New Project: Sabreliner 60

[xplanematt]

Here's an unusual one, a North American Sabreliner 60. I have been wanting a real cockpit for a while...this past year I finally got my hands on one! Details here: http://sabrelinersim.com/

Until the shop is built, I can't do a lot with it, though I have been working on interfacing individual gauges, and re-implementing the Trimble GPS in Python (already figured out how to drive the character LED chips that make up the front display). I am hoping to restore power to the cockpit in the next few months, though.

Matt

[Brodhaq]

Hello Matt, you are one of very few people doing it like me and my friends! Awesome I think I must have written the lines on your website about interfacing real gauges via arduino. We have been working on www.dc-9.eu which is in principle very similar to your Sabreliner. Keep us updated please, I will watch your progress 1000 times rather than all the "easy 737 cockpits" all around.

By the way I also have the KLN88 LORAN here on my table but I didnt make it yet. I have studied the installation manual which says it is possible to send lot of stuff there via serial line or via some proprietary protocols (eg. altitude), but the position goes DIRECTLY from antena. So I think the only way would be simulating the actual LORAN signal which would be quite difficult (yet not impossible as far as we have the transmitters position, frequencies and signal format). If you sometimes develop some idea I will be extremely glad to hear it. The bad thing is that even the KLN90 is unable to receive position via NMEA (or whatever) and also receives directly from satelites, which are even much more difficult to simulate than "simple" LORAN beeping.

Pavel

[xplanematt]

Hi Pavel, NICE WORK!!!! That is truly an amazing cockpit you have there! Always good to see real stuff, especially something so complete. I will be interested in following your progress also, especially as to how you interface some of those real parts. Your altitude alerter looks (internally) a lot like mine.....have you decided how to interface it yet? I am working on an Arduino interface to read the position of synchros and resolvers...it's slow but steady progress, I have a lot to learn about electrical engineering.

I'm amazed you got your ARINC radio heads interfaced using OpenCockpits and SIOC...that SIOC script makes my head spin!!!! I'm using a Python script and X-Plane's API to run my radios (the dictionary object in Python is wonderful). Looks like you've been able to dig into the internal workings of those radios more than I have. I understand the basic concept, but the actual wiring and mechanics inside still remain a mystery. All I know is I read highs and lows on the rear connectors and get a frequency reading. It's interesting that your flip-flop function requires reading of both active and standby frequencies. The 737 COM I did (Collins) only had one set of outputs for frequency, flipping the XFR switch actually changed the states of the output pins. Again, I do not know how they do it, I just know it saved me a lot of wiring. I assume you are using factory pin-out diagrams for the control heads, no?

How are things going on your analog gauges so far? Are you only working with D'Arsonval instruments at this point, driving them with PWM from the Arduino? I have found some temp gauges are D'Arsonval, but are designed to measure very narrow voltage variations (basically, the temp probe is a variable resistor, which changes with temperature). On those I just have to use a bias resistor to be able to use the full PWM range of the Arduino. In fact, my wife got me a radar altimeter for Christmas (yes, she is awesome!!!) and it appears to use the same setup....I put 5v to it and the needle IMMEDIATELY slammed from full-scale deflection to zero. Interesting.

Are your engine gauges synchro based? I have friends running synchro instruments, they are using servos to move synchros that function as control transmitters, wired to the synchros inside the engine instruments. I would like to figure out a way to drive synchros digitally, so multiple-turn instruments (like HSIs) will work correctly. That is part of my current synchro/resolver research.

Last weekend I restored partial power to the cockpit:

http://sabrelinersim.com/powered/Center.jpg

http://sabrelinersim.com/powered/sab..._ice_light.jpg

http://www.youtube.com/watch?v=hVh3Zr-PS0U

On the KLN88, I have given up interfacing it for now. It does have serial inputs/outputs, but it's for stuff like fuel data computers and Argus moving maps. You can't feed it lat/lon data. HOWEVER, I have since started re-implementing the Trimble 3100T operating software in Python....and it's going great! I already have a bunch of neat functions working, like calculating speed and course only by referencing lat/lon readings at specific intervals Once the software is done, I will "break" the real Trimble GPS and install a Raspberry Pi and Arduino to read the buttons/knobs, and drive the display. And since the Argus moving maps are designed to accept serial input anyway, I should be able to drive something like an Argus 3000 ad have a fully functional moving map later on. Fun stuff.

[Brodhaq]

Hi, sorry I didnt notice your post here since we were e-mailing:

1) altitude alert - exactly the same, arduino here as well...
2) The control heads are not ARINC nor SIOC... When I was working on them we had no factory information so I have just deassembled them to the last screw to look how do they work. They are mechanically very amazing so we didnt touch it. But the internal wiring is fully custom and we have connected it to joystick cards (custom build, just generic 64-inputs joy cards) which is being decoded by custom script in the PC.
3) The engine instruments are all 100% resolved and working. We use only Arduino to controll them - where they need some power which can not be delivered by arduino we use H-Bridge to boost the signal. Even the synchros are fully interfaced by my friend Jindrich.

If I am not mistaken the fuel flow gauge in our project is repeated-based, that is probably what you call synchro. The rotor has a permanent magnet. There are two coils by 90°. By applying load to the coils the rotor turns to the direction of the strongest magnetic field. By varying combination of loads we can reach 8 basic positions in the whole range by 45° in those combinations:
A B
00 01
00 10
01 00
01 10
01 01
10 00
10 10
10 01
Between those combinations we can reach any intermediate position by changing the load. Because the coils need to be loaded in both directions each of the is connected to two outputs on a H-bridge (with 100Ohm resistor). The arduino calculates the required load for each coil and controls the H-Bridge accordingly (4 H-bridge modules in total). Credits for this research: Jindřich Machalinek, DC-9 project member.

Pavel

[xplanematt]

Wow, your friend is reading the synchros in the altitude alerter? I would love to chat with him about this! I need to read my alerter this way, and I also need to read synchros in my altimeters. I have had some success, but I am not able to fully analyze the AC wave forms. I have had some assistance from another Arduino guy, and I think with the info he gave me I will be able to read synchros/resolvers and also position them digitally, but it would sure be helpful to talk to someone who has actually done it.

Your engine instruments sound an awful lot like air core motors, not synchros. Synchros typically have 3 coils at 120* spacing, or two coils that react with the stator, and they always use AC voltages. I have a Cessna flap gauge that seems to be using something like an air core. I REALLY like air cores because they are simple to drive and require no special circuits beyond a simple H-bridge array (I am using the L293D chip). That's good news, if all my engine gauges are air-core'ish then they will be easy to drive with the Arduino.

On the radios, I bet your digit groups actually correspond to ARINC patterns. Transponders in particular use an ARINC "2 of 5" scheme. This isn't critical to know since we are making our own interfaces, it's just interesting info. I managed to get the pin-out diagrams on all the radios I've interfaced thus far, which allowed me to keep the radios unmodified and use the original airframe-side harness (when it was available, mainly on the 737....on my own sim, I did have to cut out the original Canon connectors because I did not have the other end of the connector). My Sabreliner uses Collins gear (as the 737 did), so I am hopeful the folks I contacted there can get me all the paperwork on my Sabreliner gear also...hopefully even the AP-104 IFCS flight manual!

[xplanematt]

Just a tiny update...I have been working on bits and pieces here and there, but not a lot of stuff that is post-worthy. I did finally get my hands on a matching pair of EGT gauges that have almost exactly the correct green arc and redlines for the Sabreliner 60, also picked up a hefty 27.2v PSU on ebay that seems to power the cockpit and one inverter (which is all I should need) with ease...a good thing!

There is one really cool project I got working: Argus moving map! Yep, the Sabreliner will have a real, unmodified, fully functional Argus 7000 which will go hand-in-hand with my rebuilt Trimble GPS:

https://www.youtube.com/watch?v=fgXTDSQ8IAE

Fun stuff!