What's better than a single LED? A fun way to make a small display is to use an 8x8 matrix or a 4-digit 7-segment display. Matrices like these are 'multiplexed' - so to control 64 LEDs you need 16 pins. That's a lot of pins, and there are driver chips like the MAX7219 that can control a matrix for you but there's a lot of wiring to set up and they take up a ton of space. Here at Adafruit we feel your pain! After all, wouldn't it be awesome if you could control a matrix without tons of wiring? That's where these adorable LED matrix backpacks come in. We have them in quite a few flavors! Classic 1.2" 8x8 (round and square dots) 4-digit 0.54" 14-segment Alphanumeric The matrices use a driver chip that does all the heavy lifting for you: They have a built in clock so they multiplex the display. They use constant-current drivers for ultra-bright, consistant color (the images above are photographed at the dimmest setting to avoid overloading our camera!), 1/16 step display dimming, all via a simple I2C interface.

The backpacks come with address-selection jumpers so you can connect up to four mini 8x8's or eight 7-segments (or a combination, such as four mini 8x8's and four 7-segments, etc) on a single I2C bus. The product kit comes with a fully tested and assembled LED backpack, a 4-pin header and the matrix of your choice. A bit of soldering is required to attach the matrix onto the backpack but its very easy to do and only takes about 5 minutes. Of course, in classic Adafruit fashion, we also have a detailed tutorial showing you how to solder, wire and control the display. We even wrote a very nice library for the backpacks so you can get running in under half an hour, displaying images on the matrix or numbers on the 7-segment. If you've been eyeing matrix displays but hesitated because of the complexity, his is the solution you've been looking for!A fun way to make a small colorful display is to use a 1.2" Bi-color 8x8 LED Matrix. Matrices like these are 'multiplexed' - so to control all the 128 LEDs you need 24 pins.

That's a lot of pins, and there are driver chips like the MAX7219 that can help control a matrix for you but there's a lot of wiring to set up and they take up a ton of space. samsonite intellio laptop backpack 16We have them in three flavors - a mini 8x8, 1.2" Bi-color 8x8 and a 4-digit 0.56" 7-segment. kulkea backpackThey work perfectly with the matrices we stock in the Adafruit shop and make adding a bright little display trivial. borderlands backpack glitch ps3It's called a Bicolor LED, but you can have 3 colors total by turning on the red and green LEDs, which creates yellow. lollygag backpack

That's 3 colors for the price of 2!They use constant-current drivers for ultra-bright, consistent color, 1/16 step display dimming, all via a simple I2C interface. gateway ozark backpack for saleThe backpacks come with address-selection jumpers so you can connect up to four mini 8x8's or eight 7-segments/bicolor (or a combination, such as four mini 8x8's and two 7-segments and two bicolor, etc) on a single I2C bus.pso2 backpack The product kit comes with: A bit of soldering is required to attach the matrix onto the backpack but its very easy to do and only takes about 5 minutes.now you're ready to run the firmware! Mini 8x8 Matrix Software We wrote a basic library to help you work with the mini 8x8 matrixThe library is written for the Arduino and will work with any Arduino as it just uses the I2C pins.

The code is very portable and can be easily adapted to any I2C-capable micro.Wiring to the matrix is really easy Connect CLK to the I2C clock - on Arduino UNO thats Analog #5, on the Leonardo its Digital #3, on the Mega its digital #21 Connect DAT to the I2C data - on Arduino UNO thats Analog #4, on the Leonardo its Digital #2, on the Mega its digital #20 Connect GND to common ground Connect VCC+ to power - 5V is best but 3V also seems to work for 3V microcontrollers. Next, download the Adafruit LED Backpack library from github . To download click the DOWNLOADS button in the top right corner, rename the uncompressed folder Adafruit_LEDBackpack. Check that the Adafruit_LEDBackpack folder contains Adafruit_LEDBackpack.cpp and Adafruit_LEDBackpack.h Place the Adafruit_LEDBackpack library folder your arduinosketchfolder/libraries/ folder. You may need to create the libraries subfolder if its your first library. You'll also need to download the Adafruit GFX library that provides the graphics drawing routines.

Once you've restarted you should be able to select the File->Examples->Adafruit_LEDBackpack->matrix88 exampleUpload it to your Arduino as usual. You should see a basic test program that goes through a bunch of different drawing routine Once you're happy that the matrix works, you can write your ownThe 8x8 matrix supports everything the Adafruit GFX library - drawing pixels, lines, rectancles, circles, triangles, roundrects, andFor more details check out the GFX page which will detail all of the GFX routines. All the drawing routines only change the display memory kept by the Arduino. Don't forget to call writeDisplay() after drawing to 'save' the memory out to the matrix via I2C. There are also a few small routines that are special to the matrix: setBrightness(brighness)- will let you change the overall brightness of the entire display. 0 is least bright, 15 is brightest and is what is initialized by the display when you start. You can call this function at any time to change the brightness of the -entire- display