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Grey Pill = simplified Black Pill compatible PCB for STM32G4xx

Pinout of the "Black Pill" module is very appropriate to be expanded by user specific circuits. Unfortunately it is not available with more attractive processors like ST32G4.
I bought a STM32G474 "Blue Pill" from China, but I got a very different unuseable board.
So I decided to build my own. With home-makers technology I could not integrate the USB connector, the reset button and BOOT0 button onboard. For this reason, I call my design "Grey Pill". From my point of view this is not a great disadvantage. It is not intended to be used as a standalone device and the onboad USB connector limits the freedom of design in a real working application. So, in paralled, a suitable support board was developed.

Grey Pill PCB photo
Grey Pill PCB, size = 55*20mm w.o. programmer pins

Reproduction of this board takes some skills and tools, so it is impossible to describe all details here.
The biggest problem is transfer of the PCB layout correctly on top and bottom layer of the photosensitive PCB. I get best results with an old HP P1006 laser printer and original HP toner on "Koch+Schröder Laserprint-Folie Typ8". Big black areas are over-painted at the film backside with a 0.6mm to 1mm fineliner pen. Exposure is made with a home-built UV fluorescent box.
Vias are drilled with 0.6mm and wired through-hole with 0.4mm tin-coated copper wire.

Grey Pill schematic photo

Grey Pill PCB layout

The subsequently downloadable material is copyrighted (c)2024 by Wolfgang Schemmert.
Assembly and use of the device is permitted for free by everybody for any purpose ("freeware")
All information is based on best knowledge, but without any warranty. Any responsibility is excluded.

Double layer PCB layout
(2:1 enlarged TIF format 300dpi. Transform into 600dpi but exactly keep the number of pixels).
Double layer PCB layout (1:1 TIF format 600dpi).
The layout is seen "through" the PCB from component side. Bottom layer is ok for PCB production. Top layer must be mirrored, as already performed at the leftmost picture.

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* State of information March 2024.
* Right of technical modifications reserved. Provided 'as is' - without any warranty. Any responsibility is excluded.
* This description is for information only. No product specifications are assured in juridical sense.
* Trademarks and product names cited in this text are property of their respective owners.