New FV-1 Pedal - Easy Spin

[taudio]

We've been working on an updated FV-1 pedal with a USB programmer and software for the past few months and we're finally ready to share it.

Easy Spin is easy to build and easy to program with our USB programmer and free (open source) fv1-programmer software that features crazy fast EEPROM burning, integrated assembly / disassembly (thanks to asfv1 and disfv1), along with a number of other awesome features. See https://audiofab.com/downloads for information on the USB programmer.

Easy Spin leverages earlier (and great) work done by Ice-9, HexeFX and others to provide an easy to assemble, high quality FV-1 pedal. We've re-designed the power supply using a low noise, LDO regulator and added inductive filtering on the DSP to further reduce noise. This, along with a two-layer PCB with significant ground planes, delivers an ultra low noise pedal. Everything except the 9V battery clip and the programming jack assemble onto a PCB, meaning there is almost no off-board wiring needed.

A plug-in switch board supports all eight programming slots but also makes it easy to alter the pedal to support fewer programming slots via simple hardware modifications such as using a jumper for one program or a three-position toggle switch for three programs.

Schematics for the DSP PCB and Switch PCB are included below. Full, step-by-step assembly instructions are available on our website. We also provide test programs and some additional effects banks made using SpinCAD -- the incredible tool from Digital Larry.

Raw PCBs are available, as well as the PCBs with preassembled surface mount components. We also offer fully assembled pedals.

We hope this contribution will help inspire others to make amazing DIY DSP effects and give back to the community.

DSP Board Schematic



Switch Board Schematic

[mark2]

That looks like a really great project! I can't wait to dive deeper and get a closer look.

A couple of initial questions out of curiosity:

* Is there a particular reason for, or problem the CMOS is solving compared to a bunch of diodes, e.g. the way the PedalPCB arachnid does it? Not that there needs to be of course.

* Is the programming cable using a custom uC? Or is there some kind of off-the-shelf USB to I2C solution?

[taudio]

Thanks! We were inspired by all of the amazing work from this forum.

We chose a CMOS device for the switch because space was limited and assembling one IC seemed easier than a bunch of SMT diodes. Diodes would work fine if you can make it work mechanically.

The programmer uses an off-the-shelf USB to I2C converter based on the MCP2221A.

That looks like a really great project! I can't wait to dive deeper and get a closer look.

A couple of initial questions out of curiosity:

* Is there a particular reason for, or problem the CMOS is solving compared to a bunch of diodes, e.g. the way the PedalPCB arachnid does it? Not that there needs to be of course.

* Is the programming cable using a custom uC? Or is there some kind of off-the-shelf USB to I2C solution?

[Ice-9]

Nice to see development of the FV-1 still going strong. The addition of the USB programmer is a good addition.

[taudio]

Thanks Mick!

The FV-1 pedal you posted in this forum was the main inspiration for our work.

[taudio]

We've just posted three tutorial videos on YouTube that cover the setup and programming of the Easy Spin pedal:

FV-1 Programmer Installation

Easy Spin Software Setup

Easy Spin Programming

For getting started with DSP effects development, Gary Worsham's (aka Digital Larry) YouTube channel has some great information on SpinCAD Designer. See here.

Another great resource is the SpinCAD Designer Gitbook.

Enjoy!

[Thornpar96]

Thank you for sharing useful information.

[taudio]

We've just released an update to the FV-1 programmer -- we now have standalone executables for Windows, Mac and Linux.

Here's an installation video (on Windows): https://youtu.be/N2w-bj4lZxs

Source code is available here: https://github.com/audiofab/fv1_programmer

Enjoy!

[Digital Larry]

I finally got around to using the software today.  I had been afraid of losing some of the really nice programs which were on the pedal when you sent it to me.  Well I shouldn't have been, because fortunately you have included a "read" function.  Once I read the instructions, I installed (on Windows this time, since everything else already set up on Windows) using pip and then ran the program.

Things I like:
- easy to install with PIP
- reading and writing is very fast compared to using PK2CMD with a PICKit 2.

Things I think could be improved:
- What is the "current" folder?  For me it was just my C:\Users\Larry folder, so everything I save is in this folder, which is a bit inconvenient.  I'm not too hot on having to set "Folders" like the Spin IDE does.  I'd rather just navigate to the folder and have the program remember the last place I was.
- After loading in the code from the EEPROM, I wished that I could name the individual program slots or add a comment at the top of the code indicating what it is.  I was able to reorganize the existing patches by doing copy-paste between slots but I had to keep track of what I was doing because I couldn't recognize the disassembled code.  Ideally, this UI would just include an editor so I could make quick code changes directly if I felt like it.
- Similarly, it would be nice to allow saving of an individual program rather than having to copy/paste it into a text editor.
- Since SpinCAD can create a SpinIDE "Project" for all 8 programs at once, it would be cool to allow loading programs this way.

Right now the Easy Spin pedal occupies the "pre-dirt modulation" slot for my amp setup.

Thanks,

DL

[taudio]

Thanks for your helpful feedback Digital Larry!

Happy to hear you are enjoying the pedal and patches.

To answer your question: the "current folder" should be the directory where you started fv1_programmer.

We'll keeping working on improvements to fv1_programmer with all of your feedback in mind.

[taudio]

We've released an updated version of our open-source FV-1 Programmer with some awesome new features like integrated text editing and named tabs. You can get it here:

https://github.com/audiofab/fv1_programmer

We also created a video that demonstrates most of the new features. See

Enjoy!

[potul]

Your programming software looks interesting.
Is there the option to use it with another programmer or will it work only with your device? (I assume MCP2221A based...)
Could it work with a generic MCP2221A breakout board?

Thanks,

Mat

[pruttelherrie]

Could it work with a generic MCP2221A breakout board?

I'm not very python-versed but reading through the code I don't see a reason why it wouldn't.

This file https://github.com/audiofab/fv1_programmer/blob/main/adaptor/mcp2221.py
calls EasyMCP2221 https://github.com/electronicayciencia/EasyMCP2221

[taudio]

Your programming software looks interesting.
Is there the option to use it with another programmer or will it work only with your device? (I assume MCP2221A based...)
Could it work with a generic MCP2221A breakout board?

Thanks,

Mat

Yes, it should work with a MCP2221A breakout board.

The programming port pinout is shown at the beginning of this thread (pedal schematic) and in the pedal assembly instructions on our website.

Good luck!

[potul]

Hi both, thanks for the info. I will give it a try next week.

[potul]

Hi taudio

I just tried your programmer software. Works like a charm, at least the limited tests I did.
I miss a couple of features though, that you might think about for future releases:

1-Saving programs to spn format. As fas as I can tell you can only save the complete pack of 8 programs to a json format.
2-Reading and saving hex files. (is the compiled file saved somewhere?)

Thanks and regards

Mat

[mark_melvin]

Hi potul,

Mark here from Audiofab. Thanks for the feedback! Glad you were able to get it working.

Regarding saving to .spn format, this is something we could consider for a future release. You're correct - the only save format at the moment is a JSON of all 8 banks. You are looking to save each tab as a separate .spn file? I guess for now you'll need to copy and paste the editor contents into another program.

There is some support for .hex files today. There is a command line option to use fv1_programmer to flash a .hex file to the EEPROM by running:

fv1_programmer --load-file <filename>

Where <filename> is a .hex file.

At the moment, there is no saving of the compiled programs when you download to the EEPROM. But you can suck the entire contents of EEPROM out and save to a binary file with the --save-file command line option, but this is not a .hex file.

Cheers,
Mark

[potul]

There is some support for .hex files today. There is a command line option to use fv1_programmer to flash a .hex file to the EEPROM by running:

fv1_programmer --load-file <filename>

Where <filename> is a .hex file.

At the moment, there is no saving of the compiled programs when you download to the EEPROM. But you can suck the entire contents of EEPROM out and save to a binary file with the --save-file command line option, but this is not a .hex file.

thanks for the ideas... Is the binary file a .bin file? Is this a format I can later on load or reprogram to the EEPROM? I'm basically looking for a way to backup/restore to the pedal without having to switch to a different programmer (today I use a PICKit to read and write hex files)

[mark_melvin]

thanks for the ideas... Is the binary file a .bin file? Is this a format I can later on load or reprogram to the EEPROM? I'm basically looking for a way to backup/restore to the pedal without having to switch to a different programmer (today I use a PICKit to read and write hex files)

Yes, exactly. It is just a dump of the EEPROM directly and fv1_programmer supports re-loading .bin files or .hex files. It keys off the file extension, so if you save it as a .bin, you can re-load it with --load-file. I will look into the complexity of saving as a .hex as well.

You can also read out all the programs with the GUI, and they will be disassembled, and then you can save that as a JSON as well. You'll lose the comments and program names, obviously, but this is also an option.

Mark

[potul]

You can also read out all the programs with the GUI,

Can I load a bin or hex file from the GUI? I didn't find this option.