I'm somehow fiend of the LED bar (or VFD) based VU meters. If it contains more elements it is better. Sometime in my youth (What? I'm still jung!!!) I wanted to build one, I bought a fist of LEDs for it, but it remained a dream. At that time the audio equipments had something like that. For today it is out of stile.
I know exactly that the "thing" has no usage value. But I want one. If I start to build something like that I want an MCU in it and not a bunch of analog circuity.
I think, pick 50pcs LEDs/side and in multiplexed mode connecting to the MCU. I pick the ADC of the MCU and after some rework display the ADC output on the LEDs.
I also need some analog front-end for this.
I guessed that not myself the only fool who want one as a separate equipment or part of something. If I create this, I'll sell it also.
The type of the MCU is not decided yet (or maybe, just I wont tell it to you).
The LEDs are an other question. On the PCB I'd like to have place for three different kind of LEDs:
1. Bargraph. The Kingbright manufactures sutch thing:
This is one option but the price is a high. Based on the color and intensity the prices are around $1-$1.5 for the 10 element bar. The full component cost will be above $15.
2. Separate reactangle shaped LEDs
This can be bought around $0.03 a piece.
3. SMD LEDs
The price is the same, but who want to handsolder them???
The idea is to create a PCB what is able to accommodate the all three types (or at least two).