mattzz

Thanks @datacommando - The thread inspired me to look under the hood of my Android phone (using the android debug bridge 'adb' over wifi...) and checking the logs while plugging the Helix into my phone: 03-13 21:46:50.500 1706 2159 W UsbACInterface: Unknown Audio Class Interface subtype:0xa 03-13 21:46:50.503 1706 1952 D EventHub: No input device configuration file found for device 'LINE 6 HELIX '. No bueno. This tells me that the OS indeed detects the LINE 6 device, however the software can't handle it correctly. OK, I guess we knew this already. The second line is not a problem. It is also present for my working USB-C to 3.5mm jack adapter. It basically detects a keyboard as an input device, which is also what a Mac does. However, the first line is a problem. I guess it has something to do with an USB subtype...

Hi, I am currently using a dedicated path from return 1/2 to output multi in order to loop in a backing track and it works nicely. Looping in audio 'should' also be feasible via USB 1/2 (setting USB 1/2 destination to multi in global settings) and using mutli as input. However, this does not work on my Android phone (Pixel 7a). The phone seems to detect the Helix LT when connecting my phone to the usb port in the same way it detects for instance an usb-c to 3,5mm audio jack adapter (usb settings change, phone switches off built-in speaker when connecting) but I don't get any audio on the Helix LT. What am I missing? Has anybody succeeded in getting this to work with an Android phone?

Awesome build! I built a simple two button MIDI controller based on the Arduino mini pro specifically for the Stomp (https://github.com/mattzzw/midi_muppet_hx_2btn). Feel free to check out the code, maybe you find something useful (e.g. midi channel switching and eeprom storage of configuration). Regarding web-editing I was thinking to switch to an stm32 based board (black pill or blue pill) using webserial in the browser in order to build something similar to the MC3. On the other hand it would probably be way easier using a ESP8266/ESP32 providing wifi and bluetooth capabilities. Way too much cpu power for a simple midi switch - but hey, who cares, right? It's 2022 so a simple midi pedal should be capable of opening up a wifi access point, providing you with a nice web gui... ;-)

New stuff in firmware 3.10: New MIDI message: CC 72 value 64-127 = next preset, value 0-63 = previous preset Much cleaner solution - I am totally ecstatic ;-)

Yay, with firmware 3.10 we can now enjoy the newly added Midi CC message 72 and step up/down through preset without using this nasty hack (switching modes and emulating footswitch). This will get rid of the flicker/delay the hack introduced. Check out the latest version at https://github.com/mattzzw/midi_muppet_hx_2btn By the way: Would anybody be interested in being able to configure the Midi channel of the Midi Muppet? Edit: This was a slow evening so I just added MIDI channel configuration to the MIDI Muppet :-)

OK, here is a small but quite handy update on the MIDI Muppet: While being in footswitch mode (where midi muppet will emulate FS4/FS5) you can now quickly switch to snapshot mode and back by long pressing the up button. (Same functionality applied to preset scroll mode already.) So let's say you are in footswitch mode because you pretty much stay on the same preset most of the time and you need to access different snapshots within this preset - voilà.

Yes, as the Arduino mini pro is basically a shrunken down version of the Arduino Uno (same chip, same port names just minus the USB serial interface) this should just work fine on the Uno as well. Just powering the Uno is different but straight forward by using the plug instead of the "raw" pin. The wiring diagram is on github and pretty much applies for Uno/Nano/Mini Pro.

There is a wiring diagram on the github page of the "MIDI Muppet HX". (Probably wouldn't hurt to add a Schottky diode for reverse polarity protection as well - Pesky details...) And yes, it IS a a fun weekend project :)

You can work around the missing CC messages for bank up/down by switching into scroll mode and emulate FS1/2 respectively and then switch back into stomp mode. This is what I'm using on my Midi-Muppet HX // HX stomp does not have a native patch up/dn midi command // so we are switching to scroll mode and emulating a FS1/2 // button press. void patchUp() { midiCtrlChange(71, 1); // HX scroll mode delay(30); midiCtrlChange(50, 127); // FS 2 (up) midiCtrlChange(71, 0); // HX stomp mode } void patchDown() { midiCtrlChange(71, 1); // HX scroll mode delay(30); midiCtrlChange(49, 127); // FS 1 (down) midiCtrlChange(71, 0); // HX stomp mode }

I am running the helix stomp on a ripcord 9V converter powered by a cheapo 5V 20000mAh power bank. It is important to make sure that the power bank is able to deliver up to 3A! The ripcord DC DC converter seems to be quite efficient as the unit is hardly heating up. It gives me more than 6 hours of play time. Works just fine for me.

Hm, I am not sure about this one for two reasons: 1. In my opinion the REC/PLAY/DUB workflow is the most generic one. However, I do realize that there are loopers out there that can be configured in a REC/DUB/PLAY workflow. I just think it is less common. Take a look at the Ditto X2 looper for example. And coming from the built-in one button looper the REC/PLAY/DUB workflow is pretty much what I am used to ;-) 2. I think it is less confusing if one button controls REC/DUB and the other button controls PLAY/STOP. Putting REC and DUB on different buttons seems very confusing to me. You can overdub simply by pressing sw1 again in playback: stop --> sw1 --> record --> sw1 --> playback --> sw1 --> overdub.

In order to find out which Arduino version you are using, measure the Vcc pin. This is the supply voltage of the MCU created by the onboard voltage regulator. But from what you are writing I'm pretty sure you are using the 3.3V version. Luckily MIDI works with 3.3V, so if you are using the 3.3V version you have to change the resistors for the MIDI TX line (pin 5 of MIDI plug) to 10 ohms and for the MIDI voltage reference line (pin 4 of MIDI plug) to 33 ohms. I will add that to the documentation.

Double check the connection to the MIDI pins - the pin assignment can be confusing, depending on which way you look at the plug. I found https://learn.sparkfun.com/tutorials/midi-tutorial/hardware--electronic-implementation to be a useful resource.

Good info, thanks. Also, feel free to check out the Arduino Code of my Midi Muppet for the HX Stomp on Github.

Modding the M-Audio EXP pedal is super easy. I modified the M-Audio EXP pedal by desoldering the white cable (ring) and connecting it to ground. Where the white cable was before, I used a piece of wire to connect it with the red cable. So that the result looks a bit more like this (leaving out the minimum depth resistor potentiometer in the schematic): +-------------------> TIP (red) | | | | +-+ | | 10k | |<----1kR--+ | | | +-+ | (white) | | +-----------+ | | | | v GND Works like a charm.

Thank you @soundog, appreciate your feedback! I made a couple of changes, the unit can now also control the looper as a 2 button controller (similar to well known 2 button loopers). In general, my assumption is that most people are interested in either switching back and forth between program up/dn and snapshot up/dn mode (plus bringing up the tuner). using the unit as FS4/FS5 while being able to use an expression pedal plugged into EXP1/2 using the unit as LOOPER controller

Hi, this is a little DIY project I built: It's a small Arduino based two button MIDI foot switch for the Helix HX Stomp. It is more flexible and more powerful than the "normal" foot switches connected via TRS cable and as a bonus you can still use an expression pedal hooked up to your HX Stomp. The MIDI Muppet HX can scroll through presets (normal mode) scroll through snapshots (snapshot mode) act as FS4/FS5 (fs mode) bring up the tuner (in any mode) To cycle through modes, press and hold the right (up) switch. To toggle the tuner, press and hold the left (dn) switch. If this is something you are interested in building please check out more information at https://github.com/mattzzw/midi_muppet_hx_2btn Other ideas are integrating tap tempo, looper control, ... Feedback and ideas are welcome! Cheers, /Matthias