Hi, this is Wayne again with a topic “Weekend Projects – BeagleBone Audio Looper”.
Hi, i’m marty with make live leaping is a musical performance technique where the artist builds up many different layers of sound in real time in today’s weekend, project by tyler, warman we’ll show you how to use a beaglebone black, a sound card python and pure data to Build an audio looping station which will allow you to build a loop offer the tempo and adjust the loop as it plays. You will need the following parts for this project, most of which can either be picked up at your local radio. Shack or purchased online and you’ll also need the following basic tools: general programming, knowledge and an afternoon to complete the build before we begin. Let’S talk a little bit about the beaglebone black, there have been a few different revisions of this popular board since its release we’ll be using the revision c version if you’re using an older board head on over to the project page, where we’ll show you the extra Steps needed to get started. It’S also where you can learn how to install the peer data project files needed for the build once the beaglebone is configured you’ll need to set up your usb sound card. By default, the beaglebone black uses the hdmi video port to output, sound you’ll need to change the alsa configuration files to the hdmi port and hdmi audio are disabled and the external usb sound card is enabled as the primary sound device once you’ve changed. The configuration save the file plug in the sound card and reboot when it finishes rebooting the sound card power light should light up. Now you can plug in an audio source and headphones to the sound card for testing purposes, try to record a sound and see how it works. You’Ll have to play around with the settings to get it.
Just how you like it. You can read more about all the specific details on the project page once you confirm that everything works it’s time to start working on the enclosure. First, drill three holes in the project box for the dual pole and dual throw switches. Next you’ll wire up all the switches, it helps to label each switch with their functions to help keep track of all the wires.
Next, you can mount the switches in the project box and with a nibbler cut a small hole for the wires to pass through the top of the box, with the beaglebone disconnected and powered down, connect all the wires to the breadboard and beaglebone, along with all the Appropriate resistors, as described on the project page now, you can enable the controls, by powering up the beaglebone and running a few commands via ssh. Once you make. These changes go ahead and check that the beaglebone is reading the pins properly. Next you’ll need to test the looping software clear, the sound by clicking the clear box next set the tempo by pressing the tempo button two times. This sets the tempo by measuring the length between the two presses. Now you can record a sound by clicking the record box, turn the loop on or off by clicking the sound box.
Once you confirm it works, you can load the modified pure data patch called guitar extended lubrical. This version was modified to take input commands from the beaglebone’s pins instead of the check boxes with the graphical user interface you’ll find a link to this file on the project page. Now you can test it out with the switches to do this. Execute the downloaded python script from the command line.
This will read the state of the switches and pass that information onto pure data now start the looper by toggling the play switch to the on position. Toggle the tempo slash timing switch twice to set the timing. The time elapsed between pressing the switch is multiplied by four to set the overall loop length toggle the record switch and record something flip the switch back to neutral. When done then toggle record again to record over the existing loop. Now that you have confirmed that the looper functions properly, the last step is to configure it to run on boot and without the need for a network connection.
You’Ll do this by adding in the configuration file or cron linux’s task scheduler. Once you make that change reboot. The beaglebone and after it’s powered on for a few minutes, the light on the sound card should flash rapidly.
This is the visual indicator that you are ready to loot. This is really just the beginning of what would be a very complex synthesizer in digital looper. Think about how you might add multiple loop channels or utilize, the extra effect positions on the controls or how about adding some leds for visual indication of which channels are leaping be sure to head on over to the project page, to read more about how this sleeper Works and to share your own build ideas until next time. Next time you .