by Dooievriend @ tweakblog.tweakblogs.net:
More than a year ago, a friend of mine asked me to write the software for his 3D Spectrum Analyser (3DSA): a device that takes as input an audio signal, and outputs its visualisation on a 3D matrix of leds. If the above description doesn’t quite ring a bell, simply watch the end result in action.
First things first though, the microprocessor to be programmed was an 80MHz Olimex PIC32, soldered to the PIC32-PINGUINO-OTG development board. (For those who ever tinkered with Arduino boards: it’s the same, only with a faster chip and fewer builtin libraries ) The Algorithm had to sample the input signal at regular time intervals, convert this signal to the frequency domain, and visualize the detected frequencies on a 16x16x5 LED matrix.
3D Spectrum Analyser – [Link]
by SteveQuinn @ instructables.com:
For those of you who remember the eighties, this will no doubt bring back fond memories when every piece of audio equipment in the known universe was at the time equipped with a plethora of LEDs.
More specifically the ubiquitous Graphic Equaliser or ‘Graphic EQ’.
This Instructable is centred around the MSGEQ7 to create a simple 2 Channel Graphic EQ and documents my first, poor attempt at using the Arduino Uno R3, the Arduino development environment and coding in ‘C’ for well over a decade.
LED Graphic Equaliser from the 80s – [Link]
by Phil Townshend @ edutek.ltd.uk :
A nifty 32×7 dot matrix display module, programmable via an RS232 serial port. There are preset inputs to display preset messages or simply control directly from a PC or laptop.
The principle of the display is based on our persistance of vision, the same thing that enables us to watch movies without seeing the flickering changes of frame. This display has 32 LEDs horizontally by 7 vertically. At any one time there is only ever one column of LEDs lit. The on’s and off’s are presented to the anode connections while the columns are enabled one by one. In this way a dot display of characters can be generated and when the speed is increased sufficiently, we stop seeing the flickering and see it as a steady display of dots.
LED Dot Matrix Display – [Link]
My son got one of these Leap Frog toys a few years ago as a gift. He enjoys playing with it very much. I am not sure how much counting and learning he is doing but it makes funny noises and sings to him so its a lot of fun.
Recently the unthinkable happened. It died. Not the batteries but something else. I took the back off to look at what might be wrong (which was very easy for a toy). Unfortunately, other than the speaker, a switch, battery compartment, and a ribbon cable to the front, there wasn’t much to investigate. A couple of glop tops and nothing else. I fiddled a bit more with it but everything “external” seemed fine.
Make a Custom Membrane Keypad for Arduino – [Link]
by Jan_Henrik @ instructables.com:
Hi, in this Instructable I want to show you how to create your own diffusor for a LED Matrix. To do this we will use a 3D printer and OpenSCAD. In this tutorial I will use a LOL-Shield by Jimmie ( http://jimmieprodgers.com/kits/lolshield/ ) also I will explain, how to design a diffusor for different matrix sizes and shapes.
As I recently was at the 31C3 in Hamburg i got a LOL-Shield from Jimmie. This shield is holding 126 LED´s which are Charlieplexed. After coding some animations and a game on it I thought that the LED´s where too bright. Because I wanted to keep the greyscale ( dimming ) of the matrix I decided to design and build a diffusor.
How to make a diffusor for your LED Matrix – [Link]
LED matrices are a popular mean of displaying text, graphics, and animated information at gas stations, convenient stores, and many other public places. Raj’s new project is about making a Bluetooth-enabled 8×64 LED matrix display, where you can send the text messages through a smartphone over a Bluetooth connection. He used Arduino as the main controller and an HC-06 Bluetooth adapter to receive data from the smartphone. He has shared all of his design files and Arduino firmware on his blog.
DIY LED Matrix Display with Bluetooth support – [Link]
Pup05 shared his SmartMatrix project. He writes:
The panel fits perfectly, just had to shim it with a little bit of folded card stock on each side. There’s plenty of room for the Teensy and SmartMatrix board, wiring, SD card, etc. I cut out a piece of white printer paper to size, and placed it between the panel and the glass for a bit of diffusion. The magnetic feet that came with my panel from Adafruit fit perfectly, and keep the panel pushed against the paper and glass. I cut a notch in the bottom of the back, just big enough for the power cord, USB cable, and IR receiver.
I loaded up Craig’s LightAppliance sketch and made a few minor modifications, loaded up my SD card with the animated GIFs I wanted, and everything works great. Unfortunately, I already had my Teensy soldered on to the SmartMatrix board, and didn’t feel like pulling it off to solder the RTC crystal on to the back. I might do that later, and add the temperature sensor.
SmartMatrix project – [Link]
ElecFreaks @ elecfreaks.com writes:
We were just wondering in the current market where capacitive touch screens, resistive touch screens, TFT displays are flooding, DIY enthusiasts have been rarely used dot matrix screens. Here we use 5mm 8 * 8 dot matrix screen and phototransistor to achieve a pen write function. Sounds fun? But how to specifically make it? Can we achieve a larger area pen write?
Dot Matrix Pen Write Screen – [Link]
jollifactory @ instructables.com writes:
One of the electronics DIY kit jolliFactory came up with is the Bi-color LED Matrix Driver Module Kit. This module is designed to be chain-able so that you may daisy-chain the modules together to the number of modules you need to suit your project.
Arduino Tetris on bi-color LED matrix – [Link]
by praveen @ circuitstoday.com:
Digital code lock or digital combination lock are a type of digital locks where a combination of digits/characters or both are used for unlocking the lock. This article is about a simple digital code lock using arduino. Here the code consists of a combination of digits from 1 to 6. There are separate keys for locking and unlocking the system. The system can be unlocked by pressing the unlock button after entering the correct combination of digits. A hex key pad is used as the input device. Only the first two rows of key (1, 2, 3, A, 4, 5, 6, B) are used in this project. A is used for locking the system and B is used for unlocking the system. Read this article Interfacing hex keypad to arduino for knowing more about hex keypad and its interfacing to the arduino. The circuit diagram of the digital code lock using arduino is shown in the figure below.
Simple digital code lock using arduino – [Link]