Assembling "Main PCB": Electronics

Firstly you need to get OpenSimpleLidar PCB.
Gerber files for the PCB are placed here: /OpenSimpleLidar/tree/master/PCB
The easiest way to get PCB is to order PCB at some Chinese factory (JLCPCB for example).
Minimal price for several boards is $2 (without delivery price).

These are the main components which are required for PCB assembling: You need to assemble board using its schematic and BOM.

Photo of assembled board ("MainPCB_v1.0" version):
You should pay special attention to installing TSL1401 at the PCB. It must be carefully aligned in reference to special triangular marks at the PCB. Also don't forget about right orientation of the sensor:

You can test working of the MCU before installing the TSL1401 using this instruction: Link
You can test working of the sensor using instruction: Link