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Espressif Family
Arduino, along with a vast amount of peripheral boards, lacks integration of the networking capabilities in one SoC. Espressif ESP series was the natural answer for this disadvantage as their ESP 8266 with integrated WiFi, introduced in 2014, is widely recognised as a turning point for the IoT market, delivering de-facto fully functional IoT chip, providing high performance and low power to the end users and developers. ESP 32 launched in 2016 brought even more disrupting effect to the IoT ecosystems, introducing additional Bluetooth interface to the above. The most popular series of these microcontrollers are:
The major difference is that ESP SoCs (both 8266 and 32) use 3.3 V logic, while most (but not all!) Arduinos use 5 V logic. This can be easily handled using one or bi-directional voltage converters/adapters. Additionally, many ESP boards and development kits offer double power source, including 5 V, even if the device itself still operates on 3.3 V
