Log #7 How to connect to phone and use Fluidsynth to create music

A project log for The Digi-Gurdy

MIDI based electronic portable practice hurdy-gurdy.

XenonJohnXenonJohn 08/23/2019 at 23:303 Comments

This video update shows how you use a phone to play the MIDI data coming out of the DigiGurdy.

The soundfont file (.sf2 format) has to have been uploaded onto the phone in advance. I will make this file available soon. All the sounds to be played are stored in this file.

The MIDI player I am using is called FluidSynth and is available free from the Google Play store for Android phones. An Apple version also exists but I have not tried it with the DigiGurdy.

The DigiGurdy outputs data on 5 MIDI channels. In FluidSynth we must assign an instrument or sound to each of these 5 channels for it to work correctly. This is best explained with a video and so the video below shows me setting up Fluidsynth on a phone in this way. FluidSynth has a very basic user interface but it also has very low latency (time between pressing a key and hearing the sound) and so works well with the DigiGurdy.


XenonJohn wrote 08/24/2019 at 21:53 point

Good ideas. I have written a few Android apps the cheat way using MIT App Inventor II. I did consider a phone holder of some sort actually on the DigiGurdy itself but for now the phone holder that clips to the edge of a table works quite well. It is actually designed for the front edge of car dashboards. Is there any variant of FluidSynth out there with a nicer user interface by any chance, or one that can just remember your last-used setup? That would be quite useful.

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Craig Hissett wrote 08/24/2019 at 23:42 point

Ah yes, I've messed about with App Inventor, but never done a trying worthwhile with it. I'm becoming quite handy with Visual Studio at work so I will probably go that way :)

I haven't come across any android based variants I'm afraid. There's some useful python code that works with Fluidsynth; it wouldn't take too much to whack a Pi into the project and create a web-based GUI?

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Craig Hissett wrote 08/24/2019 at 00:15 point

I'm a big fan of fluidsynth on android. I've used it to test resding drum pads on my drum controller project, and I'm contemplating using it within my Wi-Fi trombone project too; connect an old phone to the arduino controlling the slide and sensor readings, then use the phone's audio output to run to some more powerful speakers.

If i build the phone into the back of the trombone it'll give a nice easy interface for changing sounds and suchlike. It also opens the door to an android app being written to manipulate the Arduino settings via the serial connection.

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