ESP32 is a low-cost Wi-Fi and Bluetooth chip from Espressif Systems. ESP32 integrates Wi-Fi (2.4 GHz band) and Bluetooth 4.2 solutions on a single chip. It also supports classic Bluetooth for legacy connections such as L2CAP, SDP, GAP, SMP, AVDTP, AVCTP, A2DP (SNK), and AVRCP (CT). ESP32 also supports Bluetooth Low Energy (BLE), which covers L2CAP, GAP, GATT, SMP, and GATT-based profiles. A detailed product review of the ESP32 chip/module can be found at the following link: https://www.espressif.com/en/products/hardware/esp32/.
There are two forms for ESP32: chip form and module form. ESP32 chip and module forms have different sizes and numbers of pins. Choosing ESP32 form is dependent on your design and purposes. The size factor of ESP32 form can also be one of your preferences when you make and design an IoT solution-included PCB scheme. A list of ESP32 chips and modules can be read on the following website: https://www.espressif.com/en/products/hardware/modules.
Next, we will review some development boards that use the ESP32 chip or ESP32 module.