After we came up with the Bi-color LED Matrix Driver Module kit, we have been looking around for interesting projects to work with it.
You may be interested in some of the projects we have put up at instructables using this LED Matrix kit.
Instructable to build a Arduino (SPI) 7 Bi-color LED Matrix Scrolling Text Display
Most electronics hobbyist seems to be interested in projects involving Audio Spectrum Analyzer/Visualizer at some point in time. We decided to come up with this instructable to show how an Audio Spectrum Visualizer can be built using the Bi-color LED Matrix DIY kits.
As usual, before we decided to come up with this instructable, we browsed through the existing instructables to check if there are any similar projects. There is already a handful of instructables involving Spectrum Analyzers/Visualizers but we decided to go ahead with this instructable as we will be offering something different here and hopefully someone may find it useful.
To build this project, basic electronics knowledge with electronics component soldering skill and some knowledge on using the Arduino are required.
You may view the following YouTube video to see what we are building.
We will be building a two LED Matrix tall stereo audio spectrum visualizer here driven by an Arduino Nano. We will basically be using four Bi-color (Red and Green) LED Matrix Driver Module kits from jolliFactory and two MSGEQ7 IC chips made by Mixed Signal Integration.
Two of the LED Matrix kits are for the audio left channel and another two for the audio right channel. Each of these modules uses two MAX7219 Display Driver ICs to drive a Bi-color LED Matrix. These ICs are excellent because they take a lot of work off the micro-controller and simplify the wiring and logic design.
You can find this Bi-color LED Matrix Driver Module kit from here.
This kit comes with all through-hole components and someone with basic soldering skill should be able to assemble it without much difficulty.
See the following YouTube video on how to assemble the LED Matrix Driver Module Kit:
The MSGEQ7 IC is a single channel seven band Graphic Equalizer Display Filter. By feeding an audio signal to it, it will filter out seven frequency bands centred around 63Hz, 160Hz, 400Hz, 1,000Hz, 2,500Hz, 6,250Hz, and 16,000Hz.
The seven frequencies are peak detected and multiplexed to the output to provide a DC representation of the amplitude of each band. All we need is to read these DC values with the microcontroller analog input and output the spectrum to the Bi-color LED Matrix displays.
We need two MSGEQ7 ICs here, one for the left and another for the right audio channel. The wiring connection diagram above shows how a MSGEQ7 IC is typically connected.