Flying Stone Mini 55 implementation

Finally, we finished the design of FSM-55.

Its size is about 5cm x 5cm, with 5x5 LED matrix, 5 resistors and 5 capacitors.

When you pronounce it, please say, F-S-M "Go" "Go", since "Go" is the pronunciation of 5 in Japanese.

Components of FSM-55

  • MCU: STM32F030F4
  • Cell battery holder: BAT-HLD-001-THM
  • LED: LG R971-KN-1
  • Tactile switch: SKQGAFE010
  • 5 Resistors
  • 5 Capacitors


MCU is one of Cortex-M0 based ARM by STMicroelectronics. It runs at 48MHz and has 16KB flash ROM and 4KB RAM.


For battery holder, we choose BAT-HLD-001-THM.

LG R971-KN-1

For LED, we choose LG R971-KN-1.


For tactile switch, we choose SKQGAFE010.

Prototype of FSM-55

Since this prototype had an error, I put a jumper (black wire). You can see that this prototype has debug port connector (K3).

FSM-55 Prototype Front view FSM-55 Prototype Back view FSM-55 Prototype Side view

My plan is manufacturing a board with no battery holder or any connectors (but MCU, LEDs, Resistors, Capacitors, and Buttons) and ask users to put the battery holder (and possibly debug port connector, etc.).