Hi,

I’m new to raspberry pi and am trying to run Pure data on it to control a teensy 3.2 using Open Sound Control which in turn controls some stepper motors for a pump just like here https://github.com/DropletKitchen/pumpsn17 (using the teensy code and PD files provided at the end of the page). I’ve finally managed to install PD extended on my raspberry pi 3 (Raspbian Jessie). But I don’t think PD is able to use the USB to communicate with the teensy, since if I try to run the PD file, PD gives me the error “could not open device /dev/ttyS0: failure(13): Permission denied. Could someone help me please to get PD communicating with OSC through my USB?

Also when I open PD I get this message
“/dev/dsp (read/write): No such file or directory
(now will try write-only…)
/dev/dsp (writeonly): No such file or directory
/dev/dsp (read only): No such file or directory”
and
“Audio I/O stuck… closing audio”
Do I need to do some further configuration to get Pure Data running properly?
Like I mentioned I am very new to using the raspberry pi so any help would be appreciated and please do explain as if I were an idiot, that would be very helpful.
Thank you

First of all, why extended and not vanilla? Extended is no longer maintained.
About the Teensy issue, did you put the udev rules as suggested on Teensy's webpage in /etc/udev/rules.d?

@alexandros Thanks for your reply. I'm using extended as the PD file i am using requires a number of externals for it to work. PD-L2ORK would be great, but after a number of attempts, I can’t seem to get it working on raspbian Jessie, using step 3 on http://l2ork.music.vt.edu/main/make-your-own-l2ork/software/raspberry-pi/ (since I am not running it headless as I have a screen mouse and keyboard for the pi) the install seems to run smoothly but then after there is no trace of the program anywhere on my raspberry pi, just the download file sitting there. So I ended up settling for extended instead.
I should have the udev rules, since I installed teensyduino using the script here https://github.com/cmcmurrough/cse2100/blob/master/teensy/install_teensyduino.sh which also installs the udev rules.
Might the problems be with identifying/permissions for the correct output? In my case this is a USB to the teensy. I’m a newbie to both raspberry pi and PD, so don’t know if I need to/ how to pre-configure these (if I need to that is).
Thanks

@pmh1d15 Most likely you need to add your user name to the dialout group in linux. The teensy registers as a modem if I am not mistaken, and also anything involving comports also requires you to access dialout permissions to function.

in a terminal window, type

sudo adduser <USER> dialout

where <USER> is your user name. log out, log in and you should be good to go.
Cheers

Thanks for the suggestion Th8a. Since i am working as the user "pi" I am already a member of the dialout group. .. Just to update, I have now managed to install PD L2Ork. just using the same instructions as i mentioned before (so I don't know what happened first few times round). But I still get the same problems of not communicating with the right port, and also a number of errors stating "could not create" unpackOSC and a number of routeOSC elements

sometimes permissions with things gets a little wacky. You might try editing your visudo file to give the pi user more access. Also make sure the target port is not in use by some other process. Finally, in some cases I have managed to get things like this to work by force claiming ownership/access to a file using one of the two following methods:

sudo chown <username> <file name> (Claim ownership of a file)
sudo chmod 777 <filename> (assign read/write permissions for all users to a file)

Hope that helps

Thanks again for your reply, entered those commands and got the permissions. But looking into it more, it seems that permissions might not be my problem. Since it looks like I have the wrong output. It’s trying to communicate with the teensy through a pin out (/dev/ttyS0) rather than a USB port (like ttyUSB0). The problem is I’m not quite sure where or how to change where the OSC data is sent and received.

@pmh1d15 OSC is an IP network protocol. You will need Ethernet or Wi-Fi on the Teensy to "talk" OSC...... unless it is possible to get the Teensy to make its USB connector behave like a network port?...... maybe dangerous for future programming requirements?
At the moment it is behaving as a TTY port...... which is logical given that it is its only com port.

Either give it a network port......... https://forum.pjrc.com/threads/40238-Teensy-3-2-with-WIZ820io-and-OSC ......or convert your messages within PD from OSC to TTY data and use the USB connection.

However, looking at your OP link it seems that is exactly what is happening in "pumpsn17".
The patch [slipserial.pd] is doing the conversion to the teensy datastream.
So it is using the tty port and you should have a working system.....

Is [slipserial.pd] looking through the USB port to the pins on the Teensy...... is any voltage appearing on Teensy "S0".

More info here......
https://github.com/CNMAT/OSC
David.

@whale-av thanks for your reply. It looks like the [slipserial.pd] isn't finding the teensy. It's output looks to be addressed to:
/dev/tty.usbmodem12341 , pollintervall 1
when I look for my USB teensy using lsusb i find it here:
Bus 001 Device 006: ID 16c0:0483 Van Ooijen Technische Informatica Teensyduino Serial
although I dont know how this would translate into an address to give in the [slipserial.pd]. Doesn't it need to be a dev/tty... format?

@pmh1d15 I'm a pretty total Linux noob....
It looks like you need the format......
"devicename /dev/tty.usbmodem12341, baud 9600, pollintervall 1"
where baudrate is the baudrate, pollinterval the puredata controlrate (in ms); devicename the name of your usb port.
So I would imagine that you need to replace "dev/tty.usbmodem12341" with "dev/tty.usb0"....or something similar.

I would try..........
To find the "devicename"........ https://unix.stackexchange.com/questions/144029/command-to-determine-ports-of-a-device-like-dev-ttyusb0
So.....

#!/bin/bash

for sysdevpath in $(find /sys/bus/usb/devices/usb*/ -name dev); do
    (
        syspath="${sysdevpath%/dev}"
        devname="$(udevadm info -q name -p $syspath)"
        [[ "$devname" == "bus/"* ]] && continue
        eval "$(udevadm info -q property --export -p $syspath)"
        [[ -z "$ID_SERIAL" ]] && continue
        echo "/dev/$devname - $ID_SERIAL"
    )
done

David.

Thanks David, gave this a go, but still no luck. Looking at the errors on Pd i'm thinking it may be a problem with the different .pd files communicating with each other. If I open PD L2Ork on the Raspberry pi I initially get an error saying “audio I/0 error…”. If I open the PD extended program instead, I used to get the same error but then since typing:

sudo apt install alsa-oss
sudo modprobe snd-pcm-oss

in the command to create a /dev/dsp device as per the advice of another raspberry pi user. Not sure why there is the difference with Pd extended and Pd L2Ork but I don't think this is where my problem is.
If I actually open the Pure Data files that I need, in either of the Pd program versions I get:
UnpackOSC
… couldn’t create
routeOSC /derection
… couldn’t create
And then a bunch of other could not create warnings for all the OSC parameters. It seems like the OSC elements are not working. The PD L2Ork also identifies that the helper file o.io.slipserial.pd 5 0 4 0 (bng->loadbang) connection failed
Suggesting the communication between the “loadbang” control in the PD file and the helper file. although I am assured the PD files work. I’m trying to get in touch with the creators (to no avail). But if anyone here has any helpful suggestions I am all ears.

@pmh1d15 I don't know PD L2Ork at all..... but it looks like you have solved the audio for "extended"

[unpackOSC] and [routeOSC] are from the MrPeach library.... included with extended.
If you look in Pd/extra/mrpeach you should see the help files for them (you will not see them as objects.. as they are part of a library). Usually putting an object [import mrpeach] in the patch will make them work..... it forces Pd to load the library.
So it looks as though the patch was built with extended.

A connection fails when an object does not have a specific inlet or outlet for some other object to connect to as the patch is loaded... maybe because the object has not been created......
IT LOOKS LIKE..... the object [loadbang] that you have does not have an inlet (mine does).....
Just connect the bang to the same places as loadbang....... that will do the same job.

Out of interest, what did running the code in my last post (in terminal) tell you about the dev/tty connection?

PS................ I have downloaded it. [import mrpeach] has been added to [o.io.slipserial] so unless that is opened first (unlikely) you will get errors.
Add it to the patch that you open first (or all of them...... no harm can result)

PSPS............ In [Hardcoded4Pumps] clicking the [devices( message should print a list to the Pd window. This should do the same as running the code that I posted yesterday.
In [Flexible3or4Pumps] the same....... plus a radio button below to select the port.....
David.

@whale-av Thank you David! The Pi is talking to the teensy!!! Your help and persistence with my problem is really appreciated! Like you suggested I added [import mrpeach] as an object in the Flexible3or4PumpsGOP file and it is now talking! My stepper motors step, and my pumps are working!. And it seems to work on both extended and L2Ork. Yet to test whether they are running at the correct speed as per the controls though.
I do however still get some errors saying [import mrpeach] …couldn’t create. Maybe I added it wrong, should I not be adding it as an object? Also when I play with the control sliders it reports that “packet size is not a multiple of 4 bytes: dropping packet” And then sometimes “unpackOSC: dataafteralignedstring: incorrectly padded string” and “Bad message name string:Dropping entire message”.
I’ll have to check physically if my pumps are running at the correct flow rates to see if this is effecting performance, but sadly this will be after the weekend.
I’m so happy that I have them communicating now though. Thank you. It's been a long time and I was beginning to loose hope.
It is communicating with the teensy through ttyACM0 at the moment. I had previously done some swapping around of ttyS0 and AMA0 on the pi, since apparently on the Pi3 the Bluetooth steals the AMA0, when I did this ttyS0 became available as a port. But before trying your fix I changed it back to as the Pi was and now only the ACM0 and AMA0 are available (Yes the devices button was very helpful).

@pmh1d15 That's good news.....
I would add [import mrpeach]...... (as an object..... you are correct).... to every patch. Open each patch including the "Flexible3or4PumpsGOP.pd"....... and add it to all. That should fix the "cannot create".

Google will have to be your friend for the "packet size is not a multiple of 4 bytes: dropping packet" problem. Google throws up quite a few discussions that are relevant......

Someone mentioned it in this thread...... https://forum.openframeworks.cc/t/sending-osc-over-slip/18306/20 ........ and although no-one answered there was a lot of discussion of the microprocessor side of the tty connection....... etc.

But this might be more useful...... as I expect that it is a problem with the data being sent back from the Teensy.......... https://cycling74.com/forums/max-receive-udp-message

David.

@whale-av I think you are right on the packet size being the teensy talking back, since the data to the teensy (and hence pump speeds) all seem to be correct. Thanks again David. You have been a great help.