> For the complete documentation index, see [llms.txt](https://docs.blynk.io/en/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.blynk.io/en/blynk-library-firmware-api.md).

# Blynk Library - firmware API

- [Installation](https://docs.blynk.io/en/blynk-library-firmware-api/installation.md): How to install Blynk library on popular IDEs
- [Install Blynk Library in Arduino IDE](https://docs.blynk.io/en/blynk-library-firmware-api/installation/install-blynk-library-in-arduino-ide.md): Step by step guide on how to install Blynk Library
- [Install Blynk Library for Platformio.org](https://docs.blynk.io/en/blynk-library-firmware-api/installation/install-blynk-library-for-platformio.org.md)
- [Install ESP8266 core for Arduino IDE](https://docs.blynk.io/en/blynk-library-firmware-api/installation/install-esp8266-core-for-arduino-ide.md)
- [Configuration](https://docs.blynk.io/en/blynk-library-firmware-api/configuration.md)
- [Connection Management](https://docs.blynk.io/en/blynk-library-firmware-api/connection-management.md)
- [Device Online/Offline Status](https://docs.blynk.io/en/blynk-library-firmware-api/devices-online-status.md)
- [Digital/Analog Pins](https://docs.blynk.io/en/blynk-library-firmware-api/digital-analog-pins.md)
- [Virtual Pins](https://docs.blynk.io/en/blynk-library-firmware-api/virtual-pins.md): Send and receive data from device
- [Widget Properties](https://docs.blynk.io/en/blynk-library-firmware-api/widget-properties.md): The widget property is a widget attribute like color, labels, min/max, ..., and others that could be dynamically changed from the hardware or HTTPS API.
- [State Syncing](https://docs.blynk.io/en/blynk-library-firmware-api/state-syncing.md): A feature in the Blynk library firmware API that allows the hardware device and the Blynk server and apps to keep track of the same state.
- [Timers](https://docs.blynk.io/en/blynk-library-firmware-api/blynk-timer.md): How to use timers in code
- [Time (RTC clock)](https://docs.blynk.io/en/blynk-library-firmware-api/rtc-clock.md): Working with time using Blynk API
- [Timezone / Location](https://docs.blynk.io/en/blynk-library-firmware-api/timezone-location.md)
- [Log Event](https://docs.blynk.io/en/blynk-library-firmware-api/log-event.md): How to log an event using firmware API
- [Metadata](https://docs.blynk.io/en/blynk-library-firmware-api/metadata.md): Set and receive metadata values
- [Debug](https://docs.blynk.io/en/blynk-library-firmware-api/debug.md)
- [Reboot](https://docs.blynk.io/en/blynk-library-firmware-api/reboot.md)
- [Over-The-Air Firmware Updates (OTA)](https://docs.blynk.io/en/blynk-library-firmware-api/ota-updates.md)
- [Other](https://docs.blynk.io/en/blynk-library-firmware-api/other.md)
- [Limitations and Recommendations](https://docs.blynk.io/en/blynk-library-firmware-api/limitations-and-recommendations.md)
- [Blynk Protocol](https://docs.blynk.io/en/blynk-library-firmware-api/blynk-protocol.md)


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