STM32 6x5 led matrix pendant

Small pendant with embedded smt32 MCU, an 1s lipo charger, in order to display anything you want on your necklace, it consist of two pcb with a board to board 8 pin connector, on top of that your have to solder your battery, a LIR1140 for example, and a button if you want, then you program it by SWD and that it ! There is a free pad connected to PA5 if you want to add 1 channel adc capability, or lpuart RX capability, in order to for example add a station where you dock your pendant and you update the displayed char or text.