ITEM NAME:Ttgo Expression Panel Blue Led Display Board Module For Esp32 Esp8266 For A U8Y5 Ttgo Expression Panel Blue Led Display Board Module For Esp32 Esp8266 For A U8Y5 Brand Name:TTGO The expression panel contains a total of 128 aligned LEDs. The color is blue. By receiving data from the motherboard, you can control the display of numbers, letters, or symbols. There are I2C pins on the connector that can be connected. Pin definition Operating voltage: 5V DC Communication Mode: I2C The expression panel module has 4 pins. Their functions are as follows No.- Pin - Function: 1 - DIN - Data 2 - SCK - Clock 3 - 5V - Power supply 4 - GND - Ground Pin Schematic colour:black Material:Metal + PC Package Contents: 1 * LED display board 4 * Pin line.Their functions are as follows. The color is blue. There are I2C pins on the connector that can be connected. 1 LED display board. 4 Pin line. 4 - GND - Ground.