Introduction: Proximity LED BackPack
My project is designed to detect an approaching object or subject up to 20cm thanks to the Proximity IR detector provided by my 27 Egeloo sensor kit.
Here is a list of what you need: List of items:
1. WS2812b Neo Pixel LED's
2. Power supply ( I used a 9V battery to power my Matrix and Uno) and a 22,000mA solar power charger.
3. 2 10k Resistor
4.Arduino Uno R3
5. Arduino Uno IDE: https://www.arduino.cc/en/Main/Software
6. Code: https://github.com/adafruit/Adafruit_NeoPixel (go to GitHub and download the code, open using the Arduino IDE software)
7. Jumpers and small gauge wires of black(Ground), red(power), and blue(data). They only need to able to support your maximum output/input wattage.
8. A backpack
9. Soldering Iron/ Solder
Step 1: The Code
After you have tested your Arduino and downloaded the IDE software. (FYI, there are great examples such as Blinky to test your Arduino Uno with built in the downloadable IDE software provided by Arduino). Now its time to test your Neo Pixels. After the test comes back positive you can move on to building your proximity backpack.
Step 2: The Matrix
You need to cut a piece of Worbla approximately, 4 1/2in W x 6 1/2in H. I choose Worbla because it is a very flexible material and this would come in handy being that my prop is a backpack. The assembly of the matrix (use the 144/pixels) is pretty straightforward. All you need to do is cut 2" to 2 1/4 inch groupings of the data, power, and ground cables. you need a total of 24 of them because you will use them to connect each section of the strand in order. The 144/pixel will need to be in cut strands of 12 pixels or 2 1/4in long. Now, the best practice while sodering your sections is to stop and check to see if they are working as you go. Trust me, this will save you a lot of time and heartache. Once your matrix is completed, it's time to test the code again to make sure it works. Success! Time to build the rest.
Step 3: 30/pixels and Backpack
The 30/pixels are easier to deal with but you have 5 meters of these LED's so good luck. I did not want to trim off my LED's because I was afraid of creating too many broken connections. This is a problem if you do not soder your power, ground or data properly, so take your time and be careful. Check your code one more time to make sure all the connections work and move on to the next step. I used brass wire to create a wired/electronic look to my backpack. I wanted it to look as much as a machine as possible. I believe that this was a successful approach, but I am considering sewing the 30/pixel LEDs onto the backpack for a clean look. Time to splice our wires and clean-up our mess. I used a small box to hold my Arduino and 9V battery. I also used twist ties to gather my wires in groups from the front to the back of the backpack.
Step 4: Organizing and Power
Staying organized is very important when dealing with so many wires. I found myself mixing up wires often. The best practice is to unplug your Arduino and make sure that you are using the correct ports first before adding power. Splitting a USB cable and pulling only the black and red cable, you can now connect your power cell to your WS2812b 30/pixels. I discovered that the additional ground to the Arduino is not needed when using this build. Only use one ground. Time for the 144/pixels, so connect the ground, data, and power cable directly to the Arduino for the matrix. This method consumes the life of the 9V quickly, but it gave me the best results. I will try to connect it to the power cell next time.
Step 5: Conclusion
The proximity IR detector worked successfully with my original code, but I wanted to have more cycles and a brighter experience. I discovered that I did not have enough power available to my LED's to pull this off, so I had to return to my original test code to wrap up this project. I feel that overall this was still a successful experiment and build. I hope much luck to anyone that wants to build there own and be mindful of power draws/requirements that was something that I did not discover to be a big issue until the end. I am posting my final video to show the backpacks full capability. The 9V battery does die during the video, but you will get to see the overall success of my proximity backpack. Thanks and Salute:-)
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