Project Logs

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• Project Log #15 Version 5 finally built using the PCB's

  XenonJohn • 05/19/2020 at 17:44 • 0 comments

  Have been involved in a ventilator project but finally got around to making a few of the V5 DigiGurdy's which have a custom PCB inside onto which everything connects. Also has the unpluggable Teensy 3.5 on the front under a white 3D printed cover. I have made 2 videos describing everything about this version, see below. All white / aluminium and now using white laser cut acrylic for the front and rear surfaces. I have made 7 so far.

  DigiGurdy Jenga.

  This is 15min long but explains just about everything. The screen flicker on the display is due to my GoPro camera, it does not flicker in real life !

• Project Log #14: PCB's have arrived for latest version

  XenonJohn • 04/26/2020 at 23:26 • 1 comment

  This is a very quick update. 

  20 PCB's have arrived from China which I can solder the microswitches to and also 2 rows of pin headers to allow the Teensy board to be plugged into the FRONT of the DigiGurdy. 

  The whole machine will be white as in the left-hander featured in Project Log 12b.

  The Teensy will have a small 3D printed removable plastic cover. This allows it to be unplugged and sent to me if not an Arduino enthusiast so I can mail it back to you with a software upgrade.

  It also allows an SD card to be slid into the end of it, should I wish to use that for something - working on it. For those who have suggested I design a custom board with WiFi connectivity for software upgrades, my answer would be that to do that I would have to employ someone and unless making 1000 of them, not much point. As it is I paid someone to design this PCB.

  It does speed up the build time considerably and is much neater.

  Other project taking up 99% of my time right now but I thought I would put one of these together just to check that it works - which it does.

  Photos below, just the electronics assembled for testing purposes.

  The USB lead will be held captive in the slot cut for it by the cover which will enclose the Teensy and this cable.

• Project Log 12b: Version 4, neater & easier to construct

  XenonJohn • 03/06/2020 at 22:18 • 0 comments

  Version 4

  - Many software improvements based on suggestions from Nigel Eaton, David Jacobs and others.

  - Have sorted out a reasonable set of tuning options. Startup menu gives you 6 tuning options. Trying to offer a reasonable selection for the more experienced, but not an overwhelming set of options for the beginner either. Select one and it will then show you how to set up the FluidSynth app on your phone so it all works correctly and sounds as it should. The software does not "know" how you have set up the phone app so this is the easiest way to set both up so they work with each other.

  - Many changes to the 3D prints so the whole thing holds itself together just using the 4 long screws at each end.

  - Alloy channel now runs the full length of the device, enclosing the larger gearmotor crank mechanism.

  - Using white laser cut acrylic panels rather than plywood.

  - White USB cable.

  - Going for an aluminium and white plastic effect, rather like an *pple product.

  - 6th tuning option allows you to set it up as a Tenor gurdy.

  These are all shown in the video below. Please note in the video below I am demonstrating them on a LEFT-handed version i.e. back to front !

  To come.......

  I am awaiting imminent arrival of some printed circuit boards onto which the microswitches will be soldered directly. This will eliminate most of the internal wiring and simplify the build further.

• Project log #12: Stronger Crank and many code changes

  XenonJohn • 01/24/2020 at 14:26 • 0 comments

  List of changes to original version based on feedback from a couple of early users:

  1) Much stronger crank mechanism based around a larger gearmotor in new 3D printed enclosure with a 6mm shaft. The bulb has been removed as if it blew, the system would not work as intended. Replaced with wire-wound resistor bridge. 

  2) No run-on when you stop cranking. Originally this was intended to help beginners as it would sound even if you momentarily stopped cranking.

  3) Keys do not play at all unless you are either cranking or have pressed the gaming FIRE button.

  4) Drones did not sound right in previous code when using tuning other than G/C. As the DG code has to be aware of your selected drones on the FluidSynth app on the connected smartphone, this has been addressed by the OLED screen offering you 4 tuning options on startup. Once you select one, it then tells you what drones to select within FluidSynth. This keeps it all working correctly. Tunings are: melody G / Playing in key of G;  melody G / playing in C;  melody D / playing in D;  melody D / playing in G. Trying to keep beginners from information overload but also keep more experienced users moderately happy.

  5) If you intermittently crank with a note key held down, it will sound the note each time, in previous code you had to release and re-depress the key.

  6) In new FluidSynth soundfont (V10 onwards) I have added larger choice of different loudness buzz sounds and keyclick sounds. PM me for the soundfont. I will send by wetransfer as large file.

  7) Repeat MIDI - off commands being sent out on some channels have been much reduced. With FluidSynth these were not noticeable but if attached to a more sophisticated synthesiser program running on a laptop, this could produce problems.

• Project Log #11: More design tweaks and assembling the first six.

  XenonJohn • 11/24/2019 at 15:19 • 0 comments

  I am assembling six DG's for some brave early adopters out there. 

  A few design changes: 

  i) On startup the software measures the voltage on the analog pin from the buzz-sensitivity potentiometer 200 times and calculates the standard deviation. If low, a crank module is present and if large it is not. This means I can use same software for both variants of the design. I have added a gaming button to the crank module now instead of a small switch, so you can play it by tuning the crank, or by pressing this button with right hand. If you want to remove the crank module at some point in the future, you can unbolt it, remove the glowing glass dome and remount the switch from the crank module into the hole where the glass dome was (it will fit exactly). Screw on an end blanking plate, which will be supplied and the machine will then work again just fine in crankless mode with no software changes required.

  ii) In demonstration mode there are now 22 songs.

  iii) Some changes to the code have been made allowing the crank buzz to operate a little more like the real thing.

  iv) Acetone polishing of the 3D printed keys: I want the stems to remain unchanged as they fit the slots in the wooden laser cut panels perfectly, but I do want the key ends to be smooth and shiny, i.e. I want to acetone vapour polish the ends of the keys only. The solution is to wrap the stems in aluminium foil before placing them into my vapour chanber.

  Despite using laser cut panels to reduce the amount of 3D printing, as you can see I have been on a 3D printing-fest for the past 3 weeks to produce all the parts required.

  Have experimented with various pushbuttons, the gaming ones work best.

  Just some of the acetone polished keys.

  Some of the laser cut panels.

  End structures and crank housings, printed and acetone polished.

  Six sets of microswitches mounted and wired up to Teensy boards along with the OLED screens.

  Key-Henge. My acetone polishing rig. The felt is soaked with acetone and held to inside of glass bell with magnets.

  Some nice potentiometers with gold anodized knobs.

  Alloy extrusions all cut to length.

  Fishing reel handles from China.

  Better photo of the acetone polishing rig.

  Self contained crank module wiring now has multi-pin plug to connect it to main body of the DG.

  Bags and bags of 3D printed upper and lower keys, all of which are in the acetone polishing queue!

• Project Log #10: New Build Videos 21/10/19

  XenonJohn • 10/21/2019 at 22:51 • 2 comments

  Here are some new build videos (in 2 parts as YouTube only allow a max video length of 15min. This is the new hybrid version made from laser cut 3mm ply, aluminium extrusions and 3D printed parts. The version shown here is the basic one without the crank module.

• Log #9: Redesign using laser cut ply to reduce 3D printing

  XenonJohn • 10/20/2019 at 21:50 • 0 comments

  October 2019: REDESIGN IS COMPLETE using laser cut ply for the front and rear panels to reduce the amount of 3D printing required somewhat, to reduce overall build time and also to reduce the time spent filing and fettling the keys, keyslots and so on to make everything fit and work smoothly.

  The set of files I have just uploaded all refer to this easier to build crankless version. All the information is there for you to build one. This has an arcade FIRE button on the front right hand surface. Just hold the right hand end in your right hand, press this button with your middle 2 fingers; the drones and open melody string will sound as if you had started to turn the crank, then you start playing.

  - A small amount of filing of the keys may be required but the laser cut ply parts require none at all.

  - The keys can easily be renewed if you break one.

  - Rear ends of the keys project from rear of keybox in a way more similar to a real HG.

  - Keys shaped to hit front deck just before the maximum microswitch travel is reached. This should better protect the microswitches if played too hard.

  I am working on a version of this with the previously described crank module. The build for that version will be 95% the same as this i.e. the extra wiring for the bolt-on crank module and slightly different code.

  The play button does not have to be lime green, they come in many other colours!

  Next project log will feature the crank version of this new design.

• Log #8: Different tunings enabled & feature in "Prog" magazine

  XenonJohn • 09/13/2019 at 14:13 • 0 comments

  Short update:

  I have improved the software so now you can select either of the two commonest tunings for the keyboard i.e. G/C or D/G. You can select the one you want on startup and also change the tuning while the device is in operation by pressing the upper rightmost three keys simultaneously. It is a bit like a Tesla car, load in a software upgrade and your (unchanged) hardware suddenly performs better.

  I have uploaded this version of the code (Version 37).

  Also the original red plastic DigiGurdy has to my surprise been featured in the current edition of Prog magazine - as in Prog Rock. Aug/September 2019.

  I intend to go through all the 3D print files one more time then will also post them up here.

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

  XenonJohn • 08/23/2019 at 23:30 • 3 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.

• Log #6: Fully Assembled With Crank Module

  XenonJohn • 08/19/2019 at 20:56 • 0 comments

  Here is the DigiGurdy coming together at last, with the crank simulator module attached. This video clip gives an overview of the functions of the device from the point of view of a user and also shows how you select and play songs in demonstration mode. I will add a more detailed video at some point showing you how to get the soundfont onto your phone and set it up to play the sounds correctly with the current version of the DigiGurdy. In this update video you can see:

  - Crank operated drones and open melody string.

  - Crank operated buzzing sound (sound audio file supplied by Nigel Eaton, many thanks).

  - More realistic key-click sounds

  when the keys are pressed.

  - Use of a control knob to adjust the sensitivity of this buzzing rhythm sound when cranking to suit your own style of playing.

  - Blue orb on front panel which glows when turning the crank.

  - Demonstration of the crank-override switch which allows you to practice the melody without need to turn the crank.

  - Demonstration mode is shown being used with user-selection of songs and playback speed.

  The whole assembly is held together with just 4 long screws at each end. Almost no adhesives are required apart from where the screen is held in position.

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