Full custom POS device with RFID, GSM, TouchGFX GUI, and 6-layer high-speed PCB.
A custom mobile payment terminal designed and built from scratch, covering PCB design, firmware, and UI. The device handles payment processing, RFID card reading, and GSM connectivity in a compact form factor.
6-layer high-speed PCB designed in Altium Designer. Stackup chosen to handle SDRAM and RGB LCD buses at speed while keeping EMI under control. RFID reader antenna integrated on-board. GSM antenna routed with care for coexistence with other RF paths.
TouchGFX used for the graphical user interface running on STM32F7. RGB LCD interface driven directly from the MCU. UI designed for fast transaction flow with minimal user input required.
FreeRTOS task architecture with separate tasks for payment processing, display, RFID, and GSM. C++ used throughout for the application layer. Bootloader implemented for field firmware updates over GSM.
SDRAM on a 6-layer board required careful signal integrity work. RGB LCD bus timing validated with oscilloscope. GSM and RFID coexistence validated through RF testing.