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Cheaper Bluetooth option
#1
Following a couple of requests about converting a USB pedalset to Bluetooth, I thought I'd show how I did it.

Being a cheapskate, I had originally opted to use a USB pedal, as they were a lot cheaper (and, I suspected, more reliable).
However, continual plugging and unplugging of my pedals seems to wear out the connector and I began to realise there were
some advantages in having a wireless solution. Commercial pedals are not cheap, so I thought it might be a good idea to start
off with what I already had and see how it went.

Up until now, I have been using a three pedal unit like this one - http://imageshack.com/i/eyWhSoUFj - these are on the net
at around the €20 mark. Actually, they work well, but my problem was the connectors on my tablet, they are really poor
mechanically and have become very intermittent over the past 18 months.

Initially, I started off with the idea of modifying a Bluetooth mouse, but I had a lot of problems with these things timing
out and that was something for which I never found a solution.  Someone else on the forum had already mentioned the Adafruit
EZ-Key - https://www.adafruit.com/product/1535 - and this seemed like a good starting point, so I bought one.
Having received the EZ-Key module, I set about modifying the pedals.

The EZ-Key runs on anything from a 3v supply upwards.  I use 3.7 volt lithium batteries to power my Casio midi guitar, so I
already had a number of these to hand.  One AA size battery is sufficient to power the EZ-Key.  I needed something to house
both the electronics and the power supply, so I purchased a switched 3AA battery holder - http://imageshack.com/i/paCkuLwwj -
modified as follows.

As supplied, the battery holder looks like this - http://imageshack.com/i/exWdgsuGj - and my first move was to alter it to
accept a single AA cell.  This was quite easy, all that was needed was to remove the connecting links between the separate
compartments, cutting one in half to provide the positive connector for the single battery compartment that was left -
http://imageshack.com/i/ipluJWV9j . The positive connector that remained was a little 'loose', but I decided that the spring
of the negative connector was enough to keep the whole thing in place. You could glue it in place, if you really thought it
was necessary. 

A quick check with a voltmeter was made - http://imageshack.com/i/idJP2eH2j - just to make sure the power (and switch) worked
as expected.

Next, I removed the wall between the remaining two battery compartments (easy to do, using a pair of side-cutters) to make a
space for the EZ-Key module - http://imageshack.com/i/exq1MkyDj .

Setting aside the battery holder, I turned my attention to the pedals themselves.  The wiring between the individual pedals
is underneath and covered with a piece of sticky tape.  I removed one, only to discover that these are actually flat printed
strips -  http://imageshack.com/i/f0ya1BtZj . I wasn't expecting this, but it didn't seem to be a problem.

Then, I took the pedals themselves apart.  This is done by drifting out the pin at the rear of the individual pedals.  At this
point, I got a real surprise.  I had assumed the pedal operated a mechanical switch, taking them apart revealed they were
actually optical - http://imageshack.com/i/hluO405ij - oh dear, re-think time!!  After this initial surprise, I could see
there was actually an advantage to this - I could retain the USB facility, should I ever need it. For the moment, I de-
soldered the USB wiring, making a note of what colours went where - http://imageshack.com/i/f0vGwCVrj - at a later date, I
will re-connect this cable, much shortened, so it doesn't get in the way.  If needed, I can use a M/F USB extension cable to
connect to the tablet.

A quick rummage in the 'bits box' found a couple of microswitches (probably liberated from a defunct mouse).  These were
temporarily glued into position - http://imageshack.com/i/pcahqTooj - and wires connected to the NO contacts. A similar
conversion was made to a second pedal (I will do the third one when I find a practical use for it).  All the wiring was run
underneath the pedalset (using very thin wire) and re-taped.

The battery box was attached to the baseboard of the pedalset, using a couple of nuts and bolts, and another hole was drilled
to pass the new wires through - http://imageshack.com/i/p5SzcyXyjhttp://.../p5SzcyXyj - all that was required
was to solder the wires to the E-Key module - http://imageshack.com/i/p50yUglbj .

The finished job is here - http://imageshack.com/i/pd7IYEX5j - the battery box protrudes slightly over the baseplate because
the on/off switch is underneath.  I elected to mount it this way to make battery changing easier.

For the future, all that remains is to fix the microswitches permanently in place with a couple and nuts and bolts (I can't
rely on superglue as a permanent solution) and re-connect the original USB wiring, so that the pedals may be used either
wired or wireless. When I find a practical use for the third pedal, I'll add the necessary wiring.

Total cost has been around €45 - well below the price of a commercial unit.
Graeme

1: Samsung 12.2" SM-P900: Android 5.0.2 
2: eSTAR GRAND HD Quad-Core 4G 10.2": Android 5.1 
3: Home-built BT pedal

Some of my music here
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#2
A good detailed post Graeme, I was the one who suggested the Adafruit EZ-Key module but haven't got around to getting one myself. I used heavy duty foot switches (Maplin code N92AP) on my hacked Bluetooth mini-keyboard design as I had them to hand, but a flat pedal mechanism would've been the better option.

Can you confirm there are no timeout issues with the EZ-Key module?
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#3
As far as I can tell (and I haven't actually asked the question) the EZ-Key has no timeout, which is why I went for a switched battery box. If it has, then it's long enough not to be a concern.

Somewhere around here, I have a Roland FS-6 Dual Footswitch - http://www.bossus.com/products/fs-6/ . Being metal, this is a pretty substantial bit of kit, much stronger than the cheap plastic pedals I used. There has to be enough space inside for an EZ-Key module and the battery supply is already in there. When I find it, among all the other stuff I've acquired over the years, I'll knock up another BT pedal.
Graeme

1: Samsung 12.2" SM-P900: Android 5.0.2 
2: eSTAR GRAND HD Quad-Core 4G 10.2": Android 5.1 
3: Home-built BT pedal

Some of my music here
Reply
#4
Here's another option for a cheap Bluetooth pedal. Easy to make, no need to have any knowledge of electronics, and it works great  Smile 
I'm working in vocational training for disabled teenagers in Egypt. Besides other items we're making Cajons. So I made a Bluetooth pedal in the same style as the Cajons, see attached pictures. I kept the mouse as it was,  I only removed the scroll wheel. There's an opening in the bottom which enables me to switch the mouse on and to change the battery.
 
           
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#5
That's a creative bit of thinking, well done.

I found the problem with using a mouse was that stupid things kept timing out at the most inappropriate moments.

They're pretty big cajóns, mine is only about 2/3 that size Smile .
Graeme

1: Samsung 12.2" SM-P900: Android 5.0.2 
2: eSTAR GRAND HD Quad-Core 4G 10.2": Android 5.1 
3: Home-built BT pedal

Some of my music here
Reply
#6
Thanks Graeme.
The cajons are actually not that big: the height is 46cm or 18", the boys are quite short...
I haven't had any problems with this pedal yet. Until now it's working flawless.
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#7
(03-06-2015, 06:43 PM)Arie Wrote: The cajons are actually not that big: the height is 46cm or 18",  the boys are quite short...
I haven't had any problems with this pedal yet.  Until now it's working flawless.

They are short boys Smile .

Does your mouse time out at all?  If it doesn't, I'd be interested to know what model it is and if it will work with BT2.1?
Graeme

1: Samsung 12.2" SM-P900: Android 5.0.2 
2: eSTAR GRAND HD Quad-Core 4G 10.2": Android 5.1 
3: Home-built BT pedal

Some of my music here
Reply
#8
Thanks for your ideas GraemeJ. I also have the same 3 pedal unit you have. Just a note, - you can really make the pedal quieter by putting a thin strip of sticky-sided felt along the front and sides of each pedal where the moveable pedal contacts pedal the base. Much better. Tongue
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#9
(03-06-2015, 10:21 PM)GraemeJ Wrote:
(03-06-2015, 06:43 PM)Arie Wrote: The cajons are actually not that big: the height is 46cm or 18",  the boys are quite short...
I haven't had any problems with this pedal yet.  Until now it's working flawless.

They are short boys Smile .

Does your mouse time out at all?  If it doesn't, I'd be interested to know what model it is and if it will work with BT2.1?

It's a cheap Bluetooth mouse,  made in China,  not a known brand. Maybe it's so cheap because there's no time-out build in...   Big Grin
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#10
I tried several BT mice - both cheap and more expensive (all of which seemed to have been made in China) - and they all timed out! Seemed to be a standard thing. That's is why I was wondering which model you had used? A mouse that doesn't time out would be a considerably cheaper option than the EZ-Key module I used.
Graeme

1: Samsung 12.2" SM-P900: Android 5.0.2 
2: eSTAR GRAND HD Quad-Core 4G 10.2": Android 5.1 
3: Home-built BT pedal

Some of my music here
Reply


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