{"product_id":"i2c-backpack-pcf8574-i2c-adapter-for-lcd-displays","title":"I2C Backpack – PCF8574 I2C Adapter for LCD Displays","description":"\u003ch1\u003eI2C Backpack – PCF8574 I2C Interface for Character LCDs\u003c\/h1\u003e\u003cp\u003eThe I2C Backpack is a compact module that adds I2C communication to standard character LCDs using the PCF8574 I\/O expander. It reduces the numerous parallel connections to just two data lines, simplifying wiring for Arduino, Raspberry Pi, and other microcontrollers. Ideal for projects needing a display with minimal pin usage.\u003c\/p\u003e\u003ch2\u003eKey Specifications\u003c\/h2\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eI2C Address\u003c\/td\u003e\n\u003ctd\u003e0x27 (configurable 0x20-0x27)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChip\u003c\/td\u003e\n\u003ctd\u003ePCF8574T\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Voltage\u003c\/td\u003e\n\u003ctd\u003e2.5-6V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatibility\u003c\/td\u003e\n\u003ctd\u003e16x2, 20x4 character LCDs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInterface\u003c\/td\u003e\n\u003ctd\u003eI2C, 2-wire (SDA, SCL)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e41.5 x 19.5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch2\u003eWhat You Can Build With This\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/products\/pi-pico-temperature-display-kit-with-oled-beginner-stem-learning\"\u003eDigital clock with temperature display\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003eSystem status monitor for IoT devices\u003c\/li\u003e\n\u003cli\u003eMenu-driven interface for robotics projects\u003c\/li\u003e\n\u003cli\u003ePortable data logger with screen output\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eCompatibility\u003c\/h2\u003e\u003cp\u003eWorks with any 5V or 3.3V microcontroller that supports I2C, including Arduino Uno, Nano, Mega, Raspberry Pi, ESP8266, and ESP32. Simply solder the backpack to the LCD's 16-pin header, connect VCC, GND, SDA, and SCL.\u003c\/p\u003e\u003ch2\u003eWiring Notes\u003c\/h2\u003e\u003cp\u003eFor Arduino Uno, connect SDA to A4 and SCL to A5. On newer boards with dedicated I2C pins, use those. Ensure pull-up resistors (typically 4.7kΩ) are present on SDA and SCL lines if not built-in. The backpack operates at 5V but is tolerant of 3.3V I2C signals.\u003c\/p\u003e\u003ch2\u003eWhy Buy from Compoden\u003c\/h2\u003e\u003cp\u003eEvery component is sourced from verified suppliers and tested for compatibility before listing. We've spent 10 years building projects for makers, schools, and institutions across India. Ships from Bengaluru in 3-5 days. If defective on arrival, replace within 7 days.\u003c\/p\u003e\u003cdetails\u003e\u003csummary\u003eIs this compatible with Arduino Uno?\u003c\/summary\u003e\u003cp\u003eYes, the I2C Backpack works directly with Arduino Uno. Use the LiquidCrystal_I2C library for simple integration.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eCan I adjust the I2C address?\u003c\/summary\u003e\u003cp\u003eThe default address is 0x27 but can be changed by bridging solder pads (A0, A1, A2) to set addresses 0x20-0x27.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eWill it work with a 20x4 LCD?\u003c\/summary\u003e\u003cp\u003eAbsolutely. The backpack supports all character LCDs using the HD44780 controller, including 20x4 and 16x2 variants.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdiv class=\"compoden-handoff\" style=\"margin-top:24px;padding:16px;background:#f0f4ff;border-left:4px solid #2B4D8F;border-radius:4px;\"\u003e\n  \u003cp style=\"margin:0 0 6px 0;font-weight:600;color:#1A3560;\"\u003e📦 Free Setup Handoff Document Included\u003c\/p\u003e\n  \u003cp style=\"margin:0;font-size:0.95em;color:#333;\"\u003eEvery Compoden order includes a free setup handoff document — step-by-step instructions to get your component working within minutes. Download it via QR code on your package. The handoff document is also trained to help you troubleshoot the majority of problems.\u003c\/p\u003e\n\u003c\/div\u003e\n","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53445042110829,"sku":"CDN-0848","price":85.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/image_1_63dda357-8fc1-4788-b0c4-4126e25ba5d3.jpg?v=1781513032","url":"https:\/\/compoden.com\/products\/i2c-backpack-pcf8574-i2c-adapter-for-lcd-displays","provider":"Compoden","version":"1.0","type":"link"}