Arduino MIDI synthesizer (Part 3) - ADSR envelope

This part explains how ADSR envelopes work. Unfortunately we hit the limits of the gcc optimizer and and the performance issues force us to go down to 11kHz sampling rate :(
This means no further features like LFO etc until we switch to assembler but then just few would be able to follow. Sorry folks.
Source code can be found here:
You might also want to read about (it's used to calculate the ramps):
Basic infos about synthesizer can be found here:

[Taras]

Wew! It's so awesome seeing your videos 9 years later. Surely shows how much you've grown since then

[jamiemascola]

Very cool, bitluni!

I'm surprised at how far you were able to get that much happening with an eight-bit Atmel chip! You could always try out something with an ARM Cortex M4f (many dev kits are less than $20 nowadays), or byte the bullet and go real time with a FPGA. I did a project back in my student days where I used an eight-bit MCU to handle all of the MIDI messaging and dynamic processing, and used a CPLD as my tone generator. It balanced the workload really nicely. Verilog and VHDL certainly aren't my favorite thing in the world to code, but CPLDs and FPGAs are just so good at real time signal control.

[dbingamon]

Why not use multiple Arduino (Atmel) chips to handle additional channels?
Very much enjoyed it.

[fabriziobandiera]

Is it possible to have it in eurorack format ? Thank You for Your explainations ! Cheers !

[nickpelov]

how about a simple 20 kHz (or lower) analog filter to make it less distorted. Maybe 11 kHz will sound a bit better.

[ecohostel]

my friend, colleague you work, tutorial is perfect. thank you ;)

[BritishBeachcomber]

You really need a log/exp curve for attack, decay and release.

[hangebicom]

It is quite interesting experiments, I'm not familar with arduino, but I'm doing similar experiments using PIC12F1840 controller, and using hardware PWM generator for sound synthesis. Maybe you should go this way with arduino too?

[shinevisionsv]

Hahaha, it sounds so sad when you go over the max amount of keys it can handle. awesome video tho!

[leoportopassos]

Hello! Do you know of any device or software with which I can analyze the ADSR of an electric guitar?

[Realsynex]

have you looked at using the Arduino Due? 
A 32-bit core, that allows operations on 4 bytes wide data within a single CPU clock.
84 MHz Clock
Same form factor as the Mega.
Just a thought. :)

[woofcaptain]

I personally think the lower sample rate creates a nice bit crushed effect. Of course you might not want that I guess lol.

[sparkc]

it think this project is use full for chip tune synth since it Ardunio is micro controller and not sound card.