Official RBPi TouchScreen 7"


Just tried and yes!! it works on hw0 and now for some reason … I think I played with the alsamixer everything works fine in all engines… including mod I can distort my voice in real time all working finally thank you for your help!!!


Yeahhhh! Really great news, @cryoshad!

Probably you are the first person using Zynthian as an effects proccessor (audio input). Congratulations!

I will be the second one :wink: My audioinjector is waiting for me …

Kind Regards!


Congratulations!!! @cryoshad.

When I met Zynthian this was my goal: have a fully functional touch interface for a simplier build (avoiding enconders, pcb’s, etc). I just wanted my Zynthian to “enjoy myself” at home. I guess those who plan to use Zynthian on stage should feel more confortable with a pysical knob to play.

A few questions now…

Did “I2S SYN error!” message disappear? If not, do you hear something wrong (clicks, pops…)? what about latency?

How about sound quality? (compared to the iqaudio that you own)

Do you know if input and output gain can be controlled by sw instead of physical potentiometers? I gess the answer is yes.

Enjoy your new little toy!

Regards, Jose


Congratulation for this new interesting way of using Zynthian…i am also interesting at the possibility of using Zynthian for a guitar processor (my son plays guitar…) …


Hello @smespresati,

Q1: Yes the I2S SYNC is still there. But I do not notice any clicks or pops
Q2: Latency is to my ears very acceptable … I do admitedly notice a very small delay but for voice it is fine. Not sure about fast guitar picking… though…I might have time to plug my oscilloscope one day and get you a metrics.
Q3: Sound quality is good but if you do have the right levels in the alsamixer, But if you go louder you can definetely hear some white noise.
Q4: yes the alsamixer works fine and has a “MASTER” level as well as an "output mixer"
Q5: Also it seems that the audioinjector is much less sensitive to “low voltage” than the iqaudio.

As a mater of fact I can drive: raspberry pi3 + audio injector + 7’’ touchscreen + novation launchkey 25 + some basic speakers… all those powered from the the micro usb of the rasbperry pi with a single 2.4 Amp usb powersupply

Finally I enclosed the electronics tonight and I am pretty happy with the result. I’ll add some pics. :wink:



Hello I have taken an oscilloscope and traced input vs output signal using mod with a direct connection and a detune module.
I get a latency about 10ms if I go direct in mod and 20ms with the detune.
Obviously I removed the line in-line out bypass in the alsamixer otherwise there was no measurable delay…

7 new photos added to shared album

I have also added pictures of my box connected to the zynthian headphone and ready to play.

It’s really an incredible toy and my kids are going crazy with the voice detune…

I guess the only thing which would be needed now is the ability to control from the launchpad a simple looper or a miniature sequencer like this one…

But maybe I am dreaming or simply a bit spoiled by now… :pensive:

Anyway I found my launchkey programmer’s reference manual here … so I could just start coding :fearful:


Hi Guys!

I’m having the same issues with AudioInjector.

I set up my Zynthian with a 7 "HDMI screen with the instructions this link:

and tried the settings placed here, but I did not succeed.

Any tips on how to make the audio injector work?

Thank you


Hi @rod_amaral!

Note that audioinjector uses some GPIO pins that are already used by Zynthian default configuration (the last statement is incorrect and amended in another comment below …). Althought you have no rotary encoders in your setup, Zynthian UI will try to read from it. I’ve fixed this in the last software version, so you should try it:

When you have correctly updated the UI software, you should edit the config file “” and configure the GPIO layout as “dummies”:


This will prevent the zyncoder library to try to configure and read the rotary encoders & switches.

Kind Regards!


Thank you @jofemodo! I’ll try it today!


Excuse me, @rod_amaral!

I’ve checked the GPIO layout and there is no conflict. Audioinjector don’t use any GPIO pin currently used by Zynthian, so it shouldn’t be conflicts.

Just now, i’m trying to configure my audioinjector. I will give some feedback … :wink:



Whew, you almost made me nervous. I have the audioinjector working just fine for output, but I’m still waiting for a cheap Chinese lcd to arrive. The kids don’t really appreciate when I’m using the TV as hdmi display. :grin: In the meantime I’m trying my luck with toner transfer for the pcb’s. I haven’t etched a board since 8th grade :thinking:


I’m burning a new image right now. I hope to give you feedback too! :+1: :+1:


Good news! The audioinjector works perfectly, even without the zynthian-ui update.

I had forgotten to configure alsamixer to enable audio output. :frowning2:

However, for now, i can only use the audio output, the input still could not make it work.


Audio Input Working too! :raised_hands:


Greaaaaat! Can you explain how did you make it work?



Here’s what I did, in order:

  1. I installed a clean image of the zynthian gongorna
  2. Run apt-get update, upgrade; Upadte-dist; Rpi-update and reboot
  3. Update Zynthian
  4. Since I’m using an HDMI screen, I followed the steps in this post
  5. On file /zynthian/zynthian-ui/ changed:

function alsa_in_start() {
Start alsa_in audio input
while [ 1 ]; do
/usr/bin/_alsa_in -d hw:0
sleep 1
6) Alsamixer Configuration:

And it worked perfectly!

Here a little set:

For guitar the line input of the audioinjector is not very good, so I’ll have to build a preamp to send a bigger signal.

As soon as i can organize the assembly a bit, I’ll create a post with the step by step and the results

Thanks again!

Zynthian Box with Audio-input (Audioinjector soundcard)
Zynthian Box with Audio-input (Audioinjector soundcard)

Hi @rod_amaral!

Normally, this step is not needed and could break something, specially MIDI-IN, but if it worked, OK, it’s better to have an updated kernel and firmware :wink:

This is not needed, but. It’s intended for using an extra USB card, but i think it wouldn’t be needed never more.
Better to ignore. I will remove this function in the next release.

The key part is alsa mixer :wink:



To be honest I am trying to replicate and take down notes but it doesn’t
work anymore I think my daq+ soundcard gets in the way now that I received
it… it’s a mess… lost a few hours already… :wink:


Hey all,
So i have a RapsberryPi official 7 inch display and an audioinjector. And I found that if I connect it to the SPI interface the audio injector stops working, but if I only connect the ribbon cable and the power it works. Strangely enough the touch screen also works.


I’ve got a 7" touch screen working with an audio injector on it’s back. No knobs.