I came across Analogue Research’s Artificial Neural Network last year, and have been wanting to re-create some of the submodules in Audulus ever since. The Audulus Library already includes modules for the various logic gates, but there was something in the addition of thresholds to the Boolean on and off that intrigued me. ARC provides a nice explanation of the biological model on which the Threshold Logic Neuron is based, in their video and manual.
In his video on the Compare2 DivKid covers some of the possibilities of creating rhythms with the help of logic gates and I thought I try out some similar things with the ARC logic Neuron. What I like about the thresholds is that one can shift between different logic gate types simply by changing the thresholds, either on the inputs, or the trigger threshold, and that makes it easy the add rhythmic variation with a little modulation.
As DivKid covers in the last section of his video on the Joranalogue Compare 2 dual window comparator, there’s a lot of fun to be had in the combination of knobs and logic. Robert Syrett posted that video in connection with the uWindow module he based on the Compare 2, and, since it’s a little different to the comparator, I thought it would be worthwhile for myself to also go through the steps of putting together a Schmitt Trigger.
A further detail on Schmitt triggers: Reading in the Wikipedia article that “a Schmitt trigger can be converted into a latch and a latch can be converted into a Schmitt trigger” made me realize that the ARC Threshold Logic Neuron could be used as a Schmitt trigger. The ‘single-bit’ configuration allows for the threshold and memory properties to be incorporated in one element, as in some of the analogue circuits, rather than separating them into distinct elements as with a flip-flop or sample and hold.