Building the FV-1 Sandbox pedal

2025-11-10T17:08:32Z

Frank: Created page with "All the files needed to build the pedal are available on the github page at [https://github.com/DisasterAreaDesigns/Sandbox-FV1 Github Sandbox-FV1] Here you will find the firmware for the RP2040-zero, gerber files for the PCBs, Eagle files for the schematics and PCBs, the assembler files, etc."

All the files needed to build the pedal are available on the github page at [https://github.com/DisasterAreaDesigns/Sandbox-FV1 Github Sandbox-FV1]

Here you will find the firmware for the RP2040-zero, gerber files for the PCBs, Eagle files for the schematics and PCBs, the assembler files, etc.

Main Page

2025-11-10T17:03:36Z

Frank: /* Getting started */

<strong>Welcome to Sandbox Pedal!</strong>

Knowledge Base for DSP Guitar Pedal DIY.

What is Sandbox? It's an open-source hardware and software package that allows for digital pedal DIY. It uses the Spin Semiconductor FV-1 digital signal processing (DSP) integrated circuit and an off-the-shelf RP2040 microcontroller board, and presents the user with the simplest possible way to get started.

# Write your signal processing code or find some cool code from another user.
# Use our code editor to assemble into a HEX file.
# Drag the HEX file into the Sandbox FV-1 pedal.
# Play.

No drivers to install. No operating system requirements. No need to be tied to any particular hardware. If you don't want to buy anything from us, that's okay - we made it all free anyway.

The bare minimum thing you'll need is an RP2040 board like a RP2040-Zero or Raspberry Pi Pico. These are open-source microcontrollers with a USB port and lots of pins you can use to interface with the outside world. Connect it to your computer, drag our firmware into the board, then hook up a couple of wires to the EEPROM in your pedal. Drag a HEX file into the RP2040 and the EEPROM will program automatically. You don't need any drivers, no software, nothing but the normal file explorer / Finder / file manager application on your computer.

Why do we need this? Honestly, we don't. There are plenty of other ways to get started with DSP, including several other FV-1 based projects. Go ahead and try some of them out.

[https://www.pedalpcb.com/product/fv1dev/ PedalPCB FV-1 DEV]

* Requires building a PCB including two 28-pin surface-mount ICs.
* Requires command-line tools for Mac / Linux.
* Programming software needs .BIN files instead of native FV-1 HEX.
* Works best on Windows but limited / basic Mac / Linux support.
* Requires at least two applications to work (FV-1 assembler or SpinCAD and AsProgrammer or CLI tools)
* Base hardware is mono in and out

Okay, I see you're back! How was that experience? A little cryptic, maybe? You need to install some drivers, or maybe update your Python install, something like that? Then you need to build a pedal from a kit and maybe that doesn't work first time, sure, we get it.

We're trying to remove as much friction as possible, and that starts with good tools. Ask your granddad about good tools vs. cheap tools and you'll probably hear something like "buy it nice or buy it twice," and that definitely agrees with our findings.

Making a chorus algorithm isn't harder than swapping diodes in a Tube Screamer, but the current state of the industry makes it ''seem'' a lot more difficult''.'' Starting DSP isn't hard, but there are a lot of steps and every single one of them has a path to failure.

The traditional way of getting started with FV-1 was to buy the official development board (US$120) from Spin Semiconductor, then use their SpinASM IDE program on a Windows computer to develop and deploy your algorithms. The dev board has RCA inputs and isn't particularly guitar-friendly, so you really need some extra hardware to get something that's closer to a real pedal.

Once you have your algorithms, you need to burn them to an EEPROM for use with an actual pedal. You can use the dev board to program EEPROMS but it's a bit clunky and you need the IDE to use it. It's fine for one pedal but if you wanted to make 50 or 100 a standalone EEPROM programmer makes more sense.

== Getting started ==
* [[Building the FV-1 Sandbox pedal]]
* [https://fv1.sandboxpedal.com FV-1 Sandbox Pedal Editor]
* [https://fxcore.sandboxpedal.com FXCore Sandbox Pedal Editor]
* [[Troubleshooting]]

Sandbox Pedal Wiki - User contributions [en]

Building the FV-1 Sandbox pedal

Main Page