RGB matrix | Embedded Lab

16×32 RGB Matrix Panel Driver Shield Revision 1

Posted on September 29, 2016 by R-B 5 comments

Our RGB matrix panel driver shield for Arduino Uno has been slightly revised. The shield now also carries the DS1307 RTC chip on board along with a CR1220 coin cell battery holder on the back. It is applicable for driving popular 16×32 RGB matrix panels with HUB75 (8×2 IDC) connectors. Row and column driver circuits are already built on the back side of these matrix panel. The data and control signal pins for driving rows and columns are accessible through the HUB75 connector. It requires 12 digital I/O pins of Arduino Uno for full color control.

Revised RGB Matrix driver shield

The revised version also has a slide switch (SW1) to select the source of the 5V input to the Arduino Uno. If it is in ON position, the 5V input from the DC barrel jack of the shield also goes to the VIN pin of Arduino Uno. In this case, Arduino Uno does not need to be powered separately as it gets from the shield. If the switch is in OFF position, the Arduino Uno must need its own power supply, which could be from an USB port or an extra DC wall adapter connected to the Uno board.

CR1220 coin cell battery holder for RTC chip

We sell the display module, the RGB driver shield, and connecting wires as a kit at our Tindie Store. Outside the United States, you can also purchase it from our Elecrow Store. The DS1307 RTC chip’s I2C bus is pre-wired to the Arduino A4 and A5 pins on the shield. This display module is fully compatible with Adafruit’s RGBMatrixPanel Library.

RGB panel and driver shield kit for only $32.99 at our Tindie store

RTC demo

Buy it here in Unites States

Buy from our Elecrow Store in China

Hookup guide and demo program for this kit

Note that the power supply required to power the LED panel is not included in the kit. You will need a regulated 5V DC power supply with enough current sourcing capability (~2A) to power the RGB panel. More details on the external power supply can be found in the hookup guide (link provided above).

RGB audio visualizer using FPGA

Posted on September 23, 2016 by R-B Leave a comment

Sam Miller, Sahil Gupta, and Mashrur Mohiuddin built a 64×64 RGB LED matrix audio visualizer as their final project for the ECE5760 Microcontroller Design course at Cornell. The visualizer responds to a musical input in real time with a graphic animation on the RGB panel using vertical bars, balls, and particle to enhance the user’s listening experience. The RGB visualizer runs off of an Altera DE2-115 FPGA, which handles all the controls and processing of data for the 64×64 LED Matrix as well as the beat detection and audio output.

Functional block diagram of RGB visualizer

Our system starts with a musical input from the 3.5mm line-in input from the FPGA. This analog input is fed through an ADC to digitize the signal at a sampling rate of 48kHz. This signal is fed back through a DAC to the line-out port into speakers in order to play the audio. After the ADC, the audio signal is separated into its frequency components through our FFT module. These frequency components are used in a beat detection algorithm to detect large changes in signal energy, which correspond to beats in the song. The bars mode of the visualizer uses the frequency components directly, while the ball and the particle mode only use the beat of the song. Each of these 3 modules uses their inputs to calculate the coordinates and corresponding colors of each LED in the matrix. The outputs of the modules are muxed and written to two buffers (since the matrix writes to two LEDs simultaneously). From here, another module reads the contents of the buffer, and drives the LED matrix via the GPIO pins on the FPGA.