Triggers are sometimes missed on kivu12 board

[ohmtech-rdi]

Description

When using a GateIn as a trigger, sometimes triggers are missed with the board kivu12.

Analysis

This depends on the width of the trigger. The way Buttons and GateIn are handled is using a multiplexer, and for now, on each buffer, just one signal is read. This is most likely OK for Button as this implies a 8ms latency, and an edge detect of 8x7=56ms, but is problematic for GateIn when the trigger signal length is less than 8ms, which is quite usual.

Workaround

Decrease the erb_BUFFER_SIZE. At 8 samples, this allows triggers as short as 2ms to be read.

• This workaround depends on the fix of issue #449

Proper fix

~~Pots are read using libDaisy using a mechanism that cycles the multiplexer faster, and outside of the software scope. The same method should be used when reading gates with a multiplexer.~~

A shift register like the one used on the Daisy Field is typically what we would want to use.