Allfifthstuning

There's a great audio repository for Debian/Ubuntu KXstudio, which I use on my laptops along with either Debian of (K)Ubuntu. I understand that I can't use this on the earlier PC One board due to the fact that the SSE2 instruction set isn't supported. Does anyone know if this is still the same for this newer board? Hans

I've tried the first but I don't think there's a real improvement. On my laptops I also stopped using rt-kernels, the standard kernel seems fine. The above mentioned tweaks are important though: - Adding yourself to the audio group - Setting RT audio settings - Setting CPU governance to performance Hans

Thanks Igor. I'll probably rethink what I want. A regular small HDMI screen with a small keyboard will be fine for what I want and would be a lot less hassle to get it up and running. btw. Would it be a good idea / useful to add the tweaks I made to make Armbian suiteable for rt-audio somewhere in the documentation-section? Although I'm not an expert, I could type the text. Hans

Phase one is finished for now: I've got Guitarix up and running. The developer made a "trimmed" version, with some CPU-consuming processes switched. There's a trade of in the sound qualitty, but in everyday use it won't be noticable. A 48k samplerate seem to be the maximum the Pi can handle, higher samplerates will result in hick ups, the so called Xruns. The package can be downloaded here. You have to install the dependencies, before you can build it. After going back and forth using a realtime kernel, i've settled to use the "standard" kernel for simplicity's sake, there was no real improvement using the rt-kernel. As mentioned earlier, I've added myself to the Audio group and tweaked some audio settings. One very important thing to do is to set the cpu governance on "performance", this really helps to lower the amount of xruns. I also isolated two out of four cores to direct the audio processes to. The improvement is small, so it can be done with. So long story short: OPi can be used with guitarix! Now: phase two, getting a small tft touchscreen to work on the Pi. It is a screen which is used on RPi-B's with succes. I've only connected it once and it lit. Although I've searched the internet / this forum, I still don't know route to take to get it working. Could someone advice me on this? Hans

I've build a new os. It runs, but the screen is a bit distorded, iit looks like a lot of pixels aren't "activeted" Further I try to install libgtk-3-dev which is needed to build guitarix, but I get this message: root@orangepipcplus:/home/broomy/Programs/guitarix-git/trunk# apt-get install libgtk-3-dev Reading package lists... Done Building dependency tree Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: libgtk-3-dev : Depends: libglib2.0-dev (>= 2.41.2) but it is not going to be installed Depends: libgdk-pixbuf2.0-dev (>= 2.27.1) but it is not going to be installed Depends: libpango1.0-dev (>= 1.36.7) but it is not going to be installed Depends: libatk1.0-dev (>= 2.7.5) but it is not going to be installed Depends: libatk-bridge2.0-dev but it is not going to be installed Depends: libcairo2-dev (>= 1.10.0) but it is not going to be installed E: Unable to correct problems, you have held broken packages. Hans

Ok wil do.

This may be an obvious question, but how do I do this? I can't seem to find the right instructions...

Would it be doable / advisable / useful to patch the kernel to make it realtime and tweak it from then on, as is described here?

Transfered everything to emmc, from what I can see, there is not a big difference noticable. Hans

Thanks Igor, that's sound advice. I haven't installed Armbian on eMMC yet, will do that. I've contacted the developer of Guitarix it there is still some tweaking within Guitarix possible so I'll try that also. Hans

Alright time to make an evaluation of the process so for. Firstly: I'm impressed of the capabilities of a SBC (i.c. the OPiPC+), it will suit my daily needs: emailing, text-processing, internetsurfing and so on. All can be done without a breeze. With -of course- Armbian on the background "doing it's thing". Great! After going back and forth using different flags to configure and build Guitarix, it is now running stable with a relative low latency. One thing which has to be dealt with is that the number of effect which can be used simultaneously is a bit limited, because I run out of DSP power pretty fast (although I tweaked a lot with using designated cores / higher set priorities). Over at the Linuxmusicians forum someone suggested that I may have to use buildroot to start from scratch. Currently this is a bit to big to chew for me. What can I do to optimize Armbian to free up more resource? Install an even lighter gui like LXDE or openbox? And how can I do that properly (I've tried it but I can't switch to an other session)? Start with Armbian server and install openbox or lxde (which I tried but didn't work so far)? Deinstall several services to make everything lighter? Hans

Alright I'll try that. If assigning IRQ help, I would gladly try that out. unfortunately it's not my faint heart (as far as I know of) that bothers me, but my infinite lack of knowledge when it comes to programming / setting up pc's. But I'm working on it... ;-) Hans edit: Found this thread showing how to update boot.scr edit 2: CPU 2 and 3 (starting from 0) are now isolated, which I verified by using: top and then pressing "1" Then in a terminal I use taskset -c 2,3 ProgramOfMyChoice to assign the programs to the right cores, Guitarix is still a bit buggy when I use the factory presets though.

That's a good tip! I've managed to use "taskset" to run Jackd and Guitarix on a specific core. I've did a search on where to place the "isolcpus=" argument, but haven't found the right place where I can put it. Where do I have to put it? And can I reserve two cores or would that be over the top? Hans

Thanks that did the trick. Thanks, screen is now setup fine. I've got Guitarix (build from source) up and running with a latency under 10ms (which is pretty decent), although it is a bit unstable (getting xruns) when using certain effects. Next step is to streamline the whole setup to minimize the xruns. Hans

Alright thanks, I will try that. Hans

in another thread TKaiser gave me the tip to use H3disp for setting my screen. I was wondering, can I set my screen resolution before I boot for the first time? (Thus, on the computer where I flash the image on the SD card) This because I use a HDMI to DVI adaptor, so on the initial boot the screen stays black. Hans

One thing I notice is that I can't copy text in and from a terminal to another program when using desktop, do have to change a setting? Hans

Alright got the OPi up and running with an HDMI to DVI adaptor. Steps I took: 1. Flashing the newest Armbian version to a SD card 2. editing the script.bin file (converting it first with bin2fex to script.fex ), by adding two lines at the end of [hdmi_para]: hdcp_enable = 0 hdmi_cts_compatibility = 1 (and convert it back using fex2bin) to make the HDMI to DVI adaptor work. 3. boot the SD card and follow the instructions 4. Installing jack2 and qjackctl and guitarix (first the standard version later building it from source) 5. Adding myself to the audio group usermod -G audio your-user-name 6. Tweaking limits.conf in/etc/security/limits.conf by adding: @realtime - rtprio 90 @realtime - memlock unlimited 7. Reboot 8. Turning wifi of in a terminal: nmcli r wifi off Then I attached my usb soundcard and configured jack using qjackctl (48.000 / 3 periods / 256) and then fired up Guitarix: Working! A good start so far!

THe OPiPC+ arrived and I'm trying to set it up. I can only use av output since I don't have HDMI. With the standard Android OS the OPi outputs video through av. With Armbian I can't get any output yet. I tried to modify the script.bin file as is written on the Orangepi site but with no luck. I'm using the latest Armbian version on a 16GB class 10 Samsung EVO. What can I do to check if the OPI boots at all? How can I make the OPi output video on the AV channel? Do I have to make a custom kernel? Hans

Thanks for your reply. I'll update on the Guitarix forum as well! The spam is a bummer indeed! Hans

@Autostatic: Is your repo compatible with Armbian? That would be great. Hans

Is the SP1 LCD interface supported within Armbian? And the XPT2046 touch screen controller? These questions may be well documented on the FB-group but I don't have an account (and rather keep it that way), but more so FB is shut off when using internet on school I teach (where I finally want do something with the Armbian equipped Pi boards). Hans

Yep it's usb 2.0. Hope the OPi arrives soon, so I can get started. I'll keep posting.

Thanks Autostatic for joining! Alright I will go for a commandline setup, will Armbian server do or do you recommend another distro? The soundcard had some issues with pc's with usb 2.0 and usb 3.0 ports. The newer kernels have some kind of bug which makes for tons of xruns. On a fully usb 2.0 laptop the problem doesn't arise. I've fired up an old laptop recently and it works flawlessly. Hans

Ok. And guitarix works for other instruments as well... Thanks!