This schematic has not been officially tested. It follows best practices and should work, but please confirm your design before placing a large order!
PCBs have been ordered to confirm the design works as intended, this warning will be removed once the design is verified.
The primary goal of this project is to provide a semi-opinionated starting point for people new to STM32 microcontrollers. A majority of commonly used keyboard features are broken out on pins that are best suited for the purpose. (RGB on SPI, split on USART, etc)
A secondary goal of this project is to provide a schematic that allows for swapping between a number of readily available STM32 MCUs based on need and availability.
An example BOM is listed below, while a majority of parts are JLCPCB basic parts, the goal of this project is not to provide a cheap project, but a common project.
Components used are 0603 or larger as to make hand solderability as easy as possible for the designer.
The following non-standard libraries were used to design this project:
It is recommended to include these as global libraries in KiCAD, as they are very commonly used on most keyboard projects.
Designator | Description | Package | LCSC Part Number |
---|---|---|---|
Y1 | 8MHz | SMD-5032_2P | C115962 |
USB1 | HRO-TYPE-C-31-M-12 | HRO-TYPE-C-31-M-12 | C165948 |
U1 | STM32F072CBTx | LQFP-48_7x7mm_P0.5mm | C81720 |
U2 | SRV05-4 | SOT-23-6 | C85364 |
U3 | MCP1700T-3302E_SOT23 | SOT-23 | C39051 |
RESET1 | SW_Push | SMD-SW-4_5.1x5.1x1.5 | C318884 |
R_SHIELD1 | 1M | 0603 | C22935 |
R_RGB1,R_BOOT1 | 10k | 0603 | C25804 |
R_LDO2,R_LDO1 | 100k | 0603 | C25803 |
R_I2C2,R_I2C1 | 4.7k | 0603 | C23162 |
R_CC2,R_CC1 | 5.1k | 0603 | C23186 |
R_USB1 | 1.5k | 0603 | C328342 |
F1 | 500mA | 1206 | C151162 |
D_PWR1 | SMF9.0CA | SOD-123 | C123799 |
D_LDO1 | RB060MM-60TR | SOD-123 | C115330 |
D4,D3,D2,D1 | CD4148W | 0603 | C109002 |
C_XTAL2,C_XTAL1 | 30pF | 0603 | C22397 |
C_VDDIO2,C_VDD2,C_VDD1 | 100n | 0603 | C14663 |
C_VDDIO1,C_VDD3 | 4.7u | 0603 | C19666 |
C_VDDA2,C_LDO2,C_LDO1 | 1u | 0603 | C15849 |
C_VDDA1 | 10u | 0603 | C19702 |
C_SHIELD1 | 4.7n | 0603 | C53987 |
BOOT1 | SW_SPDT | SW_SPDT_PCM12 | C221841 |
This project is licensed under the Unlicense. Please see LICENSE for more information.