DoWatch DIY07

There are 4 pieces of PCBs for the charger: the board G, the boards H+I, and the board J.

Firstly, install the components to the board G

Add some tin to one of the pads corresponding to each component, making it easier to fix the component to the board in welding.

Weld the capacitors and resistors to the board. If a 10K (103) resistor is welded on the R-X, the charger is set on normal charging mode. If a 1K (102) resistor is welded on the R-X, the charger is set on fast charging mode.

Weld the charger control IC to the board. In welding, please take a note to the position of the Pin 1 of the IC.

Weld the rest pins of the components to the pads on the board carefully.

Upside down the LED indicator, and weld it to the LED position.

There are 5 reserved interfaces for custom development. They can sever as ISP interfaces or external charging/discharging interface.

Weld the MicroUSB interface. You only need to weld the outer two pins of 5PIN.

There are 4 groups of contacts located on each corner of the board G. Add some tin to the middle contact of the upper left contact group and make the contact raised. And the same operation should be applied to the upper right contact group and lower right contact group too.
For custom serial communication development or ISP operation, you should add some tin to the pad in the center of the lower left contact group. However, it is recommended to remain the contacts in flat, since the four raised contacts in a different level may have impact on charging.

When finished, connect the board to the power supply via a USB cable, and check whether the LED indicator is on, and whether the charger control IC is overheat.

Add some tin to the fixed holes of the board G, with the same method applied to the board A.

In welding the broads H+I, you should weld the board H to the board G firstly, and then weld the board I to the board H, to avoid cold solder.

Before installing the magnet, you should find out the opposite pole of the magnet to the internal magnet.

Cover the magnet with the double-sided adhesive tape, and put the magnet on the board G. The magnet pole opposite to the internal magnet should be put towards the board.

Weld the boards G+H+I and the board J together, with the method presented at DoWatch making.

Remove the impurities and plug the USB cable to the charger.

The correct steps for DoWatch charging are: attach the DoWatch to the charger, and then connect the charger to the power supply via a USB cable. Then, the OLED of the DoWatch will show the battery charging icon.

It may take 2~3 hours to charge the DoWatch. And the battery icon will remain on the OLED screen even the charging is finished, as long as the DoWatch is attaching to the charger. When the charging is finished, remove the DoWatch from the charger.