737 overhead panel interface problem

Hi everyone.
first of all, i looked through all the pages and topics, and couldnt find the answer to my problem. i apologize if this topic has been dealt with.

so i finally started building my 737 cockpit, starting with the overhead panel. since i cant get my hands on any I/O cards like the BU036X, i had to resort of joystick hacking.

After taking a cheap joystick apart, i realized how hard it was to solder those minute connections on the board. took me 2 days to get about 10 switches on that thing. after each successful solder, i checked the connection with a multimeter before sealing the solder with silicon using a silicon gun. upon connecting the controller to the pc, i had no problem. tested the joystick with connecting toggle switches, and it worked fine. so i pulled out the cable, and started connecting the rest of the switches, with ever-growing excitement. when i was done, i plugged in the joystick, and to my disappointment, it said, USB device unrecognized. no idea what happened. my best is that the heat from the iron destroyed the IC or micro controller. or maybe it was the hot silicon. in either case, i looked into online solutions and found USB keyboard hacking. did more research, and it sounded like a good idea. something that might work, I had two options. to go with an old keyboard, which does not have matrix, but individual keys. the other option was, more easily available, modern USB keyboard. so i decided to go with the latter.

I quickly opened up the keyboard, to discover two transparent sheets of plastic, with copper wire running through them. as per hacking guide, i took upon the painful and arduous journey to resolve the matrix.

A few days later, after i had all the key combinations, i connected two toggle switches to the PCB with the keys "A" and "B" respectively. opened up FSX, loaded PMDG 737, went to FSUIPC, keys, created a MACRO for the Taxi Lights and Logo Lights. programmed FSUIPC for no repeats and there i had it. both switches turning on and off together and independently as intended. excited, i starting the physical construction for the overhead panel. took me a few weeks to wire everything, finding and putting in switches, even mounting the overhead panel. wiring the darn thing turned out to be more complex then what i had initially anticipated. thankfully, i kept it organized from the beginning.

Next came the programming of every single switch. creating MACROS all the way. upon testing the switches one by one, they all seemed to work as intended. but thats when i hit a rock. when i turn on 3 switches on the same circuit, the switches wont turn on. scratching my head, i opened MS word, and tried the same combination of switches with a keyboard and realized that the keys "KCD" cannot be pressed together. apparently i need a better keyboard for that. some "N" type keyboard. even that doesnt allow more than 12 keys to be pressed down at once. ive been researching this for a few days now. and have come up with a blank. here are a few solutions that i can think of:

1. using relays and capacitors for momentary key presses. (im no engineer. so no idea how to read schematics or go about it)

2. maybe use an older keyboard? the ones that did not have matrix. i dont know how many key presses they allow.

3. go back to using a joystick/controller and be careful with the soldering.

4. maybe FSUIPC has a solution? the advance user guide is french to me.

5. off the shelf I/O cards. something that is not delivered in my country. so kinda pointless. but still id wanna know whats best. anything besides the 32 switch BU0836X?

6 maybe a keyboard emulator software that allows momentary key presses?

Any help would be appreciated. ive spent a zillion hours on this thing. i dont want to give up. Especially when i'm so close.

Well, if you need a cheaper IO Board, perhaps you should look into one of these:
GP-Wiz40-Eco USB Controls Interface [GPWIZ40ECOP] : GroovyGameGear.com, Always the best in Arcade, Jukebox, Kiosk, Gaming and Industrial controls

The only problem is that you live in the middle east, so the shipping charge might be high.

You might want to try using diodes on your on-off switches so they wont influence each other.
Have a look at Ian's site how to

Thanks. the board looks great. im always visiting the US. so might not have to get it delivered. its just what i was looking for. but it'l have to wait unfortunately

Diodes? really? have no idea how that would work. il have to look into it.

so the thing is, i've managed to create a momentary switch, using a capacitor and a relay switch. the toggle swtich now works exactly as planned. but the next problem, will i have to buy 50 relays for each individual switch?
any ideas appreciated.

so far.. this is what it looks like. really crude, i know. its drawn to scale. 1:1 of the actual overhead panel. the next one that i build will be with plexiglass.

The problem is probably due to the fact that you're connecting switches to a matrix. Now with momentary switches there's no problem but with on-off switches you get feedback to the other switches. This you can solve by putting diodes (dead cheap !) before the switch which only allow current to pass in one direction. No need for relays.

That's exactly the problem. Wow. Thanks. I thought I have have to spend a fortune getting on hands on so many relays. Il definitely start looking into, how to use diodes.
You wouldn't happen to have any schematics lying around right?


Found. Useful link. It actually might work
How a Key Matrix Work

That's it exactly. Now grab yourself a few hundred of the IN4001 on ebay and you're all set. Watch the polarity though of the diodes : the little stripe in the diode symbol is the white stripe on the diode itself.

Hi.

On a total different note, I am also building my own overhead. So I have drawn all overhead-panels in an illustrator-file, ready to print.
So if you like you can print the file (or parts of it). I printed it on white sticker and so I wrapped each panel around a piece of plexiglas/Foamalux.
Is a cheap way of making your own owerhead that looks - somewhat - like the real thing.
If you want to give it a go you can see how I have done on my blog (See the signature)

EDIT: So I can't upload the Illustrator .ai-file to the site. But an older pdf-version is on the blog.

Quote:

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Originally Posted by tiburon

That's it exactly. Now grab yourself a few hundred of the IN4001 on ebay and you're all set. Watch the polarity though of the diodes : the little stripe in the diode symbol is the white stripe on the diode itself.

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The diodes didn't work. I watched out for polarity. It worked partly. I used 3 diodes on the keys kcd as they cannot pre pressed together. Surprising it worked. But after switching it off and on about 5 to 6 times it stopped working. I spent hours trying to figure it out. But I couldn't. Even made the whole matrix on a piece of paper and and schematic diagram. So I've gone back to working with relays.
So I ordered about 20 6v relays. 5pin. Along with 1000um capacitors. Ran into anther problem. I understand that capacitors have polarity too. So I connected the circuit. Positive 6v external supply connected to the shorter leg of the capacitor and the electromagnetic switch connected to the keyboard. The switch works fine. The Problem is, it stays on. Doesn't close. Sometimes it does, sometimes it doesn't. And to top it off, one switch is working perfectly. I have the Same connection for the second and third switch, but they stay on. If I decrease the voltage, the switch doesn't flip at all.
Im guessing I'm using a wrong capacitor or something. Can someone help me with this? My frustration has peaked.

Quote:

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Originally Posted by BuildABoeing

Hi.

On a total different note, I am also building my own overhead. So I have drawn all overhead-panels in an illustrator-file, ready to print.
So if you like you can print the file (or parts of it). I printed it on white sticker and so I wrapped each panel around a piece of plexiglas/Foamalux.
Is a cheap way of making your own owerhead that looks - somewhat - like the real thing.
If you want to give it a go you can see how I have done on my blog (See the signature)

EDIT: So I can't upload the Illustrator .ai-file to the site. But an older pdf-version is on the blog.

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that is a brilliant idea. I read it somewhere else too but the author said he printed two stickers. One normal and one inverted on a sticky paper. So I dropped the idea because I didn't understand why he needed an inverted one. I eventually do want to install panel lights. So wont the whole sticker become translucent? How can I light up specific area of the overhead panel? For example the white lines connecting the cross feed and fuel pumps?
How easy is it to drill holes in plexiglass? Doesn't it crack or something?

checked your blog. Looks absolutely stunning. Hard to believe its a printout. Il be following it more closely. What IO cards are you using? Are the guages functional? You need a servo for that right?

for anyone reading this, and having similar problems, the capacitors and relays worked. i ran into quite a few problems, but eventually everything pulled together. i now have working momentary toggle switches for the overhead panel connected to a a keyboard PCB. il try to upload the schematics if anyones interested.