{"product_id":"adafruit-trellis-monochrome-driver-pcb-for-4x4-keypad-3mm-leds","title":"Adafruit Trellis Monochrome Driver PCB for 4x4 Keypad \u0026 3mm LEDs","description":"\u003cp\u003eTrellis is an open source backlight keypad driver system. It is easy to use, works with any 3mm LEDs and eight tiles can be tiled together on a shared I2C bus. \u003cspan\u003eEach Trellis PCB has 4x4 pads and 4x4 matching spots for 3mm LEDs.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThis item is just for the Trellis driver PCB assembly: LEDs and \u003ca href=\"https:\/\/shop.pimoroni.com\/products\/adafruit-silicone-elastomer-4x4-button-keypad-for-3mm-leds\"\u003ebuttons\u003c\/a\u003e not included.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eYou'll probably need the matching button pad, as well as some 3mm diffused LED's. Some soldering will is required for construction. The PCB doesn't contain a microcontroller so you'll also need an Arduino or similair to read the keypress data and let it know when to light up the LED's.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eThe circuitry on-board handles the background key-presses and LED lighting for the 4x4 tile.\u003c\/li\u003e\n\u003cli\u003eEach tile has an I2C-controlled LED sequencer and keypad reader already on it.\u003c\/li\u003e\n\u003cli\u003eThe chip controls all 16 LEDs individually, turning them on or off (no grayscale or dimming) as well as reading any keypresses made with the rubber keypad.\u003c\/li\u003e\n\u003cli\u003eThe connections are 'diode multiplexed' so you do not have to worry about \"ghosting\" when pressing multiple keys, each key is uniquely addressed.\u003c\/li\u003e\n\u003cli\u003eEach LED is multiplexed with a constant-current driver, so you can mix and match any colors you like. Any 3mm LED can be used, although we find that diffused LEDs with 250mcd+ brightness look best. \u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eNeed more than 4x4 buttons? No problem, the tiles have 3 address jumpers and you can tile up to 8 PCB's together on a single I2C bus, as long as each one has a unique address. That's up to 128 LED's and buttons using only 2 I2C wires!\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003etiles connect by the edges with solder, and share the same power, ground, interrupt, and i2c clock\/data pins.\u003c\/li\u003e\n\u003cli\u003econnect the tiles in any configuration you want as long as each tile is connected to another with the 5 edge-fingers.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eFor more information, check out Adafruit's \u003ca href=\"https:\/\/github.com\/adafruit\/Adafruit_Trellis_Library\"\u003eArduino library and example code\u003c\/a\u003e and their \u003ca href=\"https:\/\/learn.adafruit.com\/adafruit-neopixel-uberguide\"\u003e\u003cspan style=\"line-height: 1.2;\"\u003etutorial with wiring diagrams, installation instructions and example code!\u003c\/span\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"Adafruit","offers":[{"title":"Default Title","offer_id":440558137,"sku":"ADA1616","price":9.95,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0174\/1800\/products\/1616.jpg?v=1386786488","url":"https:\/\/shop.pimoroni.com\/en-eu\/products\/adafruit-trellis-monochrome-driver-pcb-for-4x4-keypad-3mm-leds","provider":"Pimoroni Ltd","version":"1.0","type":"link"}