The GMSN! Pure ADSR module is used to create CV envelope, which can be patched into other eurorack modules to control pitch, filter cutoff and volume. These are either triggered externally or manually via the trigger button.
There are three envelope modes to choose from:
ADSR - Once triggered the envelope goes through all 4 stages: Attack, Decay, Sustain & Release
AR - The envelope will go straight into the Release phase as soon as Attack is completed. Great for drum synthesis
Trap Mode - This is a looping trapezoidal envelope with 4 stages: Attack, On, Release, Off. This can be retriggered externally or via the trigger button and can be used to create looping LFO shapes.
The design is based on the same chip used in the Arduino Uno, which means the same code, libraries and IDE can be used. Check out the GMSN! Youtube video for how to upload the code onto the module.