Ok, now that we’re introduced to the Arduino workflow (see Project Effects Loop Switcher PART 4: ‘Hello Arduino’…) it’s time to start thinking of how exactly we want our loop switcher to behave.
Behaviour
Let’s first define what features we would like for our switcher and how they would translate into the final result.
3 main features can be distinguished:
- A user can select a preset by pressing a specific button (footswitch). A preset defines which loops are in the signal chain. Pressing the button of an active preset disables that preset, taking all of the loops out of the signal chain.
- A user can edit a preset: loops can be added or removed from the signal chain when the switcher is is some kind of edit-mode.
- A changed preset is stored, even after the unit has been turned off.
The video below shows the result of what is described in this post and illustrates the features that are described above.
Note: for practical reasons the number of buttons, presets and loops are limited to 4 of each.
How to use it
The buttons (on the right) represent 4 footswitches.
The green LED’s represent the presets. LED on means preset is active. Only one preset can be active at a time.
The red LED’s represent the loops that are engaged.
Initially each preset is clean, none have any loops engaged. Pressing a button will engage the corresponding preset (while disengaging another, if active). Pressing it again will disengage it.
To enter edit mode I added a long press detection to the far left button. If this button is held for 2 seconds, the blue LED will light up, indicating that we are now in edit mode.
While in edit-mode the buttons are no longer used to change presets (green LED’s), but instead they engage specific loops (red LED’s) for the active preset.
Pressing the far left button again for 2 seconds will exit edit mode. Now we have stored which loops are engaged for the active preset.
This configuration also makes it possible to use our pedal switcher in 2 ways:
- You can use it as a preset selector, to avoid tap-dancing while playing
- When you leave edit mode on all the time, you can use it as a standard looper (e.g. to achieve true bypass for all your effect pedals that need it)
Now that we’ve cleared all this out I will show you how we can build a prototype (using the Arduino starter kit) and how we could translate these features into code. (Coming very soon)