A quick photo guide to take you through the soldering process, this one is pretty straight forward and simple, you should just not forget to configure the step down module at the right moment.
To start, make sure you have everything you need: the PCB and its component (see in hardware section), a soldering iron (any soldering iron with a thin tip, not too powerful either is better…), solder, a pair of tweezers, a sponge, a small screwdriver and a multimeter (or voltmeter) to configure the step down module .
Then solder the step down module to the PCB, that can be a little tricky and it’s not really done according to the book…. you have to solder from the side… that’s why a good amount of solder in the previous step is a good idea!
Now before soldering anything else, connect the board to the power supply through the DC JACK connector and configure the step down regulator to deliver 3,5V (should be 3,3V but 3,5V is still in the tolerance and 3,3V seems to sometimes be too weak). To do so, connect the power supply, and, using a multimeter (or voltmeter) to check the output of the step down, turn the small pot until the wished value is reached.
And solder it in place:
TX, RX and GND can be permanently connected but the GPIO0 pin should be connected to ground only when we want to reprogram the board. I use a free ground pin of my FTDI board to connect GPIO0 to ground when needed:
You can now check the Software section to flash your board, enjoy 😉