I made a visually different version of the 10 channel 100 Led Spectrum Analyzer circuit that I used in the 2.1 sound system. The filter quality of the Led Spectrum Analyzer is around 6, and the middle frequencies are 31Hz, 62Hz, 125Hz, 250Hz, 500Hz, 1kHz, 2kHz, 4kHz, 8kHz and 16kHz. J5 on the circuit changes the display style, you can choose to work in the form of a classic vu-meter and bar.
J4 is used to toggle the maximum amplitude value (peak hold). This Spectrum Analyzer project, in my opinion, is one of the most successful works of its period in hardware and software.
The analog part with TL071 opamp at the audio input amplifies the audio signal and prevents clipping, giving a raw audio signal at the ADC input. The entire process of determining the signal spectrum is done by the ATmega8 microcontroller. transferred to the processor.
Spectrum Analyzer circuit has ATmega8 microcontroller Bascom-Avr source software and hex files. There are two versions of the software, 2dB and 3dB, I tried both and could not see any difference. PCB file that I edited ATmega8 fuse settings, single-layer version, bill of materials, panel CNC drawings, all files are in the archive.
With normal leds, you can operate the circuit directly by using the 7805 regulator integrated with heatsink, as I did, if you want to use high-current leds, you should use a DC DC step-down module.
FILE DOWNLOAD LINK LIST (in TXT format): 28246a.zippass: 320volt.com
– filter center frequencies: 31Hz, 62Hz, 125Hz, 250Hz, 500Hz, 1kHz, 2kHz, 4kHz, 8kHz and 16kHz
– the amplitude of the signal causing the next LEDs in the bar to light up: from -16dB to + 2dB with a 2dB step
– 0dB indication corresponds to the input signal with an amplitude of 0.2V
– work in the mode of displaying bars or points
– maximum amplitude display mode
– presenting the spectrum on the field with multi-colored LEDs (100 LEDs !!)
– 12V DC power supply