Part 1: Demo Video

Part 2: Tutorial Video

Schematic Diagram

Code

// // Hello YouTube! on ESP-12 and AdaFruit I2C LED Matrix // Hari Wiguna, 2015 // #include <Wire.h> #include "Adafruit_LEDBackpack.h" #include "Adafruit_GFX.h" Adafruit_8x8matrix matrix = Adafruit_8x8matrix(); int offset = 0; String msg = " Hello YouTube! "; int msgLength = msg.length(); void setup() { pinMode(A0, INPUT); Wire.pins(0,2); // <-- IMPORTANT!!! call this BEFORE initializing AdaFruit matrix (which calls wire.begin() with no parameters! matrix.begin(0x70); // pass in the address } void loop() { // Draw the message with increasing negative offset to "scroll" it for (int i = 0; i < msgLength; i++) matrix.drawChar(i*6 - offset, 0, msg[i], 1, 0, 1); matrix.writeDisplay(); // Actually update the display if (offset++ >= msgLength*6) offset = 0; // NOTE: ESP8266's ADC pin has a max of 1V that maps to 1023 // See Voltage Divider in wiring diagram. int potentiometer = analogRead(A0); int dly = map(potentiometer, 0, 950, 300, 30); // In theory upper should be 1023, but in practice it only reach 1000 delay(dly); }