PedalinoMini™

Wireless MIDI foot controller for guitarists and more.

You can change the presets of your guitar rig, turn old MIDI equipment into something that’s USB-compatible, give you hands-free or foot-occupied ways to control your rig during a live performance, and it can be done with WiFi or Bluetooth. This is a full-featured MIDI controller, with three user profiles, and it can control a maximum of 36 foot switches. That’s an impressive amount of kit for such a small device; usually you’d have to spend hundreds or even thousands of dollars for a simple MIDI controller, and the PedalinoMini does everything with very cheap hardware.

• Plug-and-play with any MIDI-compatible app on iOS 8 and above as well as OS X Yosemite and above.
• High customizable using web interface
• Bluetooth, WiFI, USB and legacy MIDI interfaces
• No extra drivers to connect Windows, macOS, iOS (iPad/iPhone) and Android
• Bluetooth LE MIDI (iOS and macOS compatible)
• Network MIDI (aka AppleMIDI or RTP-MIDI)
• ipMIDI
• Open Sound Control (OSC)
• IEEE 802.11 b/g/n Wi-Fi 2.4 GHZ with WPA/WPA2 authentication
• Bluetooth Low Energy 4.0 server or client
• DIN MIDI IN and MIDI OUT connectors
• MIDI routing
• MIDI clock master and slave
• MIDI Time Code (MTC) master and slave
• OSC to MIDI and vicecersa
• Any number of pedals of any type in any order
• Auto-sensing footswitches and expression pedals
• Trigger-to-MIDI (soon)

Features

• Support for digital foot switches (momentary or latch), analog expression pedals, jog wheels (rotary encoders) and triggers.
• 6 controllers ports for ESP32 and 8 controllers ports for ESP32S3. One controller port can support up to 6 indipendent switches for a total of 36 (ESP32) or 48 (ESP32S3) switches.
• 20 banks + 1 global bank
• 3 user profiles
• 20 sequences of 10 steps each
• Each port can connect 1 expression pedal or 1 jog wheel or up to 6 foot switches via a resitors ladder (TC HELICON Switch-6).
• MIDI output via AppleMIDI (also known as RTP-MIDI) or ipMIDI via Wi-Fi
• Send almost every MIDI messages: Program Change, Control Code, Note On/Off, Channel Pressure, Pitch Bend, Bank Select, Start, Stop, Continue or a sequence of the previous messages
• MIDI channel, MIDI note, MIDI control code, MIDI program change can be configured by each pedal and by each bank
• Switch debouncing and analog noise suppression without decreasing responsivenes
• Invert polarity via software
• Individual automatic calibration of expression pedals. Manual fine tuning is not usually requested.
• Transform a linear expression pedal into log expression pedal and vice versa
• Calibrating resistors ladder is easy as pressing footswitches in sequence
• RGB NeoPixel/WS2812B status leds
• Responsive and mobile-first configuration web interface (http://pedalino.local)
• Installing firmware and WiFi provisioning directly from your browser
• Smart Config technology to help users connect to a Wi-Fi network through simple app on a smartphone.
• OTA (Over the Air) firmware update or via HTTP (http://pedalino.local/update)

PedalinoMini™ 4

An easy way to create one is by building the PedalinoMini™ 4. I aimed to keep it as simple as possible.

PedalinoMini™ 4 operates seamlessly with its 4 footswitches, featuring a big 1.9" color display equipped with WiFi, Bluetooth, and USB MIDI capabilities. It is powered through a USB-C port, using either a power adapter or, for enhanced convenience, a compact power bank, ensuring up to 6 hours of uninterrupted functionality.

PedalinoMini™ 6/8

Do you need more footswitches? PedalinoMini™ 6 or PedalinoMini™ 8 is for you.

Sponsors

New features, bug corrections, priority reply will be offered at zero-day to sponsors only. Sponsors will have access to a private repository.

New features and bug corrections will be released to this public repository when one of the following goals is met (whichever come first):

• One thousand stars

  Add a star to the project if you don't want be a sponsor.

  Goal is 1000 stars.

• 12 months from October 25th, 2024

  Be patience if you are not ready to add a star.

  Goal is reached on Ocotber 25th, 2025.

When one of the previous goals will be reached sponsors will continue to receive in advance new versions and new goals will set.

Sponsors version additions/fixes since October 25th, 2024:

• None

PedalinoMini™ Case 1 is available to sponsors only.

Public versions history

Bill of materials

The shortest bill of materials ever: an ESP32 board and a OLED display. That's it.

• Any ESP32 board supported by Arduino core for ESP32
  • Tested on DOIT ESP32 DevKit V1 4M dual-mode Wi-Fi and Bluetooth module
• OLED I2C 0.96"/1.3" display 128x64 pixels SSD1306/SH1106 based

Not enough short?

• An all-in-one LILYGO® TTGO T-Display with an 1.14" IPS display and onboard lithium battery interface

• An all-in-one Heltec WiFi Kit 32 with an integrated OLED display (0.96") and onboard lithium battery interface

• An all-in-one TTGO T-Eight ESP32 with a bigger OLED display (1.3"), 4MB PSRAM and onboard lithium battery interface

Not enough powerful?

• BPI-Leaf-S3
• LILYGO® T-Display-S3

USB MIDI (ESP32 only) and DIN MIDI connection requires additional hardware.

Schematic

Warnings

• Do not forget the add the pullup resistors on PIN_A1 to PIN_A6 otherwise pins will be floating. A floating pin can trigger unexpected MIDI events. As alternative you can disable the not used pedals via web interface.
• GPIO12 must be LOW during boot. MTDI (GPIO12) is used as a bootstrapping pin to select output voltage of an internal regulator which powers the flash chip (VDD_SDIO). This pin has an internal pulldown so if left unconnected it will read low at reset (selecting default 3.3V operation). Connect to the corresponding controller port only pedals that can guarantee a LOW value on boot. For more details check the official documentation here.

To create your own ladder you can start simulating the below ones:

Simulate voltage ladder 2k 3k 5.1k 10k 30K

• Thinkercad
• Circuit Simulation Applet

Simulate voltage ladder 10k (TC-Helicon Switch 6)

• Thinkercad
• Circuit Simulation Applet

Simulate "D1 Robot LCD Keypad Shield" voltage ladder

• Thinkercad
• Circuit Simulation Applet

How to upload firmware, WiFi provisioning and access to web user interface

Visit http://alf45tar.github.io/PedalinoMini/installer to install public firmware, update firmware, connect device to a WiFi network and visit the device's hosted web interface.

For sponsor only visit http://alf45tar.github.io/PedalinoMini/sponsor-installer to install latest firmware, update firmware, connect device to a WiFi network and visit the device's hosted web interface. It is required a secret key available on sponsor area.

The only requirement for now is to use a Google Chrome or Microsoft Edge browser (Safari and iOS devices are not supported yet). WiFi provisioing via Bluetooth is only supported in Google Chrome on Windows.

USB MIDI using Raspberry Pi Pico (RP2040)

Raspberry Pi Pico is a generally available cost-effective board that can be used to add an USB MIDI connection.

Method 1

Thanks to Sthopeless

• Flash Pico with the .UF2 binary file provided here https://github.com/rsta2/pico/releases/tag/v1.0
• Connect ESP32 RX1 to Pico GP0 and ESP32 TX1 to Pico GP1 and GND to GND.

Method 2

• Flash Pico with CircuitPhyton .UF2 binary file provided here https://circuitpython.org/board/raspberry_pi_pico. Tutorial available here.
• Copy the CIRCUITPY folder files under the CIRCUITPY Pico drive. The CIRCUITPY folder contains the boot.py file and the Adafruit CircuitPhyton MIDI library.
• Connect ESP32 RX1 to Pico GP0 and ESP32 TX1 to Pico GP1 and GND to GND.

For both methods:

• If the Pico is powered via USB, the VSYS must NOT be connected to other power source.
• [Optional] Power ESP32 board just feeding the power from the VBUS port on the Pico to VIN (if available) of the ESP32.

IMPORTANT: ESP32 board and Pico must share GND.

USB MIDI using Arduino Pro Micro

The cheapest and compact way to implement an USB MIDI connection is using an Arduino Pro Micro and the BlokasLabs/USBMIDI library. Upload the UsbMidiConverter example into the Arduino Pro Micro.

Serial1 of ESP32 (re-mapped to pin 18 RX and 19 TX) is connected to Serial1 (pin 1 TX0 and pin 2 RX1) of Arduino Pro Micro. Use a 3.3V Pro Micro board. A 5V Pro Micro board works too because the ESP32 is usually 5V tolerant.

Arduino Pro Micro is powered by the USB MIDI connection.

IMPORTANT: ESP32 board and Arduino Pro Micro must share GND.

Booting modes

PedalinoMini™ has 8 booting modes:

The last booting mode (1-5) is selected if you don't press any button on boot.

The default boot mode is (1) Normal.

To select a different mode:

• Press and release EN button (POWER button on TTGO T-Eight) and immediately after press and hold BOOT button (CENTER button on TTGO T-Eight)
• Follow the istructions on display. Keep it pressed until the progress bar reach the end to reset to factory default. If you release the button before the progress bar reach the end PedalinoMini™ will start in one of the supported boot mode.

• (x) Supported (-) Not supported
• USB-MIDI and DIN-MIDI are always available if hardware implemented.

How to build and upload

PlatformIO is the recommended IDE for PedalinoMini™ build and upload.

1. Install PlatformIO IDE for VSCode
2. Install Git
   • On Windows, install git from https://git-scm.com/download/win
   • On macOS, install Command Line Tools for Xcode running xcode-select --install via Terminal. Remember to run the command every time you update your macOS.
3. In VSCode run the following commands:
   • from View->Command Palette (Ctrl+Shift+P)
     • Git: Clone
     • You will be asked for the URL of the remote repository (https://github.com/alf45tar/PedalinoMini) and the parent directory under which to put the local repository.
   • under PlatformIO Project Tasks select your environment (i.e. env:esp32doit-devkit-v1)
     • Click "Build" under General
     • Click "Upload" under General
     • Click “Upload File System Image” under Platform. Do not skip this step otherwise the WebUI will not works properly.

That's all folks.

Before any update save configuration, reset to factory default and reload configuration. EEPROM can change without any further advice.

How to connect PedalinoMini™ to a WiFi network

PedalinoMini™ supports IEEE 802.11 b/g/n WiFi with WPA/WPA2 authentication (only 2.4 GHz).

PedalinoMini™ support 5 WiFi provisioning methods: 1 via USB, 1 via Bluetooth and 3 via WiFi.

PedalinoMini™ is using ESP Web Tools not only to install the firmware, via USB with a click of button right from you browser, but also to connect it to WiFi with the same simplicity via USB or Bluetooth.

PedalinoMini™ also implements Wi-Fi Protected Setup (WPS) and Smart Config technology (Espressif’s ESP-TOUCH protocol). WPS needs access to the WPS button on the WiFi router. Smart Config requires a smartphone with one the following apps:

• ESP8266 SmartConfig for Android
• Espressif Esptouch for iOS

If the WiFi network is not available PedalinoMini™ will create an hotspot for you. Once connected to the PedalinoMini™ hotspot, you can use the web interface to set the SSID and password of an access point that you would like to connect to.

• On power on PedalinoMini™ will try to connect to the last know access point
• If it cannot connect to the last used access point within 15 seconds it enters into WiFi provisioning mode via USB or Bluetooth
• Visit http://alf45tar.github.io/PedalinoMini/installer and follow the instructions
• If provisioning is not finished within 60 seconds it enters into Smart Config mode (if compiled with -D SMARTCONFIG in platformio.ini)
• Start one of the suggested apps to configure SSID and password
• If it doesn't receive any SSID and password during the next 60 seconds it enters into WPS mode (if compiled with -D WPS in platformio.ini)
• Press or press and hold (it depends by your router) the WPS button on your WiFi router after PedalinoMini™ entered in WPS mode
• If it doesn't receive any SSID and password during the next 60 seconds it switch to AP mode
• In AP mode PedalinoMini™ create a WiFi network called 'Pedalino-XXXXXXXX' waiting connection from clients. The required password is XXXXXXXX (uppercase). XXXXXXXX is a variable string.
• Reboot PedalinoMini™ to restart the procedure.

Any of the previous steps can be skipped pressing BOOT button.

void wifi_connect()
{
  auto_reconnect();           // WIFI_CONNECT_TIMEOUT seconds to reconnect to last used access point
  if (!WiFi.isConnected())
    improv_config();          // IMPROV_CONFIG_TIMEOUT seconds to receive provisioning SSID and password via USB or Bluetooth and connect to WiFi
  if (!WiFi.isConnected())
    smart_config();           // SMART_CONFIG_TIMEOUT seconds to receive SmartConfig parameters and connect
  if (!WiFi.isConnected())
    wps_config();             // WPS_TIMEOUT seconds to receive WPS parameters and connect
  if (!WiFi.isConnected())
    ap_mode_start();          // switch to AP mode until next reboot
}

How to connect to the web user intertace

The responsive and mobile-first configuration web user interface is available on http://device-name.local address (the address is case insensitive). The device identification name is unique per device. Every device/board has a different device name. For example I am using http://2ab267ac.local to connect to my PedalinoMini™.

In order to know your device name and/or the IP address press for at least half a second the BOOT button and check the display.

As alternative method you can use the IP address. If you are using the AP mode the IP address is always 192.168.4.1 and the connection address is http://192.168.4.1 for everyone.

There is no credentials to connect to web user interface. Device name and credentials to connect to web user interface can be changed in the Options page.

Pedals

Once PedalinoMini™ is connected to a WiFI network and you are connected to the web user interface it is time to configure which pedal is connected to each of the 6 available ports. Pedal 7, 8 and 9 (if present) are the on board buttons and they are fully configurable.

Controls

A control is a single switch of a pedal (i.e. button 2 of pedal 4) or a combination of 2 switched of any pedal to be pressed simultaneous. Controls are used to logical sort and hide the physical connection of switches or to define a new control as simultaneous press of 2 switches.

Actions are triggered by controls. As a consequence a control is needed also for analog and ultrasonic pedals.

Due to hardware limitation simultaneous press do not works with 2 switches of the same MOMENTARY 3, LATCH 3 and LADDER. Instead simultaneous press works well between one switch of a MOMENTARY 3/LATCH 3/LADDER pedal and any other switch of a different pedal of any type. Simultaneous press works well between the 2 switches of the same MOMENTARY 2 or LADDER 2 pedal.

For each control it is possible to define the default led number to be used in Actions. It helps to simply the hardware leds connections but keeping each led logically linked to a switch.

Of course the simultaneous release, double click and long press are supported too even if they are not so usefull.

Actions

Once Controls setup is complete proceed with Actions setup to define which event (press, release, double press, long press, repeat pressed, long release, move or jog) trigger an action.

1. Select a bank on top left. Bank 0 is also called global bank. Actions added to bank 0 are active in all the others banks.
2. Select a control on top right or "All"
3. (Optional) Enter the Bank Name
4. Click on New Action and select a control on the dropdown menu.

• (-) Not used
• (+) if velocity is not zero it is equivalent to NOTE ON
• MSB is the Most Significat Byte. It is a fixed value from 0 to 127.
• LSB is the Less Significat Byte. It is the variable value from 0 to 127.

Interfaces

The supported interfaces are:

For each interface there are 4 filtering options:

Routing between different interfaces is enabled between every IN enabled interfaces to any OUT enabled interfaces. Do not confuse routing (different interfaces) with MIDI Thru (between IN and OUT of same interface).

Sequences

Options

PedalinoMini™ has a lot of options well documented in the Options page.

Configurations

The complete profile setup can be saved as configuration to be used later or just for backup reason in case of hardware failure. Configuration files can be downloaded and shared with others PedalinoMini™ users. A complete configuration file editor is provided for advanced operations.

Some example configurations are provides. The default configuration for PedalinoMini™ Case 1 is available as 'case1'.

iRig BlueBoard

PedalinoMini™ can emulate an IK Multimedia iRig Blueboard using 'blueboard' configuration. Midi Mode 1 is on bank 1 and Midi Mode 2 is on bank 2. PedalinoMini™ emulation works on any MIDI interface and not only "MIDI over Bluetooth" as the original iRig Blueboard.

Fender Mustang Amplifier

PedalinoMini™ can control a Fender Mustang I/II/III/IV Amplifier via MIDI. Additional software is required to translate MIDI messages to the proprietary USB protocol used by Fender Mustang amplifiers. The bonus configuration is called 'mustang' and works with 3 momentary switches and 3 jog wheels.

Display mode

Where	What	Display	Description
Bank Name	Empty		If the current bank name is empty the current profile and the current bank is shown using a vintage 7 segment LED style. First digit is the profile, the others two are for bank.
Bank Name	Any		If current bank name is not empty the bank name is displayed within the 6 pedal names. PedalinoMini™ assumes the first action tag for the pedal as its pedal name. The bank name screen will switch every 4 seconds to display pedals current value if no event occurs.
Bank Name	:		If the bank name start with colon (:) the bank name is always shown (if no event occurs).
Bank Name	.		If bank name start with point (.) the current values are shown and events update values in real time without any display switch.
Bank Name	##	A double hashtag sign (##) in bank name is replaced with the bank number.
Action Tags	:		If action tag start with colon (:) the display is not switched when an event occurs.
Action Tags	.	![]()	If action tag end with dot (.) the corresponding led and color is set on boot.
Action Tag	###		A triple hashtag sign (###) in action tag is replaced with the current value of the parameter.

How to switch profiles

During normal operation

• Single press of BOOT button to move to the next profile
• Double press of BOOT button to move to the previous profile
• Long press of BOOT buttom to switch between live performance display and scrolling pages where configuration parameters (the device name, the IP address etc.) are displayed.

On TTGO T-Eight replace BOOT button with CENTER button.

End User Built (oldest first)

https://github.com/marosell More details

https://github.com/mknerr

https://github.com/alf45tar

https://github.com/jimhiggs

https://github.com/raidolo

https://github.com/bsos

https://github.com/rigr More details

https://github.com/Hans68 More details

https://github.com/teopost More details

https://github.com/gallochri More details

https://github.com/juani13973/pedalinio-18-footswitches-prototype More details

https://github.com/MaxZak2020

https://github.com/aFunkyBass More details

https://github.com/akosbeke More details

https://github.com/borsei222 More details

https://github.com/TarFilarek More details

https://github.com/bobvc133 More details

https://github.com/Samantha-uk More details

https://github.com/potul More details

https://github.com/Celticpure More details

https://github.com/jimhiggs More details

https://github.com/Keeze More details

https://github.com/mattzzw More details

https://github.com/Jelle7and9 More details

https://github.com/regisampa More details