r/ValetonGP2OO

Ongoing project reverse-engineering the Valeton GP-200 (NXP i.MX RT1062, Cortex-M7). The last public release had a single mod in it. This one has eight, and it covers the LT as well as the full-size pedal.

At the end of the tuner post I said the LT was a different product with different firmware, that I did not own one, and that I would like to hear from anyone who did. People turned up. I traced the LT support in this release against Valeton's own LT image, and then LT owners proved it on their pedals rather than me on mine. That is a weaker standard than I have held the GP-200 mods to, and you should know which one your build got.

Those people put unreleased firmware on pedals they paid for. When I asked how they wanted to be credited, not one of them asked for it and several told me not to bother, so there is no list of names here. They are the reason the LT is in this release at all.

What you can tick:

• Tuner. Stock lets a note sit a full 5 cents off and still show solid green. This tightens that to 1.5 cents, mirrors tuning state onto the footswitch LEDs, and adds an optional strobe display.
• Carry-over tap tempo. A Global Settings toggle makes a tapped tempo follow you across patches instead of resetting. It never rewrites your patches.
• Footswitch labels. A/B/C/D show the name of the patch they switch to, and CTRL 1-8 show the block they toggle.
• Fast patch change. The fade-in after a patch load drops from 113 ms to 9 ms. It is still a ramp, so it still suppresses the switching click.
• Global output balance. A cut-only left/right balance on the main outputs. USB recording is untouched.
• Language unlock. Restores the full language list on units that shipped with it restricted.
• Brazilian Portuguese. Replaces the pedal's built-in Spanish menus in place. No other language changes.
• Factory-reset cleanup. A reset now clears mod settings too.

The mechanics are unchanged. It is one self-contained HTML file that you open from your downloads folder, with no server and no network calls. It works out which pedal you have from the SHA-256 of the firmware file you load, so it cannot hand you a GP-200 build off an LT image or the other way round.

One thing did change. Previous releases produced exactly one file with one known-good name, and the README told you to check for it. With eight mods to pick from that check means nothing, because every combination produces a different file. So the file is now named after the first eight characters of its own SHA-256, and the page prints the full fingerprint when it builds. The file checks against itself.

The GP-200JR is still unsupported. It has its own firmware, nothing here has been built for it, and the patcher refuses a JR image rather than guess. If you have one please get in touch.

There is a companion post going up at the same time. Two of these mods, the output balance and the carry-over tap tempo, have to hold a setting across a power cycle, and the GP-200 has no separate place set aside for that. Where a setting can actually live turned into the more interesting half of the writeup: https://gp200-reversing.hashnode.dev/eight-mods-and-how-the-pedal-saves-your-settings

Patcher: https://github.com/tntexplosivesltd/gp200-patcher/releases/tag/v1.0

Previous posts: Post 1, Post 2, Post 3, Post 4, Post 5, Post 6, Post 7

I have 1.8 and higher app and firmware versions, but I keep getting this error. How can I fix it?

Maybe I am just old, but I find the button labels to be hard to read on the GP-200. Especially the effects buttons when they are unlit, so I designed and 3D Printed this plate that simply sits on top

Link:
https://makerworld.com/en/models/3386358-valeton-gp-200-button-and-dial-label