Knight dash project.

[JKnightandKARR]

That's another reason I did one with an Arduino Uno... not the best display, but i saw the 3914 think been discontinued, think i got 3915.. if have another option I am all ears!

Here's my attempt... responce is VERY bad...

[Chris Savage]

December is the busiest month for me as far as holidays, birthdays, events, etc, not to mention still working on the new house. But I'm planning on getting content updated after the holidays (New Years). One of the things that should be quick and easy is to redraw the schematic for the Audio Level Meters. I am making a priority list so I can maximize my time and wrap things that only need new photos or minimal updates. Perhaps that schematic will be of use to you in the future.

[JKnightandKARR]

Ok, I been doing research on other options myself, inc thinking about trying to translate my arduino code onto the propeller and see if I can make it work better on there.

Edit:  I think maybe the code I used on Arduino might have been the issue.. I was trying to find the code, must have lost it somehow..., random opening example to locate the ext to search for, and they already have a bargraph example, which I'll try and see if that works any better, esp with the buffer circuit you mentioned.

[Chris Savage]

random opening example to locate the ext to search for, and they already have a bargraph example, which I'll try and see if that works any better, esp with the buffer circuit you mentioned.

The circuit / buffer I mentioned is more or less a poor-man's "peak hold" for VU meters. Let me explain...

Since the audio signal is an AC waveform, the default level meter circuit is very jittery as the waveform jumps very quickly from its peak value to zero (or negative in many cases). The circuit I created rectifies (using a single 1N914 diode) the audio to grab only the positive portion of the AC signal, then uses a 0.1µF capacitor and 1MΩ resistor to "buffer" that signal, causing it to "hold" longer. The effect is that the VU meters are more fluid and responsive. If you're doing this on an audio switcher or pre-amp, you would want to use an op-amp to buffer / isolate the source audio and you may want to provide an adjustment to calibrate the signal for peak reading on the meters.

[JKnightandKARR]

Thanks Chris. I planned on an adjustment already.  That might be why my video is bad on performance/the program I used could have been an issue too... I will try the program in the Arduino library, that should fix any issue with that, and will try your circuit too.