LED screen teardown, driving LEDs with video, mikeselectricstuff writes –
I just took apart a piece of the commercial outdoor LED screen that used to be in London’s Piccadilly Circus. Also included is a detailed analysis of the drive waveforms etc. which may be of interest to people trying to seriously use the 32×16 RGB modules
We carry 32×16 and 32×32 LED wall sections in the shop! Complete with Arduino wiring diagrams and libraries.
32×32 RGB LED matrix panel! Bring a little bit of Times Square into your home with this totally adorable 5 inch square 32 x 32 RGB LED matrix panel. These panels are normally used to make video walls, here in New York we see them on the sides of busses and bus stops, to display animations or short video clips. We thought they looked really cool so we picked up a few boxes of them from a factory. They have 1024 bright RGB LEDs arranged in a 32×32 grid on the front. On the back there is a PCB with two sets of dual IDC connectors (two input, two output: in theory you can chain these together) and 12 16-bit latches that allow you to drive the display with a 1:16 scan rate.
These displays are ‘chainable’ – connect one output to the next input – but our Arduino example code does not support this (yet). It requires a high speed processor and more RAM than the Arduino has!
Comes with: a single 32×32 RGB panel, two IDC cables, a power cable, 4 mounting screws and mini-magnets (it appears these are often mounted on a magnetic base)
Keep in mind that these displays are designed to be driven by FPGAs or other high speed processors: they do not have built in PWM control of any kind. Instead, you’re supposed to redraw the screen over and over to ‘manually’ PWM the whole thing. On a 16 MHz arduino, we managed to squeeze 12-bit color (4096 colors) with 40% CPU usage but this display would really shine if driven by any FPGA, CPLD, Propeller, XMOS or other high speed multi-core controller. The good news is that the display is pre-white balanced with nice uniformity so if you turn on all the LEDs its not a particularly tinted white.
Adafruit has had paid day off for voting for our team for years, if you need help getting that going for your organization, let us know – we can share how and why we did this as well as the good results. Here are some resources for voting by mail, voting in person, and some NY resources for our NY based teams as well. If there are additional resources to add, please let us know – adafruit.com/vote
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.