This week I finish up my Schematic and preparing the Bill Of Material (BOM) file for my PCB design.

I also study some Bluetooth module to be implemented onto my board. The most common bluetooth modules are ‘HC series’ (HC-05 and HC-06), with ’05’ able to be configured as Master or Slave while ’06’ is fixed. After spending some time studying these bluetooth modules, I learnt that there are many unused pins. Generally only 6pins (3.3, GND, TX, RX, KEY, LED) are used out of 26, so what happen to the other 20 so pins? Well…. almost all bluetooth module are made from the same company (the bluetooth chip) and the company that manufacture these modules actually provide flexibility to user to program the bluetooth via several methods, the common one is UART. Next would be the remaining PIO pins (Programmed Input/Output), I tried to gather more information regarding these pins but could not, therefore I could only assume some of these PIO pins are used to perform data transfer. *LEDs and KEY pins are connected to these PIO pins

This week I also compiled my BOM file. Sad to say generating this BOM file using KiCAD is not that straight forward. I initially taught by clicking ‘generate BOM file’ in KiCAD everything would lay out nicely, in fact many information are screen out. Therefore the only solution is to do it semi-auto, first to use KiCAD -> new PCB to generate a BOM file (.csv), then manually key in the more detailed information eg: description (capacitor voltage value), manufacturer, and part number if possible. However if KiCAD -> eeschema was used to generate the BOM file (.bom) the information from this particular folder is quite lacking, for it does not come with the footprints of components.

Of course there is another much ‘simpler’ method, which is to have key in or specified every details of component during schematic drawing, then generate BOM file. But since I did not actually done it in the beginning so had to do it semiautomatic.


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