# Basic concepts: * ValueMutex * PubSub, Publisher, Subscriber * ValueManager * LayeredReducer # HAL We use [Zephyr HAL](https://docs.zephyrproject.org/latest/reference/peripherals/index.html). # OS We use [CMSIS OS v2](https://www.keil.com/pack/doc/CMSIS_Dev/RTOS2/html/group__CMSIS__RTOS.html) for thread management and IPC. # UI * **[Input](https://github.com/Flipper-Zero/flipperzero-firmware-community/wiki/API:Input)** * **[Display](https://github.com/Flipper-Zero/flipperzero-firmware-community/wiki/API:Display)** * **[LED](https://github.com/Flipper-Zero/flipperzero-firmware-community/wiki/API:LED)** * **vibro** * **[Sound](https://github.com/Flipper-Zero/flipperzero-firmware-community/wiki/API:Sound)** * **backlight** # System ## batt voltage ## batt charge # CC1101 ## SPI ## IRQ # SD Card ## SPI # NFC ## SPI ## IRQ # IR ## TX LED ## RX ADC # RFID 125 kHz ## Carrier ## Pull ## Comparator RX (shared with touch key) # Touch key ## Pull ## Comparator RX (shared with RFID 125 kHz) # External GPIO # External SPI # External I2C # UART # USB # BLE