• Hardware

  • is anyone successfully using i2c OLED / LCD?

@Flowdeeps - I ended up taking a different route. My goal with the oled screen was to try any get an oscilloscope that I could use to monitor modulation in real time. I attempted to implement the Display() function the way that Giulio had recommended by grabbing a screen's worth of pixel values in an array and populating them every 20ms, but I wasn't able to get the array values to populate correctly - I'm not a particularly good C / C++ coder...

In the end, I resorted to setting up a wifi connection between my phone and the effect pedal I was building with a little wifi dongle and using the IDE oscilloscope via DAC 27. This worked really well for my application and honestly feels a little like the OP-Z use of a phone as a "screen".

I might try my hand at it again at a later date, but this isn't on my short list of projects to come back to.

20 days later
10 days later

Hey guys,

Is it possible to use two devices at the same time (trill craft + oled screen) on the pins SDA, SCL, V+ AND GND of the bela black?

    RafaeleAndrade
    they are all I2C, so im hoping as long as they have different addresses this would be possible.
    (this is whats happening with the 2 oleds on the TT above)

    once the trill arrive, Im planning on making something with a few trill, a couple of i2c encoders and an oled !

    the guy who supplied me with the above Terminal Tedium, pointed me to these :

    https://www.tindie.com/products/saimon/i2cencoder-v21-connect-rotary-encoder-on-i2c-bus/

    they are not cheap, but the idea is Im going to add one or two to the above terminal tedium 'expander',
    and also use a few with the trill/bela 🙂

        thetechnobear they are all I2C, so im hoping as long as they have different addresses this would be possible.

        Yes. Each type of sensor has a dedicated range of address, which are non-overlapping between sensor types. You can set the sensor to a different address by applying a tiny amount of solder on the board to bridge two pads together.

            9 days later

            giuliomoro Thank you. I've got this mostly to work. However whenever the OSC2OLED program runs for the first time when the Bela is started I am getting this error:

            alt text

            If it is run again the program runs fine and there is no error message. However when running it from start up it stops the other Bela program that is enabled to run on start up.

                giuliomoro changed the title to is anyone successfully using i2c OLED / LCD? .

                giuliomoro No just the OSC2LED. The Bela program is just a simple pd sketch that is sending OSC data to the screen for testing purposes at the moment.

                  insignificatother However when running it from start up it stops the other Bela program that is enabled to run on start up.

                  Can we see the .service file? Also, what is the log of the Bela program that runs on startup, and what is the log of your program running at startup? You can achieve such logs with journalctl -fu SERVICENAME

                    Here is the .service file

                    [Unit]
Description=OSC to IC2 Screen Launcher
After=network-online.target

[Service]
ExecStart=/root/Bela/scripts/run_project.sh Screen_Test_Error
Type=simple
Restart=always
RestartSec=1
WorkingDirectory=/root/Bela/projects/Screen_Test_Error
Environment=HOME=/root
KillMode=process

[Install]
WantedBy=default.target

                    Here are the logs

                    root@bela:~# journalctl -fu bela_startup.service
-- Logs begin at Thu 2016-11-03 17:16:43 UTC. --
Nov 03 17:16:56 bela stdbuf[293]: sigmund~ version 0.07
Nov 03 17:16:56 bela stdbuf[293]: Bela digital: channel 0 is set as input at message rate
Nov 03 17:16:56 bela stdbuf[293]: Bela digital: channel 1 is set as input at message rate
Nov 03 17:16:56 bela stdbuf[293]: Bela digital: channel 2 is set as input at message rate
Nov 03 17:16:56 bela stdbuf[293]: Bela digital: channel 3 is set as input at message rate
Nov 03 17:16:56 bela stdbuf[293]: connecting to port 7562
Nov 03 17:17:00 bela stdbuf[293]: Makefile:570: recipe for target 'runonly' failed
Nov 03 17:17:00 bela stdbuf[293]: make: *** [runonly] Terminated
Nov 03 17:17:00 bela systemd[1]: Stopping Run Bela at boot...
Nov 03 17:17:01 bela systemd[1]: Stopped Run Bela at boot.
                    root@bela:~# journalctl -fu custom_program 
-- Logs begin at Thu 2016-11-03 17:16:43 UTC. --
Nov 03 17:17:03 bela systemd[1]: custom_program.service: Service hold-off time over, scheduling restart.
Nov 03 17:17:03 bela systemd[1]: Stopped OSC to IC2 Screen Launcher.
Nov 03 17:17:03 bela systemd[1]: Started OSC to IC2 Screen Launcher.
Nov 03 17:17:04 bela run_project.sh[681]: Checking the board is up and running at root@192.168.7.2...Warning: Permanently added '192.168.7.2' (ECDSA) to the list of known hosts.
Nov 03 17:17:03 bela run_project.sh[681]: done
Nov 03 17:17:03 bela run_project.sh[681]: Board found at root@192.168.7.2
Nov 03 17:17:03 bela run_project.sh[681]: Running Screen_Test_Error...
Nov 03 17:17:03 bela run_project.sh[681]: Pseudo-terminal will not be allocated because stdin is not a terminal.
Nov 03 17:17:04 bela run_project.sh[681]: make: Warning: File 'libraries/UdpClient/build/UdpClient.d' has modification time 96520642 s in the future
Nov 03 17:17:05 bela run_project.sh[681]: Running /root/Bela/projects/Screen_Test_Error/Screen_Test_Error

                      insignificatother ExecStart=/root/Bela/scripts/run_project.sh Screen_Test_Error

                      run_project.sh is going to call make stop, thus killing the other program. You should run the program directly with /root/Bela/projects/Screen_Test_Error/Screen_Test_Error.

                        And it's working. My noobness it showing. Thank you so much for your help and quick responses.

                        a year later

                        So here's a summary HOW-TO, for posterity:

                        • add this project to your Bela projects: http://github.com/giuliomoro/OSC2OLED4Bela . If you use a different project name, replace OSC2OLED4Bela with your project name in all the steps below.
                        • open the project and build it. When running, it will not emit any audio, but you should be able to send it OSC messages on bela.local:7562 from the host computer. You can run it like this for testing.
                        • to see what messages and formats are supported, see the parseMessage() function in render.cpp. For instance, you can send /osc-test followed by a float, /tr followed by a float (ignored) and/or a string, /param1 followed by a float. You can edit the program to change or add support for OSC messages
                        • when you have a reliable way of sending OSC messages to it from the host, create a file /lib/systemd/system/osc2oled.service with this content:
                        [Unit]
Description=OSC to IC2 Screen Launcher
After=network-online.target

[Service]
ExecStart=/root/Bela/projects/OSC2OLED4Bela/OSC2OLED4Bela
Type=simple
Restart=always
RestartSec=1
WorkingDirectory=/root/Bela/projects/OSC2OLED4Bela
Environment=HOME=/root
KillMode=process

[Install]
WantedBy=default.target

                        This can be done from the terminal or by creating a file osc2oled.service in your project (make sure the file includes only the text above and none of the automatically-generated content in the file you create) and then linking it into place by running ln -s /root/Bela/projects/OSC2OLED4Bela/osc2oled.service /lib/systemd/system/osc2oled.service in the Bela IDE console.

                        • start the process in the background with systemctl start osc2oled, stop it with systemctl stop osc2oled.
                        • while running in the background, you can visualise the process's output with journalctl -fu osc2oled (if executing the command from the Bela IDE console, use journalctl -n 20 -u osc2oled | cat instead)
                        • once you verify it is working, you can open a different Bela project and try to send OSC to it from the Bela project instead of the host
                        • once you are happy, you can enable the osc2oled process to start automatically in the background at boot with systemctl enable osc2oled. Later you can disable it with systemctl disable osc2oled
                        • caveat: when running at startup, the osc2oled service will probably start after the Bela program has started, so if you send OSC to it too early when your program starts, some content may not be visualised on the screen.
                          9 days later

                          giuliomoro

                          thanks for the overview! nice one.
                          i got everything working, up to sending OSC from a Pd patch to the background program -
                          but only after referencing the logs and your subsequent answer four posts up.
                          is it possible, for future reference for me and my fellow nitwits, to edit your post some, and have all the relevant info in this one place?
                          to clarify:

                          giuliomoro [Service]
                          ExecStart=/root/Bela/projects/(NAME OF PROJECT)/(NAME OF PROJECT)
                          Type=simple
                          Restart=always
                          RestartSec=1 (<< no need for http://bela.io/ i think?)
                          WorkingDirectory=/root/Bela/projects/(OSC2OLED4Bela or NEW NAME OF PROJECT)
                          Environment=HOME=/root
                          KillMode=process

                          i realise this might all be self-explanatory to some, but it's not to everybody 🙂

                          also

                          giuliomoro Bela IDE console, use journacltl -n 20 -u osc2oled | cat instead)

                          has a typo in journalctl, which is meh if you copy/paste.

                          and last,

                          giuliomoro systemctl enable osc2oled

                          doesn't seem to work with the /***** osc2oled.service *****/ header (generated in the IDE > new file) still on line 1 of the service file. had to remove that, so [unit] was the first thing in there. again, probably obvious to someone who knows what they're doing, but might save some frustration for others.

                          feel free to delete this post after if needed.
                          and thanks for walking us through this!