Convert old 25 note pedalboard to MIDI?

[NTL2009]

I'm looking into a dual manual clone-wheel organ (Hammond vintage, Crumar, Viscount?), and see that pedalboards are > $1500 US.

I have an old Yamaha Electone E3 that will likely be scrapped It has a nice 25 note pedalboard, so I'm looking into wiring this for MIDI to connect to whatever dual manual organ I get. I've searched these threads, and key contact to MIDI encoders are not as available/cheap as I would have thought. They mostly seemed to be from small companies, mostly extinct. Or Arduino DIY, and I'm not sure I want to dig into the code and everything.

I'm starting to think the simplest, cheapest, and easy to replace if it goes bad, would be to just strip a small MIDI keyboard/controller down and wire the pedal switch to the key switches. There are a few mini 32 note MIDI keyboards available for < $50, or maybe I can find a MIDI keyboard at Goodwill or something? Any thoughts?

Also, some of these controllers only have USB-MIDI, which is expecting to see a host, not a 'slave' device. Will the organs I'm considering accept USB-MIDI note events, or is that only through the 5-pin MIDI IN connectors?

[John Kinkennon]

The standard 5-pin MIDI connection is the safe choice when in doubt. USB-MIDI is the low latency, high traffic choice, but none of that matters with a few notes from a pedal encoder. Any company manufacturing encoders will be small as it's such a niche market. My favorite is a Bulgarian outfit, MIDI Boutique. Their encoders are affordable and they even provide reed switch cables if the Electone contacts are difficult to use. I seem to recall some of the Electone pedals being in a 2x12 matrix though I am not entirely certain.

The Arduino DIY method is very affordable of course and not much work though that's easy for me to say since I program quite a lot. The Teensy boards are really easy to use if going the Arduino route.

EDIT: Of course the easy Teensy application is USB-MIDI which may not work for your application.

[NTL2009]

Thanks (I would have replied sooner, I didn't have my notifications set right).

Somehow I missed the lower priced MIDI Boutique offerings that seem to be just what I need. And their web site looks professional, I suspect they will be around for a long time - many of the others I looked at had been abandoned.

So there is the 64 (8x8) encoder with 5 Pin DIN MIDI out: http://midiboutique.com/MIDI-Encoders/mkc64x?limit=100

It's 55 € and just 10 € shipping to NA. so about $81 USD with shipping (and I just applied for a 10 Euro coupon). For that price, I won't bother with DIY (unless I do it as learning experience), and as you say, that's USB MIDI which I'm guessing does no good for driving an instrument (needs a USB host/computer).

There's also the velocity sensitive version, just a bit higher priced. Don't need that for the pedal board, but it also accepts 4 pots to map to CC, and it might be fun to mount some pads on the pedal board for velocity sensitive effects? But I don't know if you can wire this to a pedalboard with single switches? Oh well, probably simpler to buy a small pad device and add a MIDI hub?

http://midiboutique.com/MIDI-Encoder...dle1?limit=100

BTW, for the Yamaha Electone E3 (~ 1975 vintage) that I have - the pedalboard itself has no switches, just tabs that stick out. The switches are mounted in the base of the organ. So I'll probably add reed switches/magnets, or look for hall effect sensors (not sure they can be used in a switch matrix? More research!).

FYI: There's another thread on converting MIDI USB to drive an instrument - I'm thinking that MIDI Boutique might want to take that project on, should be right up their alley, and there seems to be demand for it, with so many products now dropping the DIN for USB only. I'll look up that thread later...

[John Kinkennon]

The first board would be a good choice as you can add the diodes as shown on the user manual wiring diagram. I have an encoder similar to the second board except with USB-MIDI out. I use it for a 4th keyboard that plays virtual piano and bells. The second board would be tricky as it really must see two contact closures to work correctly.

Reed switches work very well but take a bit of experimenting to get them at the best distance from the magnets. I don't have experience using mechanical switches -- use some sort of mechanical linkage that provides a bit of "flex". Or perhaps the Electone switches can re salvaged from the console and reused.

[DaveSchmauch]

Hey John, if I replace a few reed switches in a 70's Allen pedalboard, do you have a recommended substitute? The glass is almost exactly 1" long. And are they normally closed or open? My understanding is that the magnet closes the normally open reed (circuit). Thanks!

[John Kinkennon]

I'm afraid I don't have a part number at hand but hopefully someone else will. I've broken one or two but always found a replacement from an old pedalboard.

[NTL2009]

The standard 5-pin MIDI connection is the safe choice when in doubt. USB-MIDI is the low latency, high traffic choice, but none of that matters with a few notes from a pedal encoder. Any company manufacturing encoders will be small as it's such a niche market. My favorite is a Bulgarian outfit, MIDI Boutique. ...

The Arduino DIY method is very affordable of course and not much work though that's easy for me to say since I program quite a lot. The Teensy boards are really easy to use if going the Arduino route.

EDIT: Of course the easy Teensy application is USB-MIDI which may not work for your application.

UPDATE: You mentioned the Teensy boards, and I got curious. I'm not really much of a programmer (I did measurement instrument control and some other programming as part of my job, but nothing 'sophisticated'), but I have done a few things recently using the ESP8266 that I flashed with MicroPython. I found Python easy to use and it isn't unique to these controllers (Python comes installed on my Linux distros).

I found that the Arduino IDE has a very nice, easy to use MIDI library available. Then I saw that they also have a library for the ESP8266. Since I have a few ESP8266 boards laying around, I tried a simple Note ON/OFF loop, and it compiled/flashed and the UART blinked the LED OK, so I added a transistor buffer to the UART out port and connected it to a 5-pin DIN connector to a MIDI keyboard, and that worked too. Easy!

So while the MidiBoutique board would do the job for me at ~ $80, I'm planning to program an ESP 8266 for this, as I think what I learn might be applicable to some other projects I'm considering (convert drawbar and misc switch/pot inputs to MIDI CCs). The ESP8266 is very powerful, and incredibly cheap ( less than $8, and includes WIFI, which I don't need for this app - but then I might use these for something else if this falls through). So I won't be dependent on suppliers for my specific needs, and if I need a half dozen of these, will actually be pretty cost effective.

There are cheap 16:1 mux boards available, so I'm thinking just use 2 of these, and I can read all 25 pedal notes as simple OPEN/GROUND contacts - no matrix/diodes required. Here are some links:

"HiLetgo 2pcs ESP8266 NodeMCU LUA CP2102 ESP-12E Internet WIFI Development Board Open source Serial Wireless Module Works Great with Arduino IDE/Micropython" 2 for ~ $15
https://www.amazon.com/HiLetgo-Inter...010N1SPRK?th=1

16:1 MUX $5.29 on Amazon, but less than $1 each for 10 on ebay/aliexpress (slow boat from China).
https://www.amazon.com/HiLetgo-CD74H.../dp/B01DLHKLNE

https://www.aliexpress.com/item/10PC...723841185.html

Setting up the Aurduino IDE for ESP8266:
http://arduino-esp8266.readthedocs.i...nstalling.html
MIDI Library here (UART wired to 5-PIN DIN):
https://github.com/FortySevenEffects...o_midi_library

Nice explanation and sample code of MIDI Library on Teensy
(this code sample worked on my ESP8266 w/o any mods):
https://www.pjrc.com/teensy/td_libs_MIDI.html


I was really surprised how easy this was. Installing the Arduino IDE, adding the libraries,
flashing and running the code all pretty much worked the first time for me,
and I'm just not that experienced.

Only problem I had was spaces in the path name where I tried to install, figured that out pretty quick.
Anyhow, I'll update this when I actually get the reed switches wired and have something working (or not).

[John Kinkennon]

I'm excited to read about the good results with the Teensy, oops, with the ESP8266. We are fortunate to live in an era where great results can be obtained from extremely affordable hardware. I've got a Teensy 3.6 that I've experimented with. I haven't yet used one in an organ console, but I know I will sooner or later when I have one more set of pistons (or whatever) than my encoder can handle.

[Tim_at_Jonas]

Do some searches and see if you can find out how Dennerlein does it.

[NTL2009]

... I'm planning to program an ESP 8266 for this, as I think what I learn might be applicable to some other projects I'm considering (convert drawbar and misc switch/pot inputs to MIDI CCs). The ESP8266 is very powerful, and incredibly cheap ( less than $8, and includes WIFI, which I don't need for this app - but then I might use these for something else if this falls through). So I won't be dependent on suppliers for my specific needs, and if I need a half dozen of these, will actually be pretty cost effective.

There are cheap 16:1 mux boards available, so I'm thinking just use 2 of these, and I can read all 25 pedal notes as simple OPEN/GROUND contacts - no matrix/diodes required. ....

Anyhow, I'll update this when I actually get the reed switches wired and have something working (or not).

I received my Crumar Mojo61 last week, and had my pedal board working and ready to set up (along with my old DX-7 to act as the lower manual keyboard controller for the Mojo61). So time for the promised update:

Everything worked out well. As I mentioned, I'm not a 'sophisticated' programmer, but this really was pretty simple code, and easy to follow examples from the web. I soldered the tips of the header pins on the ESP8266 onto a PCB proto board, and cut a strip between some of the lands to hold a 40 pin connector so I could plug in a ribbon cable which is wired to the reed switches. Those 16:1 mutiplexers worked well. It is somewhat tedious wiring to 25 reed switches, and wiring in pull-down resistors to each MUX input, and wiring the control lines. It's all simple on paper, but ends up taking some time to assure each connection is done just right.

Trickiest part was probably getting the reed switches set just right. I found some data sheets, and reed switches have a sort of null point in the middle, so you need to set the placement just right to get the switch to close as you push the pedal, but not hit the null and open again as the pedal bottoms out and the magnet gets closer to center.

OK, at times I wondered if this was worth it versus buying an encoder from one of the suppliers. For a one time deal, I'd say just buy one. But I'm glad I did this, as it really was pretty easy (just tedious - but much of that was the reed switch set-up, which you'd have to do anyway), and as I mentioned, this gives me the courage to tackle a few other things I'd like to try (external drawbar controller for the Mojo61). Plus, I have 32 inputs, and only 25 pedal notes, so I can adapt the software for functions I may want to try in the future. I couldn't do that with a purchased unit. As an example, I have a 'programming switch' for input #31, which sends an "All Notes Off", and if held, allows me to use various pedals to change default settings, like MIDI CH#, and Octave Shift. I might set up a Mono/Poly mode, but I'm not sure I really need it for a CloneWheel set up.

So that's that. If anyone is interested, I could post the code and some wiring diagrams somewhere. That would give me some incentive to make a clean-up pass on the code (some old cruft from debug and different experiments that should be cleaned out).

Oh, I did monitor the scan rate, I get ~ 380 scans per second of the 25 pedals. Using a scope, the MIDI transmit of NOTE ON would occur within the expected ~ 2.6 mSec max scan time, and half that on average, which is plenty fast for pedals. Note that I used the Analog-to-Digital converter to read the switches - a digital input would be much faster, but I figured I didn;t need it to be any faster, and this makes it easy if I want to put a pot on any of the other inputs.

BTW, one of my "out there" thoughts for the external drawbar controller is to provide a 'meld' function pot. It would provide a smooth pan between the settings of the "A" drawbars and the "B" drawbars. So with the pot full left, you get the "A" setting sent to the Mojo, full right you get the "B" settings. As you move the pot towards center, the setting would be a weighted average of the two. So you could make complex drawbar changes with a twist of the wrist. An example:

A: 888080001
B: 888048888

"Meld" pot @ center would give:

888064444 or more accurately 88806444(4.5)

I'm pretty sure the Mojo takes 0-127 for levels, so 4.5 would be sent as ~64, 4 as 56, etc.

And moving the pot left-right from center would smoothly adjust each of these values to that in-between level. So it's easy to set it up to have some drawbars moving in while others move out, and at different rates, which can be difficult/impossible to do live. I think I can even add a 'sensitivity' to each, so that some would go full range with a slight tweak of the knob, other would need a full turn to go from A to B or B-A.

[peterb_2795]

Hi NTL,

I have read this post with much interest as I am in a kind of similar situation in that I have a 25 note pedalboard (off a C3) that I want to wire as both a midi controller *and* a midi synth audio output device, the intent being that the pedal board can act as either a midi controller connected as an input in some cases and in other situations, as a stand-alone audio source.

I had concluded (as you did earlier) that one of the midi kits offered by http://midiboutique.com would be the way to go. They provide two pedal kits (complete including wiring) for EU165.00 (reed switches) or EU190 (hall effect). If I were to add up all of the separate parts and postage costs to acquire similar, I would not be saving much in dollars but having a better learning experience. I would be interested to see a few piccies of what you have eventually ended up with from both a wiring and an integration perspective.

I have of course done the usual web searches and see that there are a number of excellent projects out there that all seek to provision a midi encoder using Arduino, Teensy or SBC's. There is a well documented project at https://hackaday.io/project/4741-org...idi-conversion but even then, the author later says that he moved to a Teensy board.

I would be keen to hear how much time was invested in wiring the reed switches and as to how you arranged them for your case. For the cost of the kit from midi boutique, I might be better off taking that as a convenience route for the encoding and investing more of my time into the midi output side. My initial thoughts for obtaining a stand alone environment are to take the midi controller signals into a Raspberry Pi board that is running FluidSynth (Linux/Raspian) to produce my pedal tones and (say) string bass analog output. The Pi comes with an audio out chip onboard plus, if this is found to not be up to scratch, there is the HDMI output that could be put into a splitter for improved audio quality.

I think it would be pretty neat to have a 25 note pedalboard that I can use under a re-cased (and modded) M100 or a (to be) Oakland style rebuild (ex C3). Note: original cabinets have (and will be) gifted into our small Hammond community (here in Oz) for re-use.

At this point, I am assuming that the audio out would simply feed into the input RCA located at the expression pedal housing and I would be on my way (I'm sure there will be gotchas like synth library, waveform and actually getting something that has the deep tones/frequencies of the pedals with all of their "fartiness").

Either way, thank you for sharing your midi pedal board adventure, you have certainly provided me with some food for thought and a desire to put a midi pedal board onto my "ToDo" list ...

regards,
Peter

[NTL2009]

Thanks for your interest. I'll give a quick reply now, as I've got a few things taking my time today, and will try to get more details to you later. At this point, since I have a few other projects in the works, I guess I should look for a blog or website to publish this stuff, describing on a forum will get a little awkward I think. I'm not sure what is best for that, a google site, hackaday, instructable, other? Any suggestions?

I think for a one-and-done deal, the midiboutique products look pretty good. But like you, I was also interested in the learning experience, and now I'm really glad I did, as it was pretty simple, and the knowledge I gained gave me the confidence to take on some other projects (I'll describe a bit below, and start a new thread on those).

As an example, I now plan to add a MIDI-MERGE function to this pedalboard encoder, to free up a MIDI input on my recently purchased Crumar Mojo61. I'll run my lower keyboard (a DX-7 used as a controller only for now) into the merge, so pedals and lower keyboard use only one of the two MIDI-IN on my Mojo61. That keeps the other MIDI IN open for my other project.

Overall it was pretty easy. Wiring the reed switches was not a lot of effort (I used a ribbon cable with connector on one end, so I could unplug the board from it), but the mounting was more work. I ended up with a separate little 1/4" thick board with a slot and screw so I could adjust each one, and the ends of the pedals are not the same length due to the radial layout, so I had spacers on some, and it was all a bit more 'tweaky' than I would have liked. But the Hammond pedalboard might be a bit easier to use? The Yamaha pedals have a metal tab at the end to press the switch in the console, I found just sticking the magnet on that piece would trigger the switch - but maybe it also made the magnetic field wider and I may have been better off removing those and sticking the magnet onto a non-magnetic material? But in the end, it has been working well.

The ESP 8266 is cheaper than the Arduino boards ( ~ $5), has good support with the Arduino IDE, and is fast (80Mhz processor). In the testing I did yesterday, I could loop on a MIDI in about 105,000 x per second, and when I tried my hardest to overflow the input with continuous control data, which runs from 0 through to 127 (pumping the swell pedal which throws out a LOT of data, and simultaneously pulling 9 drawbars in and out as fast as I could), I never, ever got any bad data, and it was still managing about 90,000 loops per second under full load. So I don't think that will affect the timing of reading my pedal switches ( I will put the MIDI.read() in between each switch check and not wait for a full switch scan, as I might lose some MIDI data during that ~ 2.5 mSec full scan). Math says that should only add ~ 0.25 mSec to my current ~ 2.5 mSec scan time.

I'm using 16:1 MUXes rather than the shift registers in that hackaday link, not sure of the pros/cons for switches (lower GPIO pin count maybe- shift registers use SPI I think?), but since I also plan on reading pots, I need the analog switch capability of those MUXes.

I have a few lines of code to catch bad data, which I got plenty of when I put print statements in the loop (which slows the response), so I feel confident it is working as expected.

Note that I have not done anything with audio on these projects, these are strictly MIDI data in/out, driving keyboards to produce the sounds.

The ESP8266 also has wifi, which I have not used in for this project (I did for another non-music project), but has potential. It also has a basic file system, which I'm, using to store presets on the my drawbar expander project.


My drawbar expander project has some unique functions (described a bit in an above post). That is coming along well, and I'm about ready to order the hardware (I've kind of mocked it up to test the code, w/o a full hardware set-up). I'll start a new thread on that when I get a little further.