convert a old 8-pin midi foot controller, to...... - Page 1
Forum section: electronics / beginners

author: ziegler
author_rank: Regular Contributor
timestamp: April 15, 2015, 10:26:09 am
content: I have this "Technics foot controller SZ-FC2" laying around, but i cant use it, because of the old 8-pin midi cable.Just opened it up to look inside and it's the most simple thing I have seen.So the thing is, I want to convert it to something that I can use (5-pin midi or usb-controller), but as the noob I am, I'm unsure of how to do it.here some photos....- the cable has 8 colored wires in it.- each foot pedal has 2 wires.I have uploaded a drawing here, over the wires.thinking maybe I can use an arduino, in some way.

author: ziegler
author_rank: Regular Contributor
timestamp: April 15, 2015, 10:26:51 am
content: more photos

author: daybyter
author_rank: Frequent Contributor
timestamp: April 15, 2015, 10:56:36 am
content: Arduino Nano plus Midi out cable? Look for the dccDuino clones at eBay.

author: ziegler
author_rank: Regular Contributor
timestamp: April 15, 2015, 11:09:47 am
content: Do I really need a 8-pin-midi-female part?Can't I just solder the wires to each it's own pin on the nano ?

author: Ian.M
author_rank: Super Contributor
timestamp: April 15, 2015, 12:31:31 pm
content: If its got an 8 pin DIN connector and no electronics, battery or PSU, its *NOT* MIDI. You'd need to gut it and wire each pedal to an Arduino (or other MCU) input as a switch (but do check they are switches, not variable resistors) and program it to output MIDI commands of your choice depending on which switches were operated. It would need power, so its probably more convenient to leave the pedal and lead as-is and simply build a converter box that can live with all the other kit rather than adding to the snakes nest of wires on the floor.

author: ziegler
author_rank: Regular Contributor
timestamp: April 15, 2015, 02:17:18 pm
content: Quote from: Ian.M on April 15, 2015, 12:31:31 pmI checked, they are switches.Quote from: Ian.M on April 15, 2015, 12:31:31 pmThere is room in the wood cover (maybe I need to drill a little more room) for a small nano board inside of it, I could connect all the 8 wires from the pedals to the nano-board.here is an idea I'm not sure about, but- if I add a small usb-cable to the usb port (of the new internal nano board)- then cut off the head in the other end of the usb-cable, so I can connect the 4 wires from it, to the original 8-pin-midi-cable, leaving the 4 last wires unused.- and lastly, cut off the midi head, and convert it to a USB port.could this work ?

author: ziegler
author_rank: Regular Contributor
timestamp: April 15, 2015, 02:22:39 pm
content: I forgot to take photos of the switches.it looked like this.

author: ziegler
author_rank: Regular Contributor
timestamp: April 15, 2015, 03:00:17 pm
content: I will be looking in to this more thoroughly then I have (which is not at all).here is some links I will be reading:http://www.instructables.com/id/Arcade-Button-MIDI-Controller/?ALLSTEPShttp://www.instructables.com/id/USB-MIDI-Controller/?ALLSTEPShttp://www.instructables.com/id/USB-Midi-Device-from-old-Gamepad/?ALLSTEPSIf you guys have some learning resources, related to this project, I would love to hear them.

author: Sigmoid
author_rank: Frequent Contributor
timestamp: April 15, 2015, 03:34:19 pm
content: Quote from: ziegler on April 15, 2015, 02:17:18 pmWell, as it's been established, it's not a MIDI cable at all.Anyway... I don't understand why you'd want to do this. If you want to add the logic board inside the housing of the pedal, just use a regular USB cable, and save this 8-wire cable for some time you might need it.USB is pretty sensitive to cable quality, so you're best off using a factory made one.

author: dentaku
author_rank: Frequent Contributor
timestamp: April 15, 2015, 08:15:59 pm
content: Notes and Volts has good info and using MIDI with Arduino.https://www.youtube.com/channel/UC97oxpI-kInN6trsvs6yLNgSince you say those are just switches it won't make for a terribly interesting MIDI controller. All it will be able to send is 3 separate NOTE On / NOTE Off messages with a fixed velocity if you manage to modify it to send out MIDI. Of course if you have use for 3 foot switches it should be greatIt frees up your hands to do other things.This has made me wonder if I should try and send MIDI with my Arduino UNO connected to my Expression Pedal which of course is just a pot in a box connected to a lever.

author: ziegler
author_rank: Regular Contributor
timestamp: April 15, 2015, 11:33:12 pm
content: Quote from: Sigmoid on April 15, 2015, 03:34:19 pmthat sounds right and when I look at the price on a 2 meter cable, I think it's the best and safest way.Quote from: dentaku on April 15, 2015, 08:15:59 pmthese videos look cool and easy, this is something I will use in the future (and now).thank you for sharing this channel with me.Quote from: dentaku on April 15, 2015, 08:15:59 pmthere are 4 foot switches.I'm happy that this small project, (it will be my first hack/create project) can help inspire others to do same.All the equipment we don't use no more, could be separated for parts or hacked into something more usable.In my case I have this old one I got for free, wanted to use it with present day technology, and I know that this is cheaper than buying a new one (I also get some skills in the process).- I looked around for something similar to what I wanted, to see how cheap I could get a real midi-foot-controller (not just a button on a box), and this was what I found.http://www.thomann.de/gb/line6_fbv_express_usb.htmSo back to the topic, I have been looking to buy the board that I need, but I can't afford the real ones from arduino, so I will have to do with a cheap clone of them.What I need to know before I buy one is, will a smaller board, as the arduino nano, work for my project, or should I buy a bigger one, as the arduino mega.- the price for a clone of the nano, is around 12 to 15 dollars.- the price for a clone of the mega, is around 17 dollars.- the price for a clone of the uno R3, is around 12 - 13 dollars.All of these clone board, have prices that are pretty close to one and another.there is different versions of the nanoboard, like the one called "V3" and another called "pro", is one better than the other ?

author: dentaku
author_rank: Frequent Contributor
timestamp: April 16, 2015, 01:25:55 am
content: I'm just starting with microcontrollers so I'm not sure what would be the best but you can get Arduinos much cheaper on eBay.http://www.ebay.com/itm/USB-Nano-V3-0-ATmega328-16M-5V-Micro-controller-CH340G-board-Arduino-/311064700128?pt=LH_DefaultDomain_0&hash=item486ce6a4e0http://www.ebay.com/itm/NEW-UNO-R3-ATmega328P-CH340-Mini-USB-Board-Compatible-Arduino-/311155383820?pt=LH_DefaultDomain_0&hash=item48724e5e0cJust make sure it's an Arduino with a USB port on it because some tiny ones require a separate USB RS232 board to program them.

author: ziegler
author_rank: Regular Contributor
timestamp: April 16, 2015, 02:41:26 pm
content: I can't buy those from China, because it's outside of europa. When I buy products from outside europa to Denmark, the price get stupid high.So I buy them from England instead, I picked 1 nano and 1 mega.(these 2 boards, have a total price, that is a little lower than, the price of a real Uno R3 from my country)When I asked about which one is better, then I was thinking about ram, space and chip-speed, but it don't seem to be a problem for what I gonna use it for.I will get them in about 2 weeks time.

author: ziegler
author_rank: Regular Contributor
timestamp: May 06, 2015, 03:22:35 pm
content: sorry it took so long, I had a lot to deal with lately.I got both boards, about 2 weeks ago, haven't used them yet.

author: ziegler
author_rank: Regular Contributor
timestamp: May 06, 2015, 03:50:08 pm
content: I tried to click the switches, but I can't hear any "click" sounds from them.Every switch have 2 wires each, I think one of them should be connected to ground/power, I'm not sure though.then I will connect the next wire to one of the nano's Analog pins, so I can read what output it give.This is of cause all just talk from my side, since I don't know what I'm doing, so if any of you knows better, please talk me.

author: Hideki
author_rank: Frequent Contributor
timestamp: May 06, 2015, 06:59:36 pm
content: Connect one wire to ground, the other to an input. Turn on the built-in pullup resistor with pinMode(pinNumber,INPUT_PULLUP); then read the state of the pin with digitalRead(pinNumber).If the state is LOW then the switch is pressed (because it's connected to ground), if not pressed, the function will return HIGH.

author: ziegler
author_rank: Regular Contributor
timestamp: May 08, 2015, 06:29:22 pm
content: Quote from: Hideki on May 06, 2015, 06:59:36 pmthank you so much for this, you saved me from a lot of frustration.I tried all you said, with one foot-swith, and it worked just fine.then I thought if one work, then I can just connect everything together now. (nope)There is a metal part in the middle (look at some of the photos of the foot controller), that I think could work as ground, so I added all the switches' ground-wires to that.Now the nano says that, they are all on, at all time. (tried having all footswitches down, nothing happens)I think that, there is a shorting somewhere, somehow.Can anyone tell me (where it)/(what) went wrong?

author: Hideki
author_rank: Frequent Contributor
timestamp: May 09, 2015, 09:55:55 am
content: Quote from: ziegler on May 08, 2015, 06:29:22 pmNo... but if you have a multimeter you can at least figure out if they are indeed shorted or if you have a bug in the software.The footswitch wiring is weird. I'm sure it makes sense for the original equipment it was made for. It doesn't really matter now that you have rewired it yourself.

author: ziegler
author_rank: Regular Contributor
timestamp: May 09, 2015, 11:56:15 am
content: I used my meter's continuity-mode to test the switch, it gave a sound, before and now. So the connencesing is open.when the switch is pushed down, the connecting closes.the DC-Volts from the nano is around 2,8 and 3,8.When the switch gets pushed, it goes down about 0,2 Volts.

author: ziegler
author_rank: Regular Contributor
timestamp: May 09, 2015, 12:17:44 pm
content: Here is some photos of how it look so fair.All the black wires are power, from the digital pins on the nano. (pin: 2, 3, 4, 5)

author: Hideki
author_rank: Frequent Contributor
timestamp: May 10, 2015, 11:20:19 am
content: So where is your common ground point connected to the microcontroller? I can only see four wires going there.If you don't know why this also needs to be connected, take a break and make sure you really understand the reason why.

author: ziegler
author_rank: Regular Contributor
timestamp: May 11, 2015, 06:49:54 pm
content: I got it to work now, by adding a wire from the ground-pin, to the metal part on the controller.You are right Hideki, I don't really know any of the basis of all this, which is something I will read up on, when I have more time than I have now.Now the next part of this project, involves a lot of programming, which is something I'm pretty good at (just not with microcontrollers).I will update this page when I have more to share, right now I'm only thinking about a basic MIDI controller, but I have some ideas for addons, which can be added to it later.