Description: -One AD inputs; Micro USB inputs. One programmable LED (D0). Integrated 18650 battery charging and discharging system. -One switch controls whether the 18650 battery is powered or not. -for OLED's SDA and SCL connect to the D1 pin and the D2 pin respectively. -The five buttons are controlled by FLATH, RSET, D5, D6, and D7 respectively. The 5 Digital pins can configure the write/read/interrupt/pwm/I2C/one-wire supported separately. -Its operation is consistent with NodeMCU, adding a programmable LED, you can use with GPIO16 to control, display 8266 running status and other functions. Specification: Type: Electronic materials Model: ESP-8266 Charging Protection: Yes Discharge Protection: Yes Compatible With Arduino Compatible With NodeMCU Wide Voltage Input Range: 5V~12V Charge Current: 500 mA Size(L*W*H): 102 x 30 x 20 mm Display Size: 0.96 Inch Package Includes: 1 piece ESP8266 WiFi Module Note: This product does not contain 18650 batteries. If the battery is in the wrong direction, the charging chip will be destroyed. Please do not burn the program during charging. When you burn the program, please unplug the battery and verify the switch is in ON position. Recommend the use of 5V 500mA charging charger, more than 5V 1A there will be fever, does not affect the normal work, but in the process of charging charging chip do not touch or carry, the measured charge charging will rise to about 60 degrees with the diode chip, no heat during normal working hours, rest assured to carry