Graphic Equalizer Display IC MSGEQ7

Based on this code and schematic:

The board took about 2 hours total and the software .5 hours because this guy did all the work except the MAX7219 code which I was already familiar with.

The signal source is an iPod Nano.

Well done :slight_smile:
Here's another example with the MSGEQ7

His reads a lot like mine, only better and in stereo. On my project board there is a SPDT switch to select which stereo channel to use but it doesn't do both. I only bought one chip as an add-on on another order at Sparkfun. I suppose it could be multiplexed for both channels but I didn't want to take it that far.

can’t we make it without the MAX chip?

can't we make it without the MAX chip?

You could make this exact same project without a MAX chip. Direct drive of the display would take 15 pins (you save one because there is one column you don't need to drive). Alternately, you could do it with two 75HC595 chips and use only three lines. There are other options. I just like the MAX chip - there is a convenience factor in using it.