2 - PCB assembly

[Tony]

Find the one marked '78l33', this is IC1. Note the flat edge faces UP:

[Tony]

The power supply socket, SK1:

[Tony]

Finally the USB socket SK2:

[Tony]

Now a few parts to fit on the other side. The LEDs don't have to be in this order but it will make the instructions easier to follow . The SHORT leg faces RIGHT for all four:

[Tony]

The switch SW1 can be fitted if you expect the clock will be often left unused and you don't want to remove the battery pack:

[Tony]

Time for the first power test. Connect the 15V power supply to SK1 and switch on. LED1 (red) should light - if not switch off and check your soldering.

If LED1 is lit, check the voltage across C6 - this should be 3.3V, then across C4 which should be 5V. If they're wrong or missing check around IC1,2 and D1,2,3.

If the voltages are correct we can fit the more expensive components next.

[Tony]

The SMD parts next, IC3: Note the dot faces to the top right.

[Tony]

IC4: Note the chamfered edge faces up.

[Tony]

Rx, a 750R resistor in bag1 but not pictured.



and finally Ry, a bodged-on 5k6 connected across IC4 (1k2 in the picture but it's a 5k6 now):

[Tony]

Finally the modules. Start with the Bluetooth module as it's the most difficult to solder into place. Note only the pads indicated need to be soldered: