Using 16*2 display

16×2 LCD with I²C backpack (PCF8574) on Arduino/ESP boards. ✅ Hardware Connections Since it uses I²C, only 4 wires are required: LCD PinConnect to VCC5V GNDGND SDAESP8266 → D2 (GPIO4) / ESP32 → GPIO21 / Arduino Uno → A4 SCLESP8266 → D1 (GP...