Introduction: App Controlled LED Matrix Wearable
Time Lapse Build
Video explaining the different power options
- PIXEL Maker's Kit from Seeedstudio - $59
- 16x32 LED Matrix from Adafruit or Seeedstudio - $25
- Gold chain (30 inches) - repurposed from a women's purse or http://www.hiphopbling.com - $10
- 2 D-hooks - picture frame hanging hooks
- 2 M3 stand-off screws
- 2000 mAH LiPo battery + LiPo 5V converter + charger from Seeed or PowerBoost 500 from Adafruit OR any normal cell phone battery pack + USB to DC jack cable (LiPo battery is recommended) - $20 . You'll get about 7 hours of continuous usage with the 2000 mAH LiPo depending on which animations are running.
- Metallic gold spray paint - $7
- 3 Gross (one gross is 144 crystals) 4.7mm 20ss crystals in the color of Light Colorado Topaz - either Genuine Swarovski ($32) or Swarovski imitation ($16)
- 1/2 Gross (72 crystals) 12ss Genuine Swarovski ($3.50) or Swarovski Imitation ($1.20)
- E6000 Craft Glue
- Jeweler's wax pick (for placing the crystals)
Disclosure: I am the creator of the PIXEL board used in this project. The PIXEL board was a collaboration with my good friend Ytai Ben-Tsvi and is an adaptation of Ytai's IOIO board. I had done a previous Kickstarter project called PIXEL using similar LED displays. Several of the my Kickstarter backers asked for a portable version of PIXEL which was the inspiration for this project.
Step 1: Flash PIXEL Board With Low Power Firmware
You'll need to re-flash the PIXEL board with the low power firmware. This is a must do, the 2000 mAH LiPo + 5V converter or phone battery pack will not be able to supply enough power to use the normal PIXEL firmware.
Follow these instructions to flash the board:
1. Cut power to the PIXEL board.
2. Unplug the Bluetooth dongle
3. Move the toggle switch on the board to the "Device" position
4. Using the USB A-A cable that came with the PIXEL board, plug one end into the PIXEL board and the other end into your PC or Mac
5. Download the PIXEL firmware upgrade application for PC or Mac (scroll down to the PIXEL firmware section on the page)
7. Find the port of the PIXEL board detected by your PC or Mac. The firmware application will provide instructions how to find the PIXEL board port.
8. While the PIXEL board is off, hold down the push button on PIXEL's circuit board and then power on with the button still held down
- The green LED on PIXEL's circuit board will be on - Release the push button and the green LED will blink 3-4 times indicating PIXEL is ready to accept the new firmware
9. Follow the instructions in the application to upgrade the firmware
Step 2: Quick Wire Up Test
Before proceeding, wire everything up to ensure all is working.
IMPORTANT: Move the toggle switch on the board back to the "Host" position and plug back in the Bluetooth dongle.
Connect the IDC cable (ribbon cable) from the PIXEL board to the LED matrix and the 4-pin power cable from the PIXEL board to the LED matrix. Both cables are notched and can only go in one way.
Plug in power to the DC jack of the PIXEL board.
Note that the PIXEL board will come with an on/off switch which plugs into the PIXEL board. The on/off switch isn't really needed in a portable installation like this so you may cut out the on/off switch and splice the wires together as in the picture above.
Now proceed to Step 3 and get the Android app to test displaying a GIF animation.
Step 3: Get the Android Apps
Android - Get the GIF Animations App - Free App
I wrote the apps to be compatible with older Android devices too, it should work on Android devices back to version 2.2. The Android device must have Bluetooth however.
If you don't have an Android, you can also program the display using the desktop application for PC and Mac, you'll just sacrifice the wearable interactivity. Or consider grabbing an older Android device off eBay which typically can be had for $40 - $50 USD.
After getting the Android apps, first Bluetooth pair to PIXEL using code: 0000 and then go to the Settings in the App and choose "PIXEL Model", the default will be "PIXEL 32x32", change this to "Adafruit 16x32". This tells the Android app what kind of LED matrix to use.
You can use the existing GIFs in the app or add your own. The included GIFs were a collaboration with pixel artists all over the world. To add your own GIFs, share any GIF using the Android share feature. The app will automatically re-size the GIF to 16x32. Higher resolution GIFs will not turn out well so stick to lower resolution GIFs and pixel art. Note the GIF app also supports sending a picture from your camera phone to the display.
Be sure and check out the scrolling text app too, that one also has a Twitter search feed feature turning yourself into a walking Twitter feed.
The apps will allow you to stream GIFs, still PNGs, and scrolling text from your phone over Bluetooth. And if you want a particular GIF, PNG, or scrolling text to persist, then long tap from the app which will then do a write to the board's microSD card. Now your selection will play and loop without the need to have your Phone Bluetooth connected.
Step 4: Disassemble LED Matrix Case
Before spray painting, you're going to need to disassemble the LED matrix case. Undo all the small screws on the front of the LED matrix.
Step 5: Spray Paint Gold
Spray paint the black bezel cover and back case of the LED matrix. DO NOT spray paint the LED matrix board itself.
Step 6: Reassemble LED Matrix Case
After the paint has dried, reassemble the LED matrix. You'll see that the black LED matrix screws stand out now, kind of ruining the effect. So best to paint those black screws gold too. I didn't have any matching gold paint around nor a fine tip brush but improvised by spraying the gold spray paint into a container and then dabbing the paint on the screws with a Q-tip which worked just fine.
In hind sight, it would have been easier to paint the top of the black screws with the gold paint before screwing them in. Just be sure and paint only the screw heads and not the threaded part as the screws are a tight fit and will not go in if the threads are painted.
Step 7: Crystallize
This step is optional but I'd recommend if you want the full bling effect.
I used genuine Swarovsky crystals but I also bought a batch of the imitation Swarovsky crystals from rhinestone biz.com. The Swarovsky ones do shine a bit more but I must say the imitation ones are pretty darn good too. If you put them side by side, you can tell the difference but you'll be just fine with the imitation ones if you want to save a little. Use the smaller 12ss size crystals for the just the ends where you have a small space to fill.
Here's a good tutorial on how to apply Swarovsky flat back crystals. Note: Do not use hot fix Swarovsky crystals, these are only good for adhering to fabric and porous materials.
Use E6000 craft glue with a syringe. This video explains how to insert the glue into the syringe.
Step 8: Final Assembly
Video of final assembly
The video illustrates how to do the final assembly. A few pointers:
- The 2000 mAH LiPo battery is located under the PIXEL board and is hot glued to the LED matrix
- Mount the PIXEL board with hot glue as far to the left as possible as you'll want to leave the most amount of clearance between the Bluetooth dongle and the LED matrix power connector. This is because if you ever want to flash the firmware in the future, you'll need to unplug the Bluetooth dongle and plug in the USB A-A cable.
- Fold over the LED matrix ribbon cable and hot glue to the PIXEL board.
- Use your flush cutter pliers and snip off the leads on the bottom of the PIXEL board. Otherwise, they will dig into the LiPo battery.
- Leave enough clearance for the LiPo circuit such that you can plug in the USB cable to charge. I simply hot glued a couple pieces of acrylic to give it enough height. The acrylic underneath the LiPo circuit also prevents a short circuit between the LiPo circuit and the LED matrix.
Step 9: 32x32 Version - 1,024 LEDs
I also made a larger 32x32 version.
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