So far, we've bee concentrating on reading the neck of our MIDI bass, by running a resistor ladder up the fingerboard, and shorting one end to ground to read which string is pressing against which fret.
This video popped up on Google+ this morning - it's a follow-up to Jeri Ellsworth's C64 bass video taken at the MakerFaire earlier this year.
https://www.youtube.com/watch?v=_kDhpFaf4EY
We haven't really invested a lot of time into reading when each string is actually plucked, but this video has a great idea in it - simply put a custom shaped piezo in contact between each string and the bridge. It's so simple, it's genius!
Showing posts with label midi. Show all posts
Showing posts with label midi. Show all posts
Monday, July 9, 2012
Friday, June 29, 2012
MIDI saxophone update
After another BuildBrighton meeting last night, a bit more work has been done on MIDI-fying our saxophone. This is now the third attempt and looks the most likely to get a working result! The first time, the wires were ran from the bell to the neck, leaving little or no room for the microcontrotroller circuit. The second time, the wires were run to the bell, so there was a large area we could fill with a circuit board, but the copper-tape-making-contact-with-the-body idea failed on number of pads.
This time, we're sure we've got it right. Only because, we couldn't have come up with a more difficult-to-implement solution! We're (slowly) removing each pad - yes, complete with linkages and springs - and fitting a pushbutton under each one.
In doing this, we're finding out quite a bit about the saxophone.
Namely that it's been badly dropped at some point during it's life, and would be unplayable as an acoustic instrument! There are four or five pads misaligned - and rings on the leather showing where the pad used to sit, and a shallower indent showing it's new resting position after the (presumed) accident.
So despite filling the body with hot glue and generally making a mess of things, at least we can be satisfied in knowing we're not ruining a perfectly good sax for this project - it was only destined for a junk shop somewhere, or an expensive repair job!
When operating the pads, it's interesting to feel the tactile clicky button through the button on the body of the sax. This gives a really nice, responsive feel.
However, some pads are "normally closed" and open when you press a key (or combination of keys) rather than the simpler push-to-close type. We found that sometimes, if you release a key gently, the spring on the pad isn't always strong enough to force the pad fully closed again. Here's an example of one such pad. An extra spring was added between the pad cover and the guard, to help push the pad into it's normally-closed state, and force the pushbutton to "click closed")
This time, we're sure we've got it right. Only because, we couldn't have come up with a more difficult-to-implement solution! We're (slowly) removing each pad - yes, complete with linkages and springs - and fitting a pushbutton under each one.
In doing this, we're finding out quite a bit about the saxophone.
Namely that it's been badly dropped at some point during it's life, and would be unplayable as an acoustic instrument! There are four or five pads misaligned - and rings on the leather showing where the pad used to sit, and a shallower indent showing it's new resting position after the (presumed) accident.
So despite filling the body with hot glue and generally making a mess of things, at least we can be satisfied in knowing we're not ruining a perfectly good sax for this project - it was only destined for a junk shop somewhere, or an expensive repair job!
(Saxophone fitted with five pushbuttons, mounted into acrylic disks. The push buttons are the slightly clicky tactile ones and the guard has been removed to allow the pads to open more fully).
However, some pads are "normally closed" and open when you press a key (or combination of keys) rather than the simpler push-to-close type. We found that sometimes, if you release a key gently, the spring on the pad isn't always strong enough to force the pad fully closed again. Here's an example of one such pad. An extra spring was added between the pad cover and the guard, to help push the pad into it's normally-closed state, and force the pushbutton to "click closed")
Sunday, June 24, 2012
BuildBrighton MIDI Workshop
We had a great time over the weekend at the BuildBrighton MIDI workshop.
Not only did we cover the basics of Arduino programming, but there was even time to go through some electronics fundamentals - switches, resistors, potentiometers, voltage dividers and more!
The afternoon session was pretty awesome - once we'd de-mystified the MIDI protocol (note on, note off messages plus some excellent midi-thru examples from Jason, creating chord builders and arpeggiators) we got down to the serious business of making some noise!
It'd be great to say we had a jam and made some music, but we didn't really get much further than making cool noises, chord changes and whooshing arpeggios. But everyone on the course came up with their own unique ideas for implementing MIDI. At the start of the day, the most ambitious idea was a keyboard synth clone or a midi drumkit.
After the workshop, people were talking about light-to-sound modules, interactive art installations - even MIDI Flip-Flops. That's what the workshop was really always about!
Not only did we cover the basics of Arduino programming, but there was even time to go through some electronics fundamentals - switches, resistors, potentiometers, voltage dividers and more!
The afternoon session was pretty awesome - once we'd de-mystified the MIDI protocol (note on, note off messages plus some excellent midi-thru examples from Jason, creating chord builders and arpeggiators) we got down to the serious business of making some noise!
It'd be great to say we had a jam and made some music, but we didn't really get much further than making cool noises, chord changes and whooshing arpeggios. But everyone on the course came up with their own unique ideas for implementing MIDI. At the start of the day, the most ambitious idea was a keyboard synth clone or a midi drumkit.
After the workshop, people were talking about light-to-sound modules, interactive art installations - even MIDI Flip-Flops. That's what the workshop was really always about!
(Jason in action during the BuildBrighton MIDI workshop, untangling a rat's nest of wires)
Thursday, June 21, 2012
MIDI sax
It's late and it's Thursday, which can only mean it's BuildBrighton night again.
We've been busy working on our MIDI saxophone, trying to get it ready for next Saturday's MIDI workshop. Sadly, despite a promising start, it looks like we're going to miss the deadline. Here's why:
The original idea was to use copper tape on the insides of each pad and run a wire to a microcontroller. By detecting which pads were open and closed (copper tape touching the grounded body of the sax where the pad was closed would pull an input pin low, whereas an input pin linked to an open pad would be pulled high by a pull-up resistor) we could work out which note was being fingered, and play the appropriate note.
Sometimes it was necessary to add a little extra tape to the back of the pads, to stop the weight of the wire pulling the copper tape free. The copper tape is very sticky, but despite this, sometimes would start to peel away from the end where the wire met the centre of the pad.
With the first few pads, everything worked according to plan (with the exception that we had to file a little bit of lacquer away from the very rims of the sound holes, so that the copper tape could touch something metallic/conductive to make the circuit)
After completing the first few pads, we stopped and thought about where these inputs were going to. So far, we'd wired the entire instrument from the pads to the top of the instrument neck. This was a very small opening into which we needed to fit our microcontroller.
It was only when someone pointed out that we'd also have to use very small batteries that we realised our mistake! Instead of taking the wires to the top of the neck of the instrument, we'd have a lot more room (and could make accessing the battery compartment much easier) if we put the microcontroller onto a board and used it to "plug" or cover the opening of the larger bell part of the sax. D'oh.
It took just three minutes to undo about three days wiring work. But less than an hour to wire the first few pads up "properly".
As each wire went in, we closed the pad it was connected to, and tested for continuity between the end of the wire and the body of the instrument. This proved that the pad opening and closing could be used on an input pin of our microcontroller. All went well for the first six pads......
The seventh pad (on the left, below) was a bit more problematic.
This particular pad was not pressed directly by the player pressing a button, but was closed by a linkage from one of the other pads. As a result, it didn't quite have the same pressure upon it.
This was compounded by the face that this particular pad had a slight leak - it didn't sit exactly flush over the opening. When played as an acoustic instrument, this leak would cause the instrument to sound out-of-tune.
A more immediate problem for us is that because of where the tape sits inside the pad (sometimes fitting the copper tape to the underside of the pad is a tight squeeze and we can't always put it where we'd like) when this pad is pulled closed by the linkage, we're not getting the input signal going low.
It seems that, although relatively easy to implement, our copper tape idea needs a bit of a rethink......
We've been busy working on our MIDI saxophone, trying to get it ready for next Saturday's MIDI workshop. Sadly, despite a promising start, it looks like we're going to miss the deadline. Here's why:
The original idea was to use copper tape on the insides of each pad and run a wire to a microcontroller. By detecting which pads were open and closed (copper tape touching the grounded body of the sax where the pad was closed would pull an input pin low, whereas an input pin linked to an open pad would be pulled high by a pull-up resistor) we could work out which note was being fingered, and play the appropriate note.
Sometimes it was necessary to add a little extra tape to the back of the pads, to stop the weight of the wire pulling the copper tape free. The copper tape is very sticky, but despite this, sometimes would start to peel away from the end where the wire met the centre of the pad.
With the first few pads, everything worked according to plan (with the exception that we had to file a little bit of lacquer away from the very rims of the sound holes, so that the copper tape could touch something metallic/conductive to make the circuit)
After completing the first few pads, we stopped and thought about where these inputs were going to. So far, we'd wired the entire instrument from the pads to the top of the instrument neck. This was a very small opening into which we needed to fit our microcontroller.
It was only when someone pointed out that we'd also have to use very small batteries that we realised our mistake! Instead of taking the wires to the top of the neck of the instrument, we'd have a lot more room (and could make accessing the battery compartment much easier) if we put the microcontroller onto a board and used it to "plug" or cover the opening of the larger bell part of the sax. D'oh.
It took just three minutes to undo about three days wiring work. But less than an hour to wire the first few pads up "properly".
As each wire went in, we closed the pad it was connected to, and tested for continuity between the end of the wire and the body of the instrument. This proved that the pad opening and closing could be used on an input pin of our microcontroller. All went well for the first six pads......
The seventh pad (on the left, below) was a bit more problematic.
This particular pad was not pressed directly by the player pressing a button, but was closed by a linkage from one of the other pads. As a result, it didn't quite have the same pressure upon it.
This was compounded by the face that this particular pad had a slight leak - it didn't sit exactly flush over the opening. When played as an acoustic instrument, this leak would cause the instrument to sound out-of-tune.
A more immediate problem for us is that because of where the tape sits inside the pad (sometimes fitting the copper tape to the underside of the pad is a tight squeeze and we can't always put it where we'd like) when this pad is pulled closed by the linkage, we're not getting the input signal going low.
It seems that, although relatively easy to implement, our copper tape idea needs a bit of a rethink......
MIDI bass frets
There's something not quite right with our laser printer.
It seems to be printing bitmaps at about 95% of full size.
We made up a couple of frets for our MIDI bass and allowed a generous border around each piece (so it can be cut/sanded/filed to an exact fit after being mounted onto the guitar neck)
The only thing is, that even allowing for this relatively large border around each piece, they are only just the right size to go on the fingerboard.
Here are some surface-mount resistors connected onto each section of fingerboard. These boards will be mounted face down onto the neck. The pads on the edges of each board will be connected by strips of copper tape, running under one, over the top of the (plastic, non-conductive) fret between the two, and joining the pads on the next section of fingerboard. By doing this, we can create a resistor ladder for each string along the length of the guitar neck.
It seems to be printing bitmaps at about 95% of full size.
We made up a couple of frets for our MIDI bass and allowed a generous border around each piece (so it can be cut/sanded/filed to an exact fit after being mounted onto the guitar neck)
The only thing is, that even allowing for this relatively large border around each piece, they are only just the right size to go on the fingerboard.
Here are some surface-mount resistors connected onto each section of fingerboard. These boards will be mounted face down onto the neck. The pads on the edges of each board will be connected by strips of copper tape, running under one, over the top of the (plastic, non-conductive) fret between the two, and joining the pads on the next section of fingerboard. By doing this, we can create a resistor ladder for each string along the length of the guitar neck.
Arduino MIDI playground boards
In preparation for the BuildBrighton Midi Workshop this weekend, we've been busy etching and making up boards for the attendees to use with their Arduino microcontrollers.
These take the form of "shields" which sit on top of the main Arduino board.
Jason did a great job designing the circuit and PCB and Steve really made them look the business with his custom silkscreen/sticker job.
After etching and drilling, the stickers had to be carefully lined up. The easiest way to do this was to hold the board up against a bright light, and apply the sticker, taking care to get the pin holes shining through from the back into the correct places on the sticker front.
To make adding the components easier, we used a drawing pin to prick a small hole in the sticker at each point where a hole had been drilled on the PCB. The end result was quite impressive!
After populating and soldering all the components onto the board(s) they're finally ready for testing before the big day. We wanted to make sure that we spent as much time as possible working around MIDI and actually creating something like an instrument, rather than lose half-a-day or more running a soldering workshop, so each lucky attendee will get a pre-made MIDI shield as part of their day's training.
Included on each board are
Opto-isolator (to conform with the MIDI specification)
4 x pushbuttons
8 x LEDs
1 x potentiometer (variable resistor)
1 x LDR (light dependent resistor)
1 x MIDI in DIN socket
1 x MIDI out DIN socket
Through headers to allow boards to be stacked on top of each other
1 x jumper to disconnect the LEDs to allow the digital output pins on the Arduino to be re-purposed
All in all, making the boards has been a lot of work, but we think they're worth it. They look really impressive when soldered up, and we're looking forward to seeing what ideas other people can come up with for them.
These take the form of "shields" which sit on top of the main Arduino board.
Jason did a great job designing the circuit and PCB and Steve really made them look the business with his custom silkscreen/sticker job.
After etching and drilling, the stickers had to be carefully lined up. The easiest way to do this was to hold the board up against a bright light, and apply the sticker, taking care to get the pin holes shining through from the back into the correct places on the sticker front.
To make adding the components easier, we used a drawing pin to prick a small hole in the sticker at each point where a hole had been drilled on the PCB. The end result was quite impressive!
After populating and soldering all the components onto the board(s) they're finally ready for testing before the big day. We wanted to make sure that we spent as much time as possible working around MIDI and actually creating something like an instrument, rather than lose half-a-day or more running a soldering workshop, so each lucky attendee will get a pre-made MIDI shield as part of their day's training.
Included on each board are
Opto-isolator (to conform with the MIDI specification)
4 x pushbuttons
8 x LEDs
1 x potentiometer (variable resistor)
1 x LDR (light dependent resistor)
1 x MIDI in DIN socket
1 x MIDI out DIN socket
Through headers to allow boards to be stacked on top of each other
1 x jumper to disconnect the LEDs to allow the digital output pins on the Arduino to be re-purposed
All in all, making the boards has been a lot of work, but we think they're worth it. They look really impressive when soldered up, and we're looking forward to seeing what ideas other people can come up with for them.
Monday, June 11, 2012
MIDI bass frets - exploded view
Here's a quick diagram showing how our MIDI bass fret system works.
We've already removed the fingerboard off our bass guitar, and plan to replace it entirely with home-made circuit boards (each section between two frets is a separate PCB).
The pcbs are fixed to the guitar neck, screwed down on top of some sections of rubber padding. This serves two purposes. The first thing it does is create a "pocket" for the surface-mount electronics on the PCB to comfortably fit without getting damaged. Secondly, it pushes back against the board mounted upon it.
This allows us to use copper table, placed over the fret (each fret is a piece of laser-cut acrylic) to create a single, continuous circuit up the entire length of the neck.
For each guitar string, the circuit is simply a resistor and LED, so each PCB has four resistors and four LEDs (one for each string)
We've already removed the fingerboard off our bass guitar, and plan to replace it entirely with home-made circuit boards (each section between two frets is a separate PCB).
The pcbs are fixed to the guitar neck, screwed down on top of some sections of rubber padding. This serves two purposes. The first thing it does is create a "pocket" for the surface-mount electronics on the PCB to comfortably fit without getting damaged. Secondly, it pushes back against the board mounted upon it.
This allows us to use copper table, placed over the fret (each fret is a piece of laser-cut acrylic) to create a single, continuous circuit up the entire length of the neck.
For each guitar string, the circuit is simply a resistor and LED, so each PCB has four resistors and four LEDs (one for each string)
BuildBrighton midi workshop
Over at BuildBrighton, we're working on putting together a make-your-own-MIDI-instrument workshop to teach people the core basics of MIDI messaging and how to send and receive MIDI commands. As part of the workshop, we'll be providing all attendees with an Arduino shield with some buttons, LEDs, volume/pitch bend pot and more.
Using a mixture of press-n-peel blue and the cheap Chinese alternative, we've managed to toner transfer about 20 boards.
After a marathon etching session (about three hours!) here are no less than sixteen boards (the final three boards were still etching when this photo was taken)
As the workshop is just a few weeks away (on Saturday 23rd June) we've got some boards to make up!
Which means the nerd session or two is going to be taken up etching and drilling PCBs.
Using a mixture of press-n-peel blue and the cheap Chinese alternative, we've managed to toner transfer about 20 boards.
After a marathon etching session (about three hours!) here are no less than sixteen boards (the final three boards were still etching when this photo was taken)
All we need now are some spanky cool looking stickers (for the component side) from Robot Steve then we can drill and populate the boards next Thursday night.
Saturday, June 9, 2012
MIDI bass fret setup
We're replacing the entire fingerboard for our MIDI bass, and replacing it with a number of PCB sections. We're basically creating a resistor ladder on the underside of the fingerboard, for each string on the guitar. The idea is that the resistor ladder creates a voltage divider and we take an analogue input from the resistor network into the PIC microcontroller
If all the strings are connected to ground, and all the frets on the fingerboard are connected at different points along the resistor ladder, we should be able to tell which fret the string is being pressed against, and therefore which note to play.
In the example above, if the (grounded) string was held on the second fret, the total resistance between the nut end of the board and the input pin would be quite high - so the voltage divider creates a high voltage on the input pin.
But if the player holds the (grounded) string on, say, the 18th fret, the 5v going through the resistor network goes through fewer resistors between the input pin and ground, causing the voltage on the input pin to drop. With clever use of resistor values, we should be able to create a look-up table in firmware such that we know instantly which string is being held against which fret. No more latency issues trying to sample and decode the frequencies that the strings are vibrating at!
If all the strings are connected to ground, and all the frets on the fingerboard are connected at different points along the resistor ladder, we should be able to tell which fret the string is being pressed against, and therefore which note to play.
In the example above, if the (grounded) string was held on the second fret, the total resistance between the nut end of the board and the input pin would be quite high - so the voltage divider creates a high voltage on the input pin.
But if the player holds the (grounded) string on, say, the 18th fret, the 5v going through the resistor network goes through fewer resistors between the input pin and ground, causing the voltage on the input pin to drop. With clever use of resistor values, we should be able to create a look-up table in firmware such that we know instantly which string is being held against which fret. No more latency issues trying to sample and decode the frequencies that the strings are vibrating at!
Friday, June 8, 2012
MIDI bass instrument
As we haven't got everything quite to hand to finish off our multi-effect pedal circuit, and with Thursday being the regular BuildBrighton meet-up, we needed something else to work on. And, having access to a full equipped workshop with some really cool tools, it wasn't time to play about with resistors and microchips - we needed to do something BIG!
As we're working on some MIDI Arduino shields for an up-and-coming MIDI workshop, it made sense to work on a MIDI instrument. But exactly what?
We've already spent some time considering making a midi guitar - where the input from the strings against the frets is converted into a midi signal and fed into a synth. A few years we tried this, taking the audio output from the jack socket on the instrument, and analysing it to try to work out which note(s) were being played.
It turns out that this is very difficult.
To try to simplify things, we looked into making individual string pickups (so each string has it's own signal to analyse instead of trying to work out which chord is being played across all six strings!). This is exactly how the Roland's GK-3 "divided pickup" works. The signal from each string is sampled and an output value given to a different channel. The only problem with this approach is that there's a noticeable delay between plucking the string and the sound being played. It gets worse with lower notes and makes a bass guitar almost unplayable!
So we're back to using the contact of the strings against the frets as our signal, which removes the need to analyse the audio output. We started by:
Removing the traditional fingerboard from a bass guitar. This was quite easy (once we decided we'd never want to reuse the original fingerboard). Just plenty of heat from a hot gun, and some levering with a couple of screwdrivers.
It actually took three of us to do this! The neck was removed from the body and one person held it with one hand while hacking at it with a screwdriver with the other hand. The second person also levered away with a screwdriver, while the third waved the hot gun up and down the neck of the guitar. It took less than 10 minutes to remove the fingerboard!
(the scorch marks on the neck will be sanded out when we come to finish the instrument!)
With the fingerboard removed, it was time to design a replacement.
We're going to be making the replacement fingerboard from copper clad board, cut into sections, with an acrylic fret (3mm) between each one.
The first fret of the bass was measured as 46.5mm long.
Given that the length of a guitar string is exactly half one octave higher (i.e. the string length when the 12th fret is played is exactly half the string length of the open low E string) we came up with the following formula:
Length of next fret = length of previous fret / (2^ 1/12)
where 2^(1/12) is two to the power of one over twelve.
We made a cardboard template to try the idea out:
By the time we'd reached the end of the neck, we had 23 frets.
The original bass had only 22 so it looks like our original measurement on the first fret was a little out. However, it's still within a reasonable distance to recreate the original bass "feel" when playing.
Exact length isn't critical because we're never going to be playing the bass "acoustically" - our replacement frets will actually be switches, activated by the string being pressed against them. More details in the following post(s).....
As we're working on some MIDI Arduino shields for an up-and-coming MIDI workshop, it made sense to work on a MIDI instrument. But exactly what?
We've already spent some time considering making a midi guitar - where the input from the strings against the frets is converted into a midi signal and fed into a synth. A few years we tried this, taking the audio output from the jack socket on the instrument, and analysing it to try to work out which note(s) were being played.
It turns out that this is very difficult.
To try to simplify things, we looked into making individual string pickups (so each string has it's own signal to analyse instead of trying to work out which chord is being played across all six strings!). This is exactly how the Roland's GK-3 "divided pickup" works. The signal from each string is sampled and an output value given to a different channel. The only problem with this approach is that there's a noticeable delay between plucking the string and the sound being played. It gets worse with lower notes and makes a bass guitar almost unplayable!
So we're back to using the contact of the strings against the frets as our signal, which removes the need to analyse the audio output. We started by:
Removing the traditional fingerboard from a bass guitar. This was quite easy (once we decided we'd never want to reuse the original fingerboard). Just plenty of heat from a hot gun, and some levering with a couple of screwdrivers.
It actually took three of us to do this! The neck was removed from the body and one person held it with one hand while hacking at it with a screwdriver with the other hand. The second person also levered away with a screwdriver, while the third waved the hot gun up and down the neck of the guitar. It took less than 10 minutes to remove the fingerboard!
(the scorch marks on the neck will be sanded out when we come to finish the instrument!)
With the fingerboard removed, it was time to design a replacement.
We're going to be making the replacement fingerboard from copper clad board, cut into sections, with an acrylic fret (3mm) between each one.
The first fret of the bass was measured as 46.5mm long.
Given that the length of a guitar string is exactly half one octave higher (i.e. the string length when the 12th fret is played is exactly half the string length of the open low E string) we came up with the following formula:
Length of next fret = length of previous fret / (2^ 1/12)
where 2^(1/12) is two to the power of one over twelve.
We made a cardboard template to try the idea out:
By the time we'd reached the end of the neck, we had 23 frets.
The original bass had only 22 so it looks like our original measurement on the first fret was a little out. However, it's still within a reasonable distance to recreate the original bass "feel" when playing.
Exact length isn't critical because we're never going to be playing the bass "acoustically" - our replacement frets will actually be switches, activated by the string being pressed against them. More details in the following post(s).....
Sunday, June 3, 2012
MIDI saxophone
This rather tongue-in-cheek article (http://www.mindworkshop.com/saxophone.html) explains how I feel about learning saxophone. I bought one a few years ago, even took a few lessons, learned a few songs, but then put it back in it's case, where it's stayed ever since.
Why? I guess I'm just too considerate!
I didn't like the idea of my neighbours having to listen to the squeaks and farts that came out of the shiny bendy bit day and night, and the cost of going to someone else's house to learn and practice become prohibitive quite quickly. So I figured that one day I'd build a practice sax, that would let me learn the fingerings and notes without having to blow the thing too loudly.
That was four or five years ago.
My lovely saxophone was too nice (and too expensive) to hack, so every now and again I'd check eBay for a cheap instrument. Well, this morning, all that waiting finally paid off
Here's my new sax, ready to be fitted with a load of wires to be converted into a midi instrument. My first idea was to run some CAT5 cable through the body, then separate the wires afterwards. This very quickly proved too difficult
So I separated the cable into individual strands and placed a small weight (capacitor) at one end of each wire.
I then pushed the capacitor through an open, erm, valve? pad? hole? and wiggled it round, while feeding the wire into the body of the sax.
Eventually it appeared at the neck end of the instrument (I started feeding the wire into the larger holes in the curved bit at the bottom of the bell and worked up the instrument)
Sometimes - especially once a few wires were in place - the cap got caught up with other wires or fell into the hole of another note. If it couldn't be shaken free, a bent bit of solid-core wire was easily pushed down the next to hook it free and retrieve the other end of the wire.
After about an hour of wire-wiggling, I managed to get twelve wires from the lower 12 holes, through the instrument body and secured out of the top of the neck. Once all 24 are in place (the body has 23 holes and a 24th on the crook of the mouthpiece) then can be soldered to a PCB and hooked up to a PIC microcontroller for the MIDI fun to begin!
Why? I guess I'm just too considerate!
I didn't like the idea of my neighbours having to listen to the squeaks and farts that came out of the shiny bendy bit day and night, and the cost of going to someone else's house to learn and practice become prohibitive quite quickly. So I figured that one day I'd build a practice sax, that would let me learn the fingerings and notes without having to blow the thing too loudly.
That was four or five years ago.
My lovely saxophone was too nice (and too expensive) to hack, so every now and again I'd check eBay for a cheap instrument. Well, this morning, all that waiting finally paid off
Here's my new sax, ready to be fitted with a load of wires to be converted into a midi instrument. My first idea was to run some CAT5 cable through the body, then separate the wires afterwards. This very quickly proved too difficult
So I separated the cable into individual strands and placed a small weight (capacitor) at one end of each wire.
I then pushed the capacitor through an open, erm, valve? pad? hole? and wiggled it round, while feeding the wire into the body of the sax.
Eventually it appeared at the neck end of the instrument (I started feeding the wire into the larger holes in the curved bit at the bottom of the bell and worked up the instrument)
Sometimes - especially once a few wires were in place - the cap got caught up with other wires or fell into the hole of another note. If it couldn't be shaken free, a bent bit of solid-core wire was easily pushed down the next to hook it free and retrieve the other end of the wire.
After about an hour of wire-wiggling, I managed to get twelve wires from the lower 12 holes, through the instrument body and secured out of the top of the neck. Once all 24 are in place (the body has 23 holes and a 24th on the crook of the mouthpiece) then can be soldered to a PCB and hooked up to a PIC microcontroller for the MIDI fun to begin!
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