WiFi LED Matrix Display

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parkview
Master Maker
Posts: 402
Joined: Tue Jun 24, 2014 8:25 pm
Location: Busselton
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WiFi LED Matrix Display

Post by parkview » Sun Sep 29, 2019 8:27 pm

While volunteering at the 2019 BSide cyber security conference: https://bsidesperth.com.au/, I came across a cute 16 x 16 LED Matrix display. This used an ESP8266 to host a WiFi access point to display a webpage that allowed you to draw patterns that could be submitted to be displayed onto the matrix. It was fun watching a group of young 13 year olds trying to write Javascript and Python programs to control the display.
LED-Matrix-front.jpg
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I realised I have one of these 16 x 16 LED matrix displays at home, so I set out this week to build my own display. Luckily I have designed and built my own ESP8266 LED PCB that included it's own 3.3V to 5V level translator built into it.
LED-Matrix-PCB.jpg
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I had previously purchased a 16 x 16 flexible LED display from the LED building in Shenzhen, but here is a random one from AliExpress: https://www.aliexpress.com/item/32894654401.html Look around and see if you can get a better price as they fluctuate.

All I had to do for the housing was cut out a white 2mm thick acrylic to act as a diffuser a 3mm thick spacer and a back spacer. I then designed up a mounting bracket for my ESP8266 PCB board and a suitable stand for the display. These where 3D printed out. I even designed up and 3D printed out a small cable tie down for the USB power cable.
LED-Matrix-back.jpg
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It's self supporting. I think the USB cable could perhaps be placed so that it's a bit better hidden, but I am expecting it to run from a power board USB socket, not from a battery power bank.
LED-Matrix-side.jpg
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Power usage at 30% LED brightness is 3.6W, or around 0.7A at 5V. I have placed some ceramic and a tantalum capacitor on the back of the LED matrix and my board doesn't seem to bothered by the noisy 5V power.

Overall, I am happy with this quick project. Thanks to the crew (Blake?) at the Perth Artifactory for the software: https://github.com/Perth-Artifactory/ar ... raw-matrix and project idea. I plan on taking this to China next week with me as a roving art display. I am sure it will make a fun talking point and people will have fun playing with it. Hopeful maybe even some Python code might be written to control the display.

parkview
Master Maker
Posts: 402
Joined: Tue Jun 24, 2014 8:25 pm
Location: Busselton
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Re: WiFi LED Matrix Display

Post by parkview » Mon Oct 07, 2019 12:16 pm

The LED Display Arduino code and webpage have now been updated to display a SW Maker logo. Three seconds after you turn on the Display, the colourful SW Maker logo is displayed:
swmakers-colour.jpg
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If you then attach your computer/mobile device onto the 'SWMakerDraw' LED Display Access Point, this webpage will automagically be displayed:
mobile-display.jpg
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You can this click on any of the buttons below and submit a pre-drawn image, or you can create your own image and display it.

This is the pre-drawn SW Maker logo:
SWMakers_LED-Display.jpg
SWMakers_LED-Display.jpg (38.85 KiB) Viewed 46 times

parkview
Master Maker
Posts: 402
Joined: Tue Jun 24, 2014 8:25 pm
Location: Busselton
Contact:

Re: WiFi LED Matrix Display

Post by parkview » Thu Oct 10, 2019 1:09 pm

Now that I have a working LED display on WiFi, I have configured to be either an independent WiFi Access Point, or at a push of a button, it can connect to a previously configured network (Static IP, or DHCP IP). I was walking the Shenzhen HQB electronics markets the other day and came across an ESP32-CAM for around A$11.70. This uses a OV2640 2MP camera and there is some cool Arduino code available for it.

Using this code: https://randomnerdtutorials.com/esp32-c ... assistant/ I quickly had a portable streaming video camera running from a 3.2V Li-ion battery. Here is a screenshot of the video stream of a section of the Shenzhen Steamhead Maker space:
video1.jpg
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From the screenshot, I wrote some Python code to shrink the jpg image down to 16x16 pixels and eventually (it took a while to figure it all out), managed to display the resultant image onto LED Matrix via WiFi:
video1.result.sml.jpg
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I can see further projects being based on this camera. I see that Seeed (as well as others) sell the raw camera module. It seems to work well with the ESP32 module.

* excuse the above photo quality. The camera still has the protective cover over the lens, and the LED matrix photo has reflections on it. The LED Matrix image has not been gamma corrected before being displayed. Thats for another day.

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