EC11 Encoders issues on V4 Custom + FluidSynth/LinuxSampler not visible in UI (Oram-2601.1)

Hardware
1 
Hello Zynthian community,

I've built a custom Zynthian V4 with the following hardware:
- Raspberry Pi 4B
- RaspiAudio DAC (using HiFiBerry DAC+ light driver)
- 1TB NVMe SSD (52pi adapter)
- OSOYOO 5" DSI touchscreen
- 4x EC11 rotary encoders with switches
- M-Audio Keystation 88 (USB MIDI)
- ZynthianOS Oram-2601.1

I'm experiencing two main issues:

**ISSUE 1: EC11 Encoder switches not working properly**

Hardware configuration:
- EC1: CLK=GPIO26, DT=GPIO25, SW=GPIO6 (Pin 31)
- EC2: CLK=GPIO4, DT=GPIO5, SW=GPIO7 (Pin 11)
- EC3: CLK=GPIO27, DT=GPIO17, SW=GPIO13 (Pin 33)
- EC4: CLK=GPIO23, DT=GPI24, SW=GPIO12 (Pin 32)

Webconf wiring:

ZYNTHIAN_WIRING_LAYOUT=“CUSTOM” ZYNTHIAN_WIRING_ENCODER_A=“26,4,27,23” ZYNTHIAN_WIRING_ENCODER_B=“25,5,17,12” ZYNTHIAN_WIRING_SWITCHES=“6,7,13,12”


Problem:
- Rotation works perfectly for all 4 encoders
- EC2, EC3, EC4 switches work
- **EC1 switch (GPIO6) does NOT work in Zynthian UI**
- GPIO6 test via Python works perfectly (reads 0/1 on press/release)
- System log shows: `ZynCore: Configured 4 x Logical Zynswitches... ZynCore: Setting-up 3 x Physical Zynswitches...`

Only 3 switches are configured instead of 4!

I suspect GPIO6 has some incompatibility with libzyncore. Would GPIO11 be a better choice for EC1 switch?

**ISSUE 2: FluidSynth and LinuxSampler not visible in UI**

Both engines are:
- ✅ Installed (`/usr/bin/fluidsynth`, `/usr/bin/linuxsampler`)
- ✅ Engine files present (`zynthian_engine_fluidsynth.py`, `zynthian_engine_linuxsampler.py`)
- ✅ Enabled in Webconf Engines Manager
- ❌ **NOT visible in "Add Instrument Chain" menu**

Available engines in UI: amsynth, Calf Monosynth, Dexed, Fluid SynthFX, Helm, ZynAddSubFX, etc.
Missing: FluidSynth (standard), LinuxSampler

I have 6 SoundFont SF2 files (611MB) in `/zynthian/zynthian-my-data/soundfonts/sf2/` but cannot access them because FluidSynth doesn't appear in the UI.

Note: "Fluid SynthFX" is available but doesn't load external SF2 files - it only shows MIDI controllers.

Has anyone experienced similar issues? Any suggestions?

Hardware tests passed:
✅ Audio output (RaspiAudio works)
✅ MIDI input (M-Audio Keystation works)
✅ Touchscreen works
✅ All encoder rotations work
✅ EC2, EC3, EC4 switches work

Thanks in advance!
Roberto
1 Like
2

Look in the sampler category :wink:
FluidSynthFx is a plugin with hardcoded sounds

3

Hi Jofemodo,

first of all I would like to thank you for your answer. I’m here to ask for a bit more help, due to the fact that I wasn’t able to find any sampler category. I searched by “sampler”, “sampler category”, “FluidSynthFx”, but I didn’t find anything. If you can indicate any link I’ll appreciated a lot.

Again many thank and regards

Roberto

4

Engines are sorted into categories in the UI. You switch between categories with the left/right keys or encoder 3.

This has been described A LOT in the forum and described in the wiki user guide.

I wonder what else we can do to make this recurring issue more accessible?

[Edit] I have created a ticket for the issue of new users not finding the category feature.

5

I have a nice idea to fix this “issues” forever :grin:

6

If we were to display three prominent messages on a startup screen, what would those three messages be?

1/ When loading engines remember they are in categories. An encoder ( version dependent ) selects them.
2/ All switches have 3 press lengths: Short, Bold & Long. They do different things
3/ …..

This should be spoken ( a wav file on start up) on newbie start up.
We have the advantage that this is, primarily, an audio device so we can rely on the presence of sound, but not necessarily display.

If they hear this they know they have constructed correctly.

We could go really basic, and ask for confirmation by encoder presses . . .

Mustn’t get ANYWHERE near a live performance….

7

For the engines selection, i want to add a third columna, at right, with the list of categories. With the right layout It would look as side-tabs

Regards

1 Like
9

Hello Everybody,

first of all I apologize to bother you on the same newbie questions. I don’t want to excuse me but before to ask for your help I tried to read the User Guide but I found it complex (for me at least ;-))). I‘ve found a wyleu’s guide on the hardware wiring very useful. Thanks to him I was able to solve the Encoder wiring. Now I learn how to make the right combination between Encoders in order to access to the Sampler or FluidSynth FX/FluidSynth SF2 SF3 category. Unfortunately I wasn’t able to find it in the I list under the “Add Instrument Chain” and I tried to push in many different manner the Encoder 3 and Encoder 4. In a certain moment I’ve seen the Sampler and I was able to see my external SoundFonts charged but I wasn’t able to replicate the Encoders combination. Before to write you I tried for many, many times but no “luck”.

Many thanks in advance for your time answering me again and my best regards.

Roberto

PS: Zynthian project is GREAT!

10

When seeing the engine list, presumably the synthesizer engines, you should be able to switch categories by turning clockwise (not pushing) encoder 3. In case your encoders do not work as intended, try to drag the “category” field with you touchscreen input vertically. If that works, your encoder has a malfunction.

2 Likes
11

Many thanks hannesmenzel! You’re right! Now I’ve more clear the approach!

Many hanks for your time and best regards

Roberto

2 Likes