Converting real aircraft control panels

[nrgized]

Lately I've been scooping up panels for the UH-1 center consoles, ceiling and floor. Collecting is a patience game that requires little effort other then scouring all over the internet trying to find sources for parts.

 

I've not focused much on what to do when I have everything. Should be easy/possible right? :music_whistling:

 

The answer I'd imagine is more complex then a simple yes/no. The different scenarios I've thought of thus far include.

 

• Use the panels as reference to build your own (don't want to).
  
• Convert the panels to work with boards (very much prefer)
  
• Convert the panels to work with boards but might have to replace internals/buttons. (still better than first option)
  

 

Required material I imagine...

• Manuals for panels
  
• Oscilloscope
  
• Fill in the blank ____
  

 

I'm a programmer so the software part of the project is not a factor. But I have zero electrical knowledge. So I'm looking for help on where to start learning so that at then end of the day I can inspect the panels and know how to get them talking to a board. Or if not possible be able to ascertain if the boards are convertible.

 

My current almost assured to be fantasy and not even close to reality thinking is you hook up an oscilloscope to a panel, give it some power, and then move some buttons seeing what happens from each pin. Then write some board code and easy peasy japanesey.:joystick:

 

Any guides, links, helpful info would be appreciated.

 

Thanks!

[Boltz]

Best place to start is to search up part numbers for each panel and collect the related milspec and documentation for each. For the vast majority of the panels these will contain the pin out which states what function is related to what pin on the rear connector. That is far easier than trying to figure it out yourself with an oscilloscope or other equipment. For the panels you have you shouldn't need an oscilloscope to get them working. That's really only needed for instruments and other odd components used in the real thing. Your panels all look like straightforward digital switches. Even the mechanical frequency selectors are likely large multi deck rotary switches. That is what I've found in real radio panels.

 

Second thing you need to do is decide whether to use the original connectors on the back or not. If you use them then the panels shouldn't need opened up and it is a case of working up wiring based on pin outs in the milspec. But they are very expensive to buy new and often used as well. If you change to a different connector then they would be cheaper but each panel would need opened and rewired to your new connectors.

 

Cheers

Boltz

[nrgized]

Best place to start is to search up part numbers for each panel and collect the related milspec and documentation for each. For the vast majority of the panels these will contain the pin out which states what function is related to what pin on the rear connector. That is far easier than trying to figure it out yourself with an oscilloscope or other equipment. For the panels you have you shouldn't need an oscilloscope to get them working. That's really only needed for instruments and other odd components used in the real thing. Your panels all look like straightforward digital switches. Even the mechanical frequency selectors are likely large multi deck rotary switches. That is what I've found in real radio panels.

 

Second thing you need to do is decide whether to use the original connectors on the back or not. If you use them then the panels shouldn't need opened up and it is a case of working up wiring based on pin outs in the milspec. But they are very expensive to buy new and often used as well. If you change to a different connector then they would be cheaper but each panel would need opened and rewired to your new connectors.

 

Cheers

Boltz

 

Thanks Boltz!

 

I did notice that the wiring connectors, the round connecting plug bit not the wires, are a pretty penny. $75 was last I remember seeing although I did find some cheaper ones.

 

Knowing original connectors aren't cheap I was still planing on on using them instead of rewiring the connectors. The extra price payed for the connectors would help offset having to learn how and perform the rewiring of the panels. And while providing no real benefit for the sim it would keep the panels in there original state. A thought I like for whatever reason.

 

As for connecting the wires in broad terms what is involved with that? I don't imagine the arduino board has connectors for a AN/ARC 131 :smilewink:

 

I've seen threads here where people have various buttons etc connected to small little boards it looks like they built which then connect to the button box boards you hook up via usb. Is that the sort of thing that needs to be worked out?

 

Thanks for the help again. Trying to get my compass pointed in a direction to start learning what I need to.

[FSFIan]

EDIT: The following assumes you are going to use Arduino boards (see http://arduino.cc). They are the most cost-effective way to do this.

 

My recommendation would be to just start experimenting with electronics. Once you understand a few basic concepts, you know enough to interface with a lot of different types of devices.

 

Here's a minimum equipment list to get started:

• Solderless breadboard
  
• Jumper wires
  
• Multimeter (I can recommend the UT136B)
  
• An Arduino board
  

 

You will need things to connect to your Arduino board so you can play around with it. A few suggestions:

• A few LEDs (you'll need a 250 ohm resistor for each LED to limit the current to 20 mA)
  
• Assorted switches, potentiometers, and rotary encoders (you can use the ones on your panels if you can figure out which pins they connect to)
  
• A 16x2 character display
  
• A small 128x64 pixel graphic display
  
• A module with 7-segment displays connected to a MAX7219 driver chip
  

 

For recommendations on what tools to choose, watch the EEVblog episodes

and

. The first one focuses on quality, the second one on price.

You don't need everything mentioned in those videos, but it's a good list of things to consider buying and what to watch out for when you do.

 

Absolutely get one of these ultra-cheap Logic Analyzers and a set of test clips. Those analyzers copy the hardware design of the original Saleae Logic. They work with the open source sigrok software. A logic analyzer allows you to record several digital signals at once and display them on a computer. It can be an extremely useful debugging tool. For example, you can toggle certain I/O pins at specific places in your program and record that with the logic analyzer (you can't use the serial port if you are already using it to talk to DCS, and can't set breakpoints because there are no reasonably-priced debug interfaces for AVR chips). It is also a great tool to troubleshoot timing issues.

 

To interface panels to DCS, you don't need an oscilloscope. I spent $400 on a Rigol DS1054Z a while ago and I am very happy with it, but most of the things I use it for can also be accomplished with a logic analyzer and a multimeter (which is exactly what I did before I had the scope). Until you get into more advanced analog circuits, the oscilloscope is optional.

 

So what concepts should you learn?

My computer science curriculum included a class on the basics of digital electronic circuits. We were shown one particular diagram that helped me a lot. Look at page 10 (slide 19) of this PDF (not my university, but the diagram is the one I was looking for).

The diagram shows the different 'logic states' that a wire can have and what happens when you connect any two of them.

• 
  1 is a "strong logic high": a direct connection to the supply voltage (5V in case of most Arduino boards). It counts as a logic one.
  0 is a "strong logic low": a direct connection to ground. It counts as a logic zero.
  X is a short circuit. Avoid unless you like magic smoke.
  H is a "weak logic high": some point in the circuit that is connected to the supply voltage through a resistor (called a "pull-up resistor"). It counts as a logic one.
  L is a "weak logic low": some point in the circuit that is connected to ground through a resistor (a "pull-down resistor"). It counts as a logic zero.
  W is what happens when you connect L and H. The voltage will be somewhere between supply and ground, depending on the exact values of the resistors. For our purposes, it's an undefined state and should be avoided.
  Z is "high impedance": a wire that is not connected to anything (or is connected to supply voltage or ground through a very high resistance). Like "W", the logic level is undefined.
  

Using these six states, you can reason about digital circuits without ever caring about the precise quantity of any voltage or resistance.

 

For example, let's hook up a switch and explain how it works with these logic states.

---+-------- +5V
  | (1)
  |
 +-+
 | |  pull-up
 | |  resistor
 +-+
  |
  | (2)
  +-------- I/O pin
  |
  |
  /
 /    switch
/
  |
  | (3)
---+-------- GND

 

Node (1) is easy, it's directly connected to +5V so it's 1. Node (3) is 0. When the switch is open as shown, node (2) is H and the I/O pin will read as a logic one. If you close the switch, you connect H to 0. We can consult the diagram to find the new state that we get:

   X
0     1
  W
L     H
  Z

Look at 'H' and '0', and notice that '0' is higher in the diagram. So the new value we get is 0 and the I/O pin will read as a logic zero.

 

You can reverse this and use a pull down resistor instead, and some Arduino tutorials do that. Using a pull up resistor makes more sense on an Arduino, because the microcontroller has a built-in pull up resistor on each pin that you can enable in software ("pinMode(pin_number, INPUT_PULLUP);" in an Arduino sketch).

 

 

Which Arduino board should you buy?

I like the Arduino Nano because it's small and can be plugged into a breadboard. The Arduino Uno is the same thing in a bigger form factor that allows you to plug in "Arduino shield" modules, but you won't use those anyway because there is no "AN/ARC 131 shield".

The Arduino Mega 2560 is also worth a look if you want more I/O pins.

 

If you can live with a few weeks of delivery time, buy the Chinese clones from eBay.com or AliExpress.

 

Finally, have a look at my DCS-BIOS project (link in my sig). It is still in a proof-of-concept stage (only comes with support for A-10C, Huey, Mig 21 and Ka50, no GUI, etc.) but it works. If you have programmed before, you will probably quickly pick it up.

 

If you have any more questions, let me know. If you want to chat on Skype or TeamSpeak, send me a PM, I love helping people get started with this hobby.

Edited May 2, 2017 by [FSF]Ian

[nrgized]

 

Awesome, thanks!

[Duckling]

Hi nrgized. the more basic panels w stiches, rotatries, buttons etc are normally rather easy to interface when talking about connect or convert to 5V usage, ie how prepare them before the next step connecting,em to a chousen interface board as arduino and dcs-bios for example

 

I suggest open them up (gently) and check the internal wiring and create a simple connection diagram of the parts inside (like Ians sketch above) and backtrack the wiring to the connector pins. Verify them also with an multimeter (ohm meter). There quads/panels with (lets say) complex electronics that for pit building is beyond interfacing with normally means where the controlls (switchws, buttons etc) is easier to use if circumvent the rest of electronic interior and go for the switches etc directly.

 

Keep in mind, most quads has several redundency connections (a lot more wires then needed for a simpit is in there). Lamps/lndicator/panel backlight etc power requirements are typically out of scoop without additional electronics to handle these but,,, most of those can be converted by basic means to swap a oldie lamp to a LED if the circuit diagram shows where to connect etc

 

If you check inside the quad for a componenst partnumber labled on in, most of them have a datasheet you can google and use to get info of have to connect it.

 

Nothing can compare with the feel of a real panel in the simpit :-)

 

If you go for the original connector but lack the external component part., you can use separate wires with crimped female connectors to it (a bit tediuos work just be sure you secure a wires to avoid pull them loose while working on the quad

 

The electronics is the easy part, wish I know the coding part instead :-)

 

Edit: typing on the small buttons of my phone with no glasses is not a good idea. Ignore bad spelling above please

Edited May 2, 2017 by Duckling

[Hansolo]

Thanks Boltz!

Knowing original connectors aren't cheap I was still planing on on using them instead of rewiring the connectors. The extra price payed for the connectors would help offset having to learn how and perform the rewiring of the panels. And while providing no real benefit for the sim it would keep the panels in there original state. A thought I like for whatever reason.

.

You may have to disassembly the entire radio altogether depending on what sort of electrical circuits are in there.

I am not saying this to scare you away from the project however sometimes the panels are design to communicate on a BUS and therefore it probably won't communicate with the Arduino anyway.

 

I would as a kind suggestion try and open up the panel and see what is in there. If it's only switches connected directly to the AMPHENOL connector then it should be fairly easy to map out the pins and reuse the connector. However if you find any circuits in there it may be a lot more difficult.

 

Wiring and mapping out the rotary switches (DIS-CARR-TONE & OFF-T/R-RETRAN-HOME & VOL) should be too bad as long as you IMHO are connected directly to the rotary switches. You may even want to change them out to something less expensive and easier to work with. I did that the rotary for the TACAN as there were too many layer and I gave up trying to figure it out :-)

 

Looking forward to seeing more of your project Sir

 

Cheers

Hans

[Kornskydiver]

I'm on the same boat as you brother! If I can't figure this out soon, I'm gonna have one badass static display :megalol:

[FSFIan]

Something I forgot to mention in my post above: you will also need a soldering iron, as most of the boards you order from China (e.g. an Arduino Nano or the 7-segment display) will not have the pin headers soldered on. It saves them some production cost (through-hole parts generally require hand soldering, while all the surface mount stuff can be placed by a machine) and makes the boards easier to ship in a padded envelope.

 

As you seem to be serious about building more than a few panels, I strongly recommend that you do not skimp on your soldering station. Get a temperature-controlled soldering station from a good brand. In the US, the Hakko FX888D) seem to be popular among hobbyists. Don't buy these from eBay, there are lots of fakes around.

 

Make sure you get a small chisel tip (between 1.2 and 2 mm), the cone shaped ones that most irons come with are crap. If your station does not come with one, get one of those metal-wool tip cleaners. They work better than sponges and you don't have to wet your sponge every time you want to use the iron.

 

If you spend $10 on a cheap mains-connected iron, you will wait minutes for the iron to heat up, have difficulty if you want to use lead free solder, and have a big, heavy iron in your hand that's trying to drag an inflexible mains cable behind it. The stand it comes with will be too light for that iron and you'll have to balance it 'just so'. It's fine if all you want to build is one or two panels, but on a larger project it will slowly drive you insane.

 

Spend around $100 on a good soldering station, and you start to think differently about soldering. The thing heats up within 30 seconds, so you can turn it off after every use. It won't fall out of its stand. The iron itself is small and light, so it is easy to work with. Because the temperature regulation is decent, you can solder different joints back to back without having to wait for the iron to heat up again.

 

The Hakko FX888D seems to cover all the must-have features of an iron for you:

• Heats up within half a minute.
  
• Temperature is adjustable (analog or digital doesn't matter).
  
• Has a way to tell when it has reached the set temperature (digital readout in this case, on analog stations this can be a light that tells you when the heater is on).
  
• Good temperature regulation.
  
• Availability of different tips, and you can be confident that you can still find replacement tips for that iron ten years from now.
  

 

If you spend more money, you will find stations with the following nice-to-have features:

• Sleep mode -- the station will lower the temperature when the iron is placed in the stand. This makes your tips last longer.
  
• Auto power off. If you are not using the iron for some amount of time, it will automatically switch off. A great feature for peace of mind. On the other hand, given a decent stand, a soldering iron is unlikely to burn down your house even if you do forget to turn it off.
  
• Some more expensive stations have the heating element integrated into the tip. This can provide even faster temperature regulation, although the tips are a bit more expensive.
  
• Some stations let you change tips while the iron is hot.
  

 

Personally, I got a used JBC AD2950 soldering station for 240 € from eBay. It has all of the nice-to-have features I listed above.

I would have gone with the Hakko, but IIRC I could not find it around 100 € in Germany and I didn't want to order one from eBay because of the fakes. Ersa and Weller (the two brands that seem to be prevalent in Germany) didn't seem to have anything decent below 300 €.

 

If you buy a decent quality iron and you are not soldering boards on an industrial scale, a soldering station will last you for decades.

Edited May 4, 2017 by [FSF]Ian
fixed list formatting

[nrgized]

Lots of great info guys, thanks!