I Have an Arduino Uno running a MSGEQ7 and a LCD. It is sampling each frequency twice for 14 samples each channel. The MSGEQ7 control pins are connected to D2 and D3.
Here is a video of it working.
Here it is simulating an analog meter.
I added a 4052 analog mux to the MSGEQ7's to get 28 frequencies per channel.
This is the same setup with a sweep generator.
Here is a video with a stereo analog meter.