Ava Micek’s Work Log

Project Update 1 (9/13/2024):

Attached below is a sketch of what the Delay pedal that me and Xavier will be contributing to the pedalboard might look like. Currently, we have two main ideas of alterations to the typical delay design to improve utility to Viola players: EQ on delay repeats, and delay sample length cutting. My drawing below shows a control configuration for a fairly typical delay pedal, with the notable addition of a switch for a delay sample length cut.

To Do List:

• Work with Georgia to record a Viola test track for preliminary testing of existing Delay/Reverb pedals.
• Meet with Dr. Pinar to assess what aspects of his multi-fx pedal project could be utilized for the Pedalboard.
• If a hardware platform is confirmed in meeting, begin coding the delay effect/making block diagram of how delay effect will work/interface with hardware.
• If a hardware platform unknown after meeting, research and decide on microcontroller platform and add-ons to use for pedal.
• Create presentation slides for Thursday meeting.

Concerns:

My primary concern going into next week is how much of Dr. Pinar’s project will be useful for our purposes. The meeting will be on Monday morning, so we will have a full workweek to apply what we learn from him, but the anticipation is killing me.

Project Update 2 (9/22/2024):

Last week was big for the project! Dr. Pinar met with us on Monday, and subsequently gave us the Raspberry Pi 4b with a HifiBerry ADC+DAC hat! Before we could get working on it, the team met again to write our project presentation for the weekly OSHE meeting. After our presentation, we then worked together to revisit and revise our project spec so that our goals and and evaluation criteria would better align with the new direction of our project: A Multi-FX pedal! Finally, we all met again over the weekend to get Elk OS booted and configured with our hardware and dig through documentation to see what we would have to do next to get our hardware usable with audio plugins. We also began brainstorming ideas for user input with the device, with the implementation of a combined LCD and potentiometer module being our main idea. My To Do list for last week was a bit too ambitious in scope, so I’ll be dialing it back a bit for this week to focus on more concise, actionable items. Our next big step with the hardware is to learn how to actually use it with a VST3 plugin, which will most likely be the plugin type we write for use the pedal in the future.

To Do List:

GOAL: Use a VST3 plugin with the Pi to apply an effect to a guitar signal.

1. Choose a VST3 plugin to test the Pi with
2. Identify how to configure plugins to run as analog in-analog out with the Pi
3. Load plugin onto Pi
4. Test the system with a guitar input and output to a guitar amplifier

Concerns:

I think that our user interface on the pedal is going to be very technically challenging to develop, likely moreso than designing our plugins. As we start to get a better grasp for how Elk OS works, we need to pay special attention to see how we need to approach the potentiometer control and LCD display.

Project Update 3 (9/29/2024):

The operation of the bulk of the device will be done through the use of a rotary encoder/pushbutton. The user will be able to cycle through the effect parameters, back button, and on/off control by turning the rotary encoder, with a color change indicating what item is being targeted. The user can then press the button in the rotary encoder to select the item. If an effect parameter is selected, the user can adjust the parameter value between 0 and 99, and then press the button again to return to item selection. When selected, the on/off control will toggle the effect between on and off when the button is pressed. When the button is pressed while the back button is selected, the user will be able to select what effect to open controls for from the header. When an effect is selected from the header and the button is pressed, the line at the bottom of the header under the selected effect will disappear and the user will return to the selection of effect parameters, etc. The footswitch will toggle the pedal between actively effecting the guitar signal and bypassing the pedal effects.

This week, I helped in finding a screen and rotary encoder to use for the project and designed a GUI layout for the pedal’s screen. I succeeded in finding and learning how to load a VST3 plugin onto the Pi, but was unable to get the plugin to run properly by the end of the week. I have learned that we will need to write a config file for each plugin to set the device parameters while the plugin is active, and began writing a config file for the selected VST3 plugin. My main personal goals for next week will be centered around learning how to write config files for the VST3 plugins we will design, as well as creating step-by-step documentation and a template file for future use.

To Do List:

GOAL: Create VST3 config file, config file template, and config file documentation.

1. Write config file for VST3 plugin
2. Verify operation of plugin on hardware
3. Create step-by-step instructions for config file setup
4. Create config file template

Concerns:

We need to get parts ordered early this week to begin working on user controls, we got considerably hung up on finding an appropriate screen to use last week.