Adafruit Charlieplexed LED Matrices 16x 9
- Adafruit 2972, The Adafruit Charlieplexed Green LED 9x 16 Matrices give you boards full of bling with 144 x 0603 surface mount LEDs. With traditional multiplexing you would need 25 GPIO lines (9 + 16) to drive these boards which would soak up most of the signals on common microcontrollers. However, these boards are Charlieplexed, which is a clever way of doing more with less, using only 18 GPIOs. They can best be described as lean at only 2.4mm thick & 43.3 by 27.8mm (1.7 x 1.1 x 0.09in.). The boards don't have any limiting resistors or drivers, it's just the LEDS, so you can use them at whatever voltage suits your microcontroller. Adafruit have a free tutorial to get you started. Charlieplexing can be a daunting thing when you first see it & for those times when you just want to get something working without the fuss there's the Adafruit Charlieplexed PWM Matrix Driver (73-5266). This driver board is exactly the same size as the matrix board & is pin for pin compatible, just pop in a couple of double sided headers to get an LED matrix with I2C driver. Importantly the driver boards have PWM, meaning that the LEDs are individually dimmable which is rare for a single colour LED matrix. Adafruit 2972 Charlieplexed LED Matrix Green 16x 9