Patchbox OS image 2020-03-14 (and MODEP)

Hey guys! Here’s the new Patchbox OS image with support for RPi4 out of the box and updated software. And the patchbox utility now lets you install MODEP as one of the modules!

It has the 4.19.71-rt24 real time kernel integrated by default.

Checkout the previous [Beta] Patchbox OS image 2019-02-27 (Updated 2019-03-13) release information for some useful getting started tips.


Default Passwords

User name patch
Password blokaslabs
WiFi SSID Patchbox
WiFi password blokaslabs

The WiFi hotspot is on by default.


To get MODEP installed, run patchbox, go to modules and pick modep. Then open http://patchbox.local on your computer if you are on the same network as the device, otherwise, figure out the IP of the device and use it with http like this: (this is the default IP if the device is hosting a WiFi hotspot)

Main Software Versions

  • Audacity 2.2.2
  • Pure Data 0.50.2
  • Pianoteq Standard Trial 6.6.0
  • SuperCollider 3.10.0

Known Issues

  • The 4.19.71-rt24 kernel seems to have some issues with Bluetooth, so the Pisound App connection keeps getting disconnected after a few seconds. This can be worked around by installing regular kernel. Fortunately this operation is very straightforward.

    To install ‘stock’ kernel, run: sudo apt install raspberrypi-kernel
    To install ‘realtime’ kernel, run: sudo apt install raspberrypi-kernel-rt

Let us know if you find any more issues or have any feedback!


Nice this is a great new addition…

This is great news that we can have Patchbox and Modep on the same OS!

Are you aware of which upstream bug is tracking the RT kernel bluetooth disconnects?

I don’t think it’s reported yet, I’m thinking about coming up with a consistent repro case using some BlueZ example code and create the report.

just installed it, can’t run startx

displaying this message
X.Org X Server 1.20.4
X Protocol Version 11, Revision 0
Build Operating System: Linux 4.15.0-48-generic armv8l Raspbian
Current Operating System: Linux patchbox 4.19.71-rt24-v7+ #1 SMP PREEMPT RT Wed Mar 11 16:54:08 EET 2020 armv7l
Kernel command line: coherent_pool=1M 8250.nr_uarts=0 bcm2708_fb.fbwidth=1280 bcm2708_fb.fbheight=720 bcm2708_fb.fbswap=1 smsc95xx.macaddr=B8:27:EB:07:7B:88 vc_mem.mem_base=0x3ec00000 vc_mem.mem_size=0x40000000 console=ttyS0,115200 console=tty1 root=PARTUUID=3ac474d7-02 rootfstype=ext4 elevator=deadline rootwait
Build Date: 05 June 2019 12:49:54PM
xorg-server 2:1.20.4-1+rpt1 (
Current version of pixman: 0.36.0
Before reporting problems, check
to make sure that you have the latest version.
Markers: (–) probed, (**) from config file, (==) default setting,
(++) from command line, (!!) notice, (II) informational,
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: “/var/log/Xorg.0.log”, Time: Mon Mar 16 12:43:10 2020
(==) Using system config directory “/usr/share/X11/xorg.conf.d”
modprobe: FATAL: Module g2d_23 not found in directory /lib/modules/4.19.71-rt24-v7+

i am using onboard sound

This does not seem to prevent the graphical environment from working - after running startx, you should be able to connect with VNC anyway or use your HDMI display. Also in the ‘boot options’ menu of patchbox you may make the Desktop mode the default one.

Very pleased to see an updated version of MODEP !
I have installed it on Pi3B
However I would like to report some problems:

  • The ‘Midi Learn’ function don’t work for pot (rotary) controls, but work for on/off controls.
  • Also, the ‘snapshots button’, left to ‘New Pedalboard’ dont appear consistently.

I would like to try to correct these but need advices on the related files …

thanks for the update.
tried it today with pi4, old version pisound,
got everything working except for jack.
can start jack with pisound.

Which config parameters did you use for Jack? The most important one is the sampling rate - Pisound supports 48, 96 or 192 kHz.

I reinstalled the image, now it works. checked several setups (48 or 96, 64/128/256 blocksize, 2)
But have to start jack manually after every startup via patchbox setup.
(auto-login to user patch, desktop GUI on)

And it runs all fine, when starting the pure data module via patchbox-config.
… think I just missed selecting that. :slight_smile:

Just found out, that the issues seems to be the fan SHIM software.
The autoscript controlling the fan seems to conflict with pisound / pisound button.
when leaving the autoscript off… everything is fine.

What is the Fan Shim you are using? What is its button supposed to do?

It is the Fan, mentioned by @rbn here: PiSound with Raspberry Pi 4
After starting the background process described here pisound button reacts not or with a several seconds long delay.

The button on the Fan is used for manually switching it on/off apply it to trigger other functions/scripts.
To me it appears, as if the fan button and pisound button are both connected the same way to the Pi, and so one also switches for the other.

That is no problem, if it is possible to control the fan with terminal or scripts. But when using the python scripts as described in the Fan Shim Manual, pisound button does react strange and all related processes (like Pd Startup) become very very slow, and then there is no Audio coming out, until turning the processes off and rebooting.

Sorry, that I cant offer any better help in this case and just can describe. But
solving this issue would make fan work, that fits perfectly between Pisound and Pi and does not require soldering. Think this could be a great option for a lot of people.

1 Like

Thank you for reporting these issues, I have released a fix for the MIDI Learn and will look into the other issue a bit later.

Anyone experiencing the MIDI Learn issue may get the fix by running:

sudo apt update && sudo apt install modep-mod-ui

Indeed, the same button pin is used on Pisound :slight_smile: @rbn, any advices on how to get it play nice together with Pisound?

Btw, I see the fan uses BCM 18 too which is actually critical for the I2S audio interface, so if possible, any fan functionality related for that pin should not be used. This is a quote from Fan SHIM product page:

Because Fan SHIM uses pin BCM18 to control the fan, and this pin is also used by I2S audio devices, you won’t be able to use I2S DACs like pHAT DAC, pHAT BEAT, and the IQAudio boards at the same time as Fan SHIM

1 Like

Hey this is great! I’ve been able to get Modep working, however so far have been unable achieve this
without logging in with a keyboard/monitor every time i boot up.

No option for auto login seems to appear in sudo raspi-config.

How can I achieve this?
Thanks so much!

Hey, do you mean you must login manually in order for MODEP to work? Or you simply want no login prompt after booting the system?

If you want auto login, run sudo raspi-config, go to 3 Boot Options, then B1 Desktop / CLI and pick one of the options with ‘Autologin’ in them.

I have added the autologin options to patchbox->boot menu. You simply have to run patchbox->update to get the config utility updated.

This issue is now fixed as well, again, run the same command to get the fix:

sudo apt update && sudo apt install modep-mod-ui

Yeah, for some reason the usual boot options that include auto login aren’t showing up.
I’ll run patchbox-update and give the options you added a try.

Looking forward to trying this! Will your MODEP packages work on a regular Raspbian setup, and if so, is there a place to grab the binary packages? Thanks!