# [Basic concepts](Basic-API)

* ValueMutex
* PubSub
* ValueManager
* ValueComposer

# [HAL and devices](HAL-API)

* GPIO
* PWM
* ADC
* I2C

* IR RX (unimplemented)
* Comparator RX (touch key and RFID 125 kHz RX) (unimplemented)

# [SPI Devices](SPI-Devices-API.md)

* Sub-GHz chip
* NFC
* SD card
* display
* external SPI

# 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](Input-API)**

* **[Display](Display-API)**

* **[LED](LED-API)**

* **[Backlight](Backlight-API)** (unimplemented)

# [Power](Power-API)

* batt voltage
* batt charge

# [UART](Serial-API)

# USB

# BLE