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IS31FL3731 16x9 Charlieplexed PWM LED Driver Created by lady ada https://learn.adafruit.com/i31fl3731-16x9-charliplexed-pwm-led-driver Last updated on 2022-07-18 08:11:41 PM EDT ©Adafruit Industries Page 1 of 44 Table of Contents Overview 5 Pinouts 7 • • • • Power Pins I2C Data Pins Other Control Pins LED Grid Assembly • • • • • • • • • 11 Assemble the IS31 Driver Board Prepare the header strip: Add the breakout board: And Solder! Solder Driver Headers for LEDs Prepare the header strip: Add the breakout board face up: And Solder! Attach LED panel Arduino Wiring & Test 21 • Wiring • Download Libraries • Load Demo Library Reference • • • • Initialize Drawing Adafruit GFX Multiple Buffers Python & CircuitPython • • • • • • • 25 CircuitPython Microcontroller Wiring Python Computer Wiring CircuitPython Installation of IS31FL3731 Library Python Installation of IS31FL3731 Library CircuitPython & Python Usage Full Example Code Text Scrolling Example Python Examples • • • • • • • 23 35 Additional Setup DejaVu TTF Font Pillow Library Speeding up the Display on Raspberry Pi Scrolling Marquee Example Full Source Code Animated GIF Example Python Docs ©Adafruit Industries 42 Page 2 of 44 Downloads 42 • Datasheets & Files • IS31FL3731 Breakout • 16x9 0603 LED Grid ©Adafruit Industries Page 3 of 44 ©Adafruit Industries Page 4 of 44 Overview The IS31FL3731 will let you get back to that classic LED matrix look, with a nice upgrade! This I2C LED driver chip has the ability to PWM each individual LED in a 16x9 grid so you can have beautiful LED lighting effects, without a lot of pin twiddling. Simply tell the chip which LED on the grid you want lit, and what brightness and it's all taken care of for you. The IS31FL3731 is a nice little chip - it can use 2.7-5.5V power and logic so its flexible for use with any microcontroller. You can set the address so up to 4 matrices can ©Adafruit Industries Page 5 of 44 share an I2C bus. Inside is enough RAM for 8 separate frames of display memory so you can set up multiple frames of an animation and flip them to be displayed with a single command. This chip is great for making small LED displays, and we even designed the breakout to match up with our ready-to-go LED grids in red, yellow, green, blue and white. Sandwich the driver and matrix breakout, solder together for a compact setup. Or you can DIY your own setup, just follow the LED grid schematic in the IS31FL3731 datasheet. ©Adafruit Industries Page 6 of 44 Pick up a driver board and your favorite color LEDs to match. You'll need to do some basic soldering to attach the driver backpack and matrix together, and run wires to your microcontroller, but its not too hard. Then install our Arduino code to get some LEDs blinking immediately. Our library is Adafruit_GFX compatible so you can draw lines, circles, text, and small bitmaps if you want more graphics control Pinouts The IS31FL3731 has a lot of pins, and we wanted to make it easy to use with a breadboard while sandwiched with an LED matrix. The easiest way we could figure out to do this is make the board as large as our 0603-LED 16x9 matrix grids and have a control header on one edge. That way you can solder the two long headers directly to the matrix and still have access to pins for power and data. ©Adafruit Industries Page 7 of 44 Power Pins You can power the IS31 from 2.7-5.5VDC, but note that the same voltage is used for both power and logic. If you are using a 5V logic device, just connect VCC to 5V. If you are using a 3.3V logic, you can either power with 3.3V, which will work fine for red, yellow or light green LEDs or you can power from 5V and then use ~2.2K resistors from SDA and SCL to 3.3V to 'overpower' the built in 20K pullup resistors. I2C Data Pins ©Adafruit Industries Page 8 of 44 This chip uses I2C for control, it does not use clock stretching or repeated start. There are built in 20K pullups to VCC. You can run it as fast as 400KHz clock speed, but you may need to add additional 2K pullups from SDA and SCL up to VCC for higher speeds • SDA - I2C data line, connect to your microcontroller's I2C SDA pin • SCL - I2C clock line, connect to your microcontroller's I2C SCL pin Other Control Pins • SD - Shutdown pin, default pulled up to VCC. Connect to ground to put the chip in shutdown mode • AUD - Audio input, can be used to modulate the entire display with the amplitude of a line level audio signal, has a series capacitor installed. • ADDR and jumpers - By default the address is 0x74 but you can close one of the jumpers to change the address for up to 4 devices with varying addresses • INTB - Output interrupt from chip when using the built in animation modes LED Grid The LED Grid is much simpler, it just has 2 charlieplex grids, 16x9 total 0603 LEDs, with the two grids broken out to side pins that line up with the driver ©Adafruit Industries Page 9 of 44 ©Adafruit Industries Page 10 of 44 Assembly Assemble the IS31 Driver Board We'll start by soldering in the 7-pin 'control' header. Break the headers you received so that you have a 7-pin piece and follow these steps. Prepare the header strip: Cut the strip to length if necessary. It will be easier to solder if you insert it into a breadboard - long pins down ©Adafruit Industries Page 11 of 44 Add the breakout board: Place the breakout board over the pins so that the short pins poke through the breakout pads ©Adafruit Industries Page 12 of 44 And Solder! Be sure to solder all pins for reliable electrical contact. (For tips on soldering, be sure to check out our Guide to Excellent Soldering (https:// adafru.it/aTk)). ©Adafruit Industries Page 13 of 44 OK the control port header is done. Check your solder joints visually and continue onto the next steps Solder Driver Headers for LEDs The two side strips are what are used to control the charlie-plexed LEDs Prepare the header strip: Cut the strip to length if necessary. It will be easier to solder if you insert it into a breadboard - long pins down Add the breakout board face up: Place the breakout board over the pins so that the short pins poke through the breakout pads ©Adafruit Industries Page 14 of 44 And Solder! Be sure to solder all pins for reliable electrical contact. (For tips on soldering, be sure to check out our Guide to Excellent Soldering (https:// adafru.it/aTk)). ©Adafruit Industries Page 15 of 44 ©Adafruit Industries Page 16 of 44 OK now you have the control and LED pads with headers. Check your solder joints visually and continue onto the next steps Attach LED panel Now we'll sandwich on the charlieplexed LED panel The LEDs face out and connect to the two side header strips. The panel is symmetric - you can flip it around either way and it will work fine ©Adafruit Industries Page 17 of 44 Solder in the two long header strips. Not all are connected on the LED matrix but it makes the connections mechanically stable. ©Adafruit Industries Page 18 of 44 Check your solder joints visually and continue onto the next steps Now you can trim the long header with diagonal cutters. Cut one or two pins at a time Watch out for flying header bits. Wear eye protection and be careful! ©Adafruit Industries Page 19 of 44 Cut both sides down for the best look You're done! Check your solder joints visually and continue onto the next steps ©Adafruit Industries Page 20 of 44 Arduino Wiring & Test You can easily wire this breakout to any microcontroller, we'll be using an Arduino. For another kind of microcontroller, as long as you have I2C pins available, just check out the library, then port the code. Wiring Use this wiring if you want to connect via I2C interface • Connect Vin to the power supply, 3-5V is fine. Use the same voltage that the microcontroller logic is based off of. For most Arduinos, that is 5V • Connect GND to common power/data ground • Connect the SCL pin to the I2C clock SCL pin on your Arduino. On an UNO & '328 based Arduino, this is also known as A5, on a Mega it is also known as digit al 21 and on a Leonardo/Micro, digital 3 • Connect the SDA pin to the I2C data SDA pin on your Arduino. On an UNO & '328 based Arduino, this is also known as A4, on a Mega it is also known as digit al 20 and on a Leonardo/Micro, digital 2 ©Adafruit Industries Page 21 of 44 Download Libraries To begin reading sensor data, you will need to dowload the Adafruit IS31FL3731 librar y from the Arduino library manager. Open up the Arduino library manager: Search for the Adafruit IS31FL3731 library and install it Search for the Adafruit GFX library and install it If using an older (pre-1.8.10) Arduino IDE, locate and install Adafruit_BusIO (newer versions do this one automatically). We also have a great tutorial on Arduino library installation at: http://learn.adafruit.com/adafruit-all-about-arduino-libraries-install-use (https:// adafru.it/aYM) Load Demo Open up File->Examples->Adafruit_IS31FL3731->swirldemo and upload to your Arduino wired up to the driver & matrix ©Adafruit Industries Page 22 of 44 Upload to your Arduino, you'll see the LED display swirl different brightnesses! Library Reference Now that you have the demo working, you can control the matrix directly. Initialize Start by creating a new matrix object with something like: Adafruit_IS31FL3731 ledmatrix = Adafruit_IS31FL3731(); There's no arguments to the constructor ©Adafruit Industries Page 23 of 44 Then in your setup, call begin(address) to initialize the driver. Begin() will return false if the matrix was not found, and true if initialization worked out if (! ledmatrix.begin()) { Serial.println("IS31 not found"); while (1); } Serial.println("IS31 found!"); Drawing You can then draw to the display. Note that since we write directly to the driver RAM, any pixels 'drawn' will appear immediately. You can start with drawPixel(x, y, brightness) where x ranges between 0 and 15 inclusive, and y ranges between 0 and 8 inclusive. Brightness is the PWM of the LED, 0 is off, and 255 is all the way on. This loop will light up every LED in increasing brightness: int i = 0; for (uint8_t x=0; x> prompt. Python Installation of IS31FL3731 Library You'll need to install the Adafruit_Blinka library that provides the CircuitPython support in Python. This may also require enabling I2C on your platform and verifying you are running Python 3. Since each platform is a little different, and Linux changes often, please visit the CircuitPython on Linux guide to get your computer ready (https: //adafru.it/BSN)! Once that's done, from your command line run the following command: • sudo pip3 install adafruit-circuitpython-is31fl3731 adafruitcircuitpython-framebuf If your default Python is version 3 you may need to run 'pip' instead. Just make sure you aren't trying to use CircuitPython on Python 2.x, it isn't supported! CircuitPython & Python Usage To demonstrate the usage of the sensor we'll initialize it and manipulate the LED matrix from the board's Python REPL. NOTE: Due to size and design of each CharliePlex matrix form-factor, import and initialisation is different for each. Make sure you're running the correct code for your matrix! First, run the following code to import the necessary modules: ©Adafruit Industries Page 28 of 44 import board import busio If you're using the CharliePlex breakout, initialise it by running the following code: from adafruit_is31fl3731.matrix import Matrix as Display If you're using the CharliePlex FeatherWing, run the following code: from adafruit_is31fl3731.charlie_wing import CharlieWing as Display If you're using the CharliePlex Bonnet, run the following code: from adafruit_is31fl3731.charlie_bonnet import CharlieBonnet as Display Now, no matter which board you are using, you'll create the I2C object and pass that into Display . i2c = busio.I2C(board.SCL, board.SDA) display = Display(i2c) When the display initializes it will go through and clear each frame (there are 8 frames total) of the display. You might see the display momentarily flash and then turn off to a clear no pixel lit image. You can control all of the board's pixels using the fill function. Send to this function a value from 0 to 255 where 0 is every LED pixel turned off and 255 is every LED pixel turned on to maximum brightness. For example to set all the pixels to half their brightness run: display.fill(127) ©Adafruit Industries Page 29 of 44 You might notice some buzzing or ringing sounds from the display when all pixels are lit, this is normal as the Charlieplex driver quickly switches LEDs on and off. If you've used other displays like LED matrices you might notice the Charlieplex module doesn't need to have a show function called to make the changes visible.  As soon as you call fill or other display functions the display will update! You can turn all the pixels off with fill set to 0 : display.fill(0) Be careful setting all pixels to 255 maximum brightness! This might pull more power than your computer's USB port can provide if you are powering your board over USB. Use an external powers supply or battery when lighting lots of LEDs to max brightness. Now for some fun!  You can set any of the LED pixels using the pixel function.  This function takes the following parameters: • X position - The location of the horizontal / X pixel position. • Y position - The location of the vertical / Y pixel position. • Intensity - This is a value from 0 to 255 which specifies how bright the pixel should be, 0 is off and 255 is maximum brightness.  Use an in-between value to show a less bright pixel. For example to set pixel 0, 0 to full brightness run: display.pixel(0, 0, 255) ©Adafruit Industries Page 30 of 44 Or to set the pixel next to it horizontally to half brightness run: display.pixel(1, 0, 127) You can turn off individual pixels by setting them to an intensity of zero. You can even make pixels blink!  The board supports a fixed blink rate that you set using the blink function.  This function takes in the number of milliseconds to use for the blink rate (but internally it can only blink in 270ms increments so you might not get an exact match).  For example to blink pixels about once every half second call: display.blink(500) You'll notice nothing actually changes on the board. This is because in addition to intensity each LED pixel has a blink state which can be enabled and disabled. The fi ll command can actually set all pixels and turn them on to blink: display.fill(127, blink=True) You can turn off the blinking by setting blink=False . ©Adafruit Industries Page 31 of 44 The pixel command supports the blink parameter too!  You can turn on and off blinking pixel by pixel as needed.  For example to turn on blinking for pixel 0, 0 : display.pixel(0, 0, 127, blink=True) Currently the Charlieplex module is very simple and only exposes pixel set commands.  In the future more advanced graphics commands like line drawing, text display, etc. might be implemented but for now you'll need to manipulate the pixels yourself. Finally the display supports holding up to 8 frames of pixel data.  Each frame contains an entire matrix of LED pixel state (intensity, blinking, etc.) and by default the module starts you on frame 0.  You can change to start displaying and drawing on another frame by calling frame which takes these parameters: • Frame number - This is the frame number to make the active frame for display or drawing.  There are 8 frames total, 0 through 7 . • show - An optional boolean that defaults to True and specifies if the frame should be immediately displayed ( True ) or just made active so that pixel and fill commands draw on it but it's not yet shown. For example to clear frame 1 and draw a few pixels on it, then display it you can run: display.frame(1, display.fill(0) display.pixel(0, display.pixel(1, display.pixel(2, display.frame(1) show=False) 0, 1, 2, # 255) 255) 255) show=True is the default, the frame will be displayed! Notice how the first call switches to make frame 1 the active frame but doesn't display it because show is set to false. Then the frame pixel data is changed with fill and pixel ©Adafruit Industries Page 32 of 44 commands, and finally the frame is shown by calling frame again but letting the default show = True be used so the frame is displayed. Using frames you can build simple animations by drawing each frame and swapping between them over time! That's all there is to the basic Charlieplex driver module usage! Full Example Code # SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries # SPDX-License-Identifier: MIT import board import busio # uncomment next line if you are using Feather CharlieWing LED 15 x 7 from adafruit_is31fl3731.charlie_wing import CharlieWing as Display # # # # # # # # uncomment next line if you are using Adafruit 16x9 Charlieplexed PWM LED Matrix from adafruit_is31fl3731.matrix import Matrix as Display uncomment next line if you are using Adafruit 16x8 Charlieplexed Bonnet from adafruit_is31fl3731.charlie_bonnet import CharlieBonnet as Display uncomment next line if you are using Pimoroni Scroll Phat HD LED 17 x 7 from adafruit_is31fl3731.scroll_phat_hd import ScrollPhatHD as Display uncomment next line if you are using Pimoroni 11x7 LED Matrix Breakout from adafruit_is31fl3731.matrix_11x7 import Matrix11x7 as Display # uncomment this line if you use a Pico, here with SCL=GP21 and SDA=GP20. # i2c = busio.I2C(board.GP21, board.GP20) i2c = busio.I2C(board.SCL, board.SDA) display = Display(i2c) # draw a box on the display # first draw the top and bottom edges for x in range(display.width): display.pixel(x, 0, 50) display.pixel(x, display.height - 1, 50) # now draw the left and right edges for y in range(display.height): display.pixel(0, y, 50) display.pixel(display.width - 1, y, 50) Text Scrolling Example NOTE: When running this example on Raspberry Pi, you must have the font8x5.bin file found here (https://adafru.it/Edh) in the same directory as the program! wget https://raw.githubusercontent.com/adafruit/ Adafruit_CircuitPython_framebuf/master/examples/font5x8.bin ©Adafruit Industries Page 33 of 44 # SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries # SPDX-License-Identifier: MIT import board import busio import adafruit_framebuf # uncomment next line if you are using Feather CharlieWing LED 15 x 7 # from adafruit_is31fl3731.charlie_wing import CharlieWing as Display # uncomment next line if you are using Adafruit 16x9 Charlieplexed PWM LED Matrix # from adafruit_is31fl3731.matrix import Matrix as Display # uncomment next line if you are using Adafruit 16x8 Charlieplexed Bonnet from adafruit_is31fl3731.charlie_bonnet import CharlieBonnet as Display # # # # uncomment next line if you are using Pimoroni Scroll Phat HD LED 17 x 7 from adafruit_is31fl3731.scroll_phat_hd import ScrollPhatHD as Display uncomment next line if you are using Pimoroni 11x7 LED Matrix Breakout from adafruit_is31fl3731.matrix_11x7 import Matrix11x7 as Display # uncomment this line if you use a Pico, here with SCL=GP21 and SDA=GP20. # i2c = busio.I2C(board.GP21, board.GP20) i2c = busio.I2C(board.SCL, board.SDA) display = Display(i2c) text_to_show = "Adafruit!!" # Create a framebuffer for our display buf = bytearray(32) # 2 bytes tall x 16 wide = 32 bytes (9 bits is 2 bytes) fb = adafruit_framebuf.FrameBuffer( buf, display.width, display.height, adafruit_framebuf.MVLSB ) frame = 0 # start with frame 0 while True: for i in range(len(text_to_show) * 9): fb.fill(0) fb.text(text_to_show, -i + display.width, 0, color=1) # to improve the display flicker we can use two frame # fill the next frame with scrolling text, then # show it. display.frame(frame, show=False) # turn all LEDs off display.fill(0) for x in range(display.width): # using the FrameBuffer text result bite = buf[x] for y in range(display.height): bit = 1 0 then set the pixel brightness if bit: display.pixel(x, y, 50) # now that the frame is filled, show it. display.frame(frame, show=True) frame = 0 if frame else 1 ©Adafruit Industries Page 34 of 44 Python Examples If you want to expand the capabilities of the CharliePlex LED Matrix even more, we can add Pillow into the mix. So we'll show you how to add Pillow and then go over a couple of examples that use Pillow. Additional Setup If you haven't already installed the library, follow the setup section on the Python & CircuitPython page. If you have, then continue. DejaVu TTF Font Raspberry Pi usually comes with the DejaVu font already installed, but in case it didn't, you can run the following to install it: • sudo apt-get install ttf-dejavu Pillow Library We also need Pillow, also known as PIL, the Python Imaging Library, to allow using text with custom fonts. There are several system libraries that PIL relies on, so installing via a package manager is the easiest way to bring in everything: • sudo apt-get install python3-pil That's it. You should be ready to go. Speeding up the Display on Raspberry Pi For the best performance, especially if you are doing fast animations, you'll want to tweak the I2C core to run at 1MHz. By default it may be 100KHz or 400KHz To do this, edit the config with  sudo nano /boot/config.txt and add to the end of the file ©Adafruit Industries Page 35 of 44 dtparam=i2c_baudrate=1000000 Reboot to 'set' the change. Scrolling Marquee Example The first example, we're going to take a look at an example that will take some text, draw it in a TrueType font and then scroll the rendered text. Let's start by looking at the code in each section. We start by importing the libraries we need which include the board and a few Pillow modules. import board from PIL import Image, ImageDraw, ImageFont Next we do the import for the IS31FL3731 driver for the matrix itself. Since the different boards have been split into their own modules, we just import the appropriate module and alias it as Display . For instance, if you have the breakout instead of the bonnet, you'll want to uncomment that and comment out the bonnet line. # uncomment next line if you are using Adafruit 16x9 Charlieplexed PWM LED Matrix # from adafruit_is31fl3731.matrix import Matrix as Display # uncomment next line if you are using Adafruit 16x8 Charlieplexed Bonnet from adafruit_is31fl3731.charlie_bonnet import CharlieBonnet as Display # uncomment next line if you are using Pimoroni Scroll Phat HD LED 17 x 7 # from adafruit_is31fl3731.scroll_phat_hd import ScrollPhatHD as Display ©Adafruit Industries Page 36 of 44 Next we set a couple of variables. We have the SCROLLING_TEXT variable. Go ahead and change the text if you would like. It shouldn't matter how long, though you probably shouldn't make it too long if you want to see it loop. You can set BRIGHTNES S as well, in case you want to adjust the intensity. SCROLLING_TEXT = "You can display a personal message here..." BRIGHTNESS = 64 # Brightness can be between 0-255 Next we do the basic setup for the display by declaring the I2C object and passing that into the display. i2c = board.I2C() display = Display(i2c) Next we go ahead and load up the Deja Vu font into an object. We are going with an 8 pixel high font because that's the largest we can fit on the display and still see everything. # Load a font font = ImageFont.truetype('/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf', 8) In this next part, we first start by getting the width and height of what the text would be when rendered with the font we chose. Then we create a virtual image of that width and height and draw the text onto it. # Create an image that contains the text text_width, text_height = font.getsize(SCROLLING_TEXT) text_image = Image.new('L', (text_width, text_height)) text_draw = ImageDraw.Draw(text_image) text_draw.text((0, 0), SCROLLING_TEXT, font=font, fill=BRIGHTNESS) Next we create a virtual image that's the same size as the display. This will be where we draw what we want to actually display. # Create an image for the display image = Image.new('L', (display.width, display.height)) draw = ImageDraw.Draw(image) Finally we get to our main loop. We start by drawing a rectangle to be sure we are not leaving any existing text behind. Then we paste our image of the text onto the image we are going to display using the value of x , which represents the left offset we want to use to give a nice scrolling effect. We have a for loop which will scroll ©Adafruit Industries Page 37 of 44 the complete text plus empty display width by one iteration. That's all placed inside an infinite while loop for endless iterations. while True: for x in range(text_width + display.width): draw.rectangle((0, 0, display.width, display.height), outline=0, fill=0) image.paste(text_image, (display.width - x, display.height // 2 text_height // 2 - 1)) display.image(image) Now go ahead and run the example code. python3 is31fl3731_pillow_marquee.py You should see the display showing a message scrolling from right to left. Full Source Code # SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries # SPDX-License-Identifier: MIT """ Example to scroll some text as a marquee This example is for use on (Linux) computers that are using CPython with Adafruit Blinka to support CircuitPython libraries. CircuitPython does not support PIL/pillow (python imaging library)! Author(s): Melissa LeBlanc-Williams for Adafruit Industries """ import board from PIL import Image, ImageDraw, ImageFont ©Adafruit Industries Page 38 of 44 # uncomment next line if you are using Adafruit 16x9 Charlieplexed PWM LED Matrix # from adafruit_is31fl3731.matrix import Matrix as Display # uncomment next line if you are using Adafruit 16x8 Charlieplexed Bonnet from adafruit_is31fl3731.charlie_bonnet import CharlieBonnet as Display # uncomment next line if you are using Pimoroni Scroll Phat HD LED 17 x 7 # from adafruit_is31fl3731.scroll_phat_hd import ScrollPhatHD as Display SCROLLING_TEXT = "You can display a personal message here..." BRIGHTNESS = 64 # Brightness can be between 0-255 i2c = board.I2C() display = Display(i2c) # Load a font font = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf", 8) # Create an image that contains the text text_width, text_height = font.getsize(SCROLLING_TEXT) text_image = Image.new("L", (text_width, text_height)) text_draw = ImageDraw.Draw(text_image) text_draw.text((0, 0), SCROLLING_TEXT, font=font, fill=BRIGHTNESS) # Create an image for the display image = Image.new("L", (display.width, display.height)) draw = ImageDraw.Draw(image) # Load the text in each frame while True: for x in range(text_width + display.width): draw.rectangle((0, 0, display.width, display.height), outline=0, fill=0) image.paste( text_image, (display.width - x, display.height // 2 - text_height // 2 1) ) display.image(image) Animated GIF Example Next let's take a look at an animated GIF player example. First we'll start by downloading an animated GIF and copying that into the same folder as the script as a dafruit-star-rotating.gif. It looks tiny and that's because it is. It is 8x8 pixels which works out nicely for the CharliePlex matrix. Download Rotating Star https://adafru.it/HAk Now let's start with the first section, the imports. You may be surprised that this code uses fewer Pillow modules than the previous example. We are also adding sys , which we mostly use for passing the name of an animated gif. ©Adafruit Industries Page 39 of 44 import sys import board from PIL import Image import adafruit_is31fl3731 Next we do the usual setup for the CharliePlex display. i2c = board.I2C() # uncomment line if you are using Adafruit 16x9 Charlieplexed PWM LED Matrix #display = adafruit_is31fl3731.Matrix(i2c) # uncomment line if you are using Adafruit 16x9 Charlieplexed PWM LED Matrix display = adafruit_is31fl3731.CharlieBonnet(i2c) Now we make sure the user specified a gif file, so we have something to work with that's not hard-coded and open the file. If the file wasn't specified, we are using sys. exit() , since that is the preferred way to do it if you are importing sys anyways. # Check that the gif was specified if len(sys.argv) < 2: print("No image file specified") print("Usage: python3 is31fl3731_pillow_animated_gif.py animated.gif") sys.exit() # Open the gif image = Image.open(sys.argv[1]) We need to check that this is an animated gif. While we could have just displayed it as a static gif in this case, the point was to show how to display the animation. # Make sure it's animated if not image.is_animated: print("Specified image is not animated") sys.exit() Next we get some gif animation information such as the delay. Only the duration of the first frame is extractable at the time of this writing with Pillow. # Get the autoplay information from the gif delay = image.info['duration'] The loop number is a little trickier because it means different things between the IS31FL3731 chip and an animated gif. With an animated gif, it is guaranteed to play at least once and then loop by the number of times is provided by the loop value, unless it is zero, which means forever. With the IS31FL3731, loops mean exactly the number of loops to play the animation, unless it is zero, in which case it will play forever. ©Adafruit Industries Page 40 of 44 So if loop is 0, we just pass it on. If we only want to play the animation once, then l oop is not provided in the image information. If it is more than once, we need to count the first time it plays plus the number of times to loop the animation. # Figure out the correct loop count if "loop" in image.info: loops = image.info['loop'] if loops > 0: loops += 1 else: loops = 1 Next, we need to make sure these values are in the ranges that the driver likes. The number of frames in the animation is available from the property n_frames and the IS31FL3731 can handle a maximum of 8 frames, so if a longer animation is provided, only the first 8 frames are used. # IS31FL3731 only supports 0-7 if loops > 7: loops = 7 # Get the frame count (maximum 8 frames) frame_count = image.n_frames if frame_count > 8: frame_count = 8 Now that we have a frame count, we will go through each of those frames and load the frame image into the IS31FL3731 using the paste function and center the image. First the frame is converted to a 256-grayscale image, which is what mode L is, and then it is copied into a centered position, which is calculated from the difference in size between the display and image. After that, it is inserted as the current frame number. # Load each frame of the gif onto the Matrix for frame in range(frame_count): image.seek(frame) frame_image = Image.new('L', (display.width, display.height)) frame_image.paste(image.convert("L"), (display.width // 2 - image.width // 2, display.height // 2 - image.height // 2)) display.image(frame_image, frame=frame) Finally, we call the auto_play function using the delay and loop information from the animated gif. display.autoplay(delay=delay, loops=loops) Now go ahead and run the example code. ©Adafruit Industries Page 41 of 44 python3 is31fl3731_pillow_animated_gif.py adafruit-star-rotating.gif You should see the rotating star appear on the display. Python Docs Python Docs (https://adafru.it/C55) Downloads Datasheets & Files • EagleCAD PCB files on GitHub (https://adafru.it/oja) • Fritzing objects in the Adafruit Fritzing library (https://adafru.it/aP3) • IS31FL3731 Datasheet (https://adafru.it/lWC) IS31FL3731 Breakout Schematics & Fabrication Print (Dimensions in Inches) ©Adafruit Industries Page 42 of 44 16x9 0603 LED Grid Schematics & Fabrication print (dimensions in inches) ©Adafruit Industries Page 43 of 44 ©Adafruit Industries Page 44 of 44