the tin added on the pads of the board A have been melted down.
In welding, the bubbles in the fixed holes may make you believe that the tin is enough, but it is cold solder in actual. So please add more tin to the pads to remove the bubbles.

The tin should fill up the fixed holes. If not, you should add more tin to the fixed hole.

Put one of the probes of the universal meter to the common end of the DoWatch and the other probe to another end of the DoWatch. Then, press the pressure key. If the universal meter shows the circuit is on when pressing the key, and off when releasing the key, it means the keys installation is successful.

Remove the protective film from OLED. Don’t apply any protective film to OLED, since it may cause the key difficult to be pressed down.

Put the boards A+B on the board C to find out the proper fixing position for OLED.

Stick the OLED to the proper position on the board C with the double-sided adhesive tape.

Finally, compress the OLED screen across the board A.

Weld the boards A+B and the board C together, with the method presented above.

When finished, clean the fixed holes on the board C with alcohol or fresh cloth, to make sure the fixed holes are flat.