Specification: _x005f_x000D_ Power supply voltage: DC3.6V~5V input _x005f_x000D_ Onboard 18650 battery holder and charging circuit _x005f_x000D_ The maximum charging current of the battery is 0.5A _x005f_x000D_ The battery can be charged and discharged simultaneously _x005f_x000D_ WI-FI protocol: 802.11B/GN/D/E/K/R (802.11N, speed up to 150MBPS), aggregation of A-MPDU and A-MsDU, supporting 0.4US protection interval _x005f_x000D_ WiFi standard: FCC/CE/TELEO/KCC frequency range: 2.4-2.5GHz _x005f_x000D_ Bluetooth-compatible protocol: compliant with Bluetooth-compatible V4.2BR/EDR and BLE standards _x005f_x000D_ Bluetooth-compatible audio: CVSD and SBC audio _x005f_x000D_ On board 0.96 inch OLED screen _x005f_x000D_ Onboard red, green, and blue indicator lights _x005f_x000D_ Product size: 115 * 30 * 15mm/4.52 * 1.18 * 0.59inch _x005f_x000D_ _x005f_x000D_ Product function: _x005f_x000D_ 1. Connect the computer to upload the program: Connect the computer to download the program through a USB cable. Note: You need to keep pressing and holding the BOOT key while downloading the program _x005f_x000D_ 2. Battery connection: Place the 18650 battery into the module battery holder, which can be powered by the battery or charged through a USB port _x005f_x000D_ Red LED: Does not light up when charging the battery, remains on when it is about to be fully charged, and remains on when it is fully charged. Always on when not connected to battery, only connected to USB power supply _x005f_x000D_ Green LED: Always on when charging the battery, always on when it is about to be fully charged, and slightly flashing when fully charged _x005f_x000D_ Blue LED: IO16 signal light _x005f_x000D_ Dip switch: When the switch is turned to ON, the module enters the working state. When the switch is turned to OFF, the module exits the working state (the battery charging circuit is not affected by this switch) _x005f_x000D_ _x005f_x000D_ _x005f_x000D_ Note: _x005f_x000D_ Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! _x005f_x000D_ Please allow 1-2cm measuring deviation due to manual measurement. _x005f_x000D_ _x005f_x000D_ _x005f_x000D_ Included: _x005f_x000D_ 1 x Module 1. Powerful Functionality: The ESP32 WiFi wireless Bluetooth-compatible module with an 18650 battery slot and a 0.96-inch OLED development board is equipped with a new generation of WiFi and Bluetooth-compatible dual-mode, dual-core wireless communication chip, making it powerful and versatile. 2. Easy to Use: The module's main body uses the ESP-WROOM-32 module, and peripheral devices use the CP2102 USB-to-serial chip, which makes it easy to connect to a computer or device via USB for fast and stable data transmission. 3. Battery-Powered Option: With an 18650 battery slot, this module can be powered by batteries and charged simultaneously, providing high portability and convenience. 4. OLED Screen Display: With a 0.96-inch OLED display screen, this module provides clear and concise visual feedback, enhancing the user experience.