This is small laser cutter electronics board. The main goal of the development was to achieve a board width of less than 4 cm so that it could be easily mounted on standard 4020 profiles used in the construction of laser engravers. The board is designed for use with Fluid NC software.
The electronics are based on the ESP32 WROOM module, containing two TMC2130 SPI stepper motor drivers, a PWM output for the laser, and a Micro SD card slot. The initial programming of the ESP32 processor must be done via an external USB-UART converter; the board has a connector for this purpose. !!!Make sure that the converter supplies the board with 3.3V (and not 5V)!!! Further upgrades can be done using OTA.
The board also includes an Attiny 412 processor, which controls a WS2812 color status LED (internal with the option of connecting one additional external LED). This processor can be programmed via the UPDI interface (there is a connector on the board for this purpose), which is again connected to the USB-UART converter. You can find program for basic GRBL status messages parsing in FluidNC_Status repository. The Attiny 412 processor with status LED is an optional accessory; the board works even without it.
The schematic and PCB layout were created in KiCad 9. The Gerber and drilling files for PCB production are stored in the "Gerber" directory.