Futaba SBUS2 telemetry,JetCat ECU,IAS and AoA indicator/warn, autothrottle, datalog
 

I have been working on a small "combined" device for my jets (and maybe others too)
(The work is a offspin of this thread: New product – ASSI – AirSpeed and Stall Sensor - RCU Forums)

The device contains a number of subsystems:

"ASSI" (AoA and IAS warning/autothrottle system):
1) Indicated Airspeed (max 480 km/h / 1040 km/h)
2) Angle of attack from -20 to +20 deg, with 1 deg resolution (only used for warning/logging at the moment)
3) Autothrottle function (minimum airspeed for up to 5 flap positions, each is teached during flight by pilot)
4) Warning for airspeed or AoA (with red and green high bright LEDøs)
5) Presettable airspeed (set a target airspeed on your transmitter with a knob, and the will maintain the speed)

"ECU" (Data from JetCat ECU):
1) Fuel left in tank
2) Current EGT
3) Current RPM
4) Current ECU battery voltage

"SBUS2" (Futaba telemetry, 11 sensor slots used, slot 20 to 31 with 1 not used):
1) ECU: Fuel left (in mL)
2) ECU: Current RPM
3) ECU: EGT (in deg Cel)
4) ECU: battery voltage (in 0.1V)
5) ASSI: IAS (in km/h)
6) ASSI: AoA (in degrees)
7) ASSI: Maximum airspeed during current flight (in km/h)
8) ASSI: Current mode for ASSI system (0=disable, 1=normal, 2=autothrottle)
9) ASSI: Preset airspeed (set by knob on transmitter, 0..250 km/h)
10) RX: Failsafe counts
11) RX: RSSI (Signal strength, 0..3, the receiver sees the transmitter with, 0=poor, 3=good)

"AUX COM" (CAN bus for other systems, LCD screen, GPS, pressure sensor for retracts etc)

"DATALOG" (a datalogger that stores all data (including servo positions, ECU data, IAS/AoA, failsafe counts etc in a text file on the SD card)

Physical interfaces:
1) SBUS2 connector to receiver
2) Battery (2S LiPo), good if high power LED's are used for the ASSI IAS/AoA waring system. Will auto poweroff when receiver is powered down
3) JetCat ECU connection (connects to the GSU port)
4) Throttle output (used when using the autothrottle). This simply outputs channel 3 from the transmitter
5) 2 Highpower LED outputs. Must use a limiting resistor in series. Max 1 amp per output, pulls output to ground
6) CAN Bus interface for other devices*
7) 3 LED's on board (diagnostics etc)
8) SD Card interface for micro SD card



All of the above is working now on my "version 2 prototype board".
I have been running lots of tests on the ASSI subsystem (in my Sprint using a P100RX engine), and it seems that the waring system and autothrottle works very well! The AoA waring system is currently not used actively in flight, but the data is logged. The systems can be disabled one by one (f.ex in a dual engine system, it is possible to only enable the ECU interface and SBUS2 telemtry on the second device).
The "ECU" subsystem was tested this last week by my friend Kasper Holger (CarbonCustoms) in his F16 with a P300RX engine. Fuel indication was very precise! We programmed a warning on the transmitter when there was less than 1 liter left of fuel, worked like a charm!
The IAS indicator is limited to 480 km/h (approx), can be ordered with a sensor capable of 1040 km/H

Unfortunately, because of the Futaba telemetry implementation in their transmitters, one have to use some of their sensors for the various paramters. I use their "RPM" and "TEMP" sensors, this has the effect that the units are "RPM" and "degC" fixed in them. It would have been nice if they had made a "generic" value, one without any unit behind it, one can only hope :)

Currently trying to decide if this is something that should be brought to the market, and how that could be done ?
More to come when I have done some more testing in the following couple of weeks!

Manual available here: https://dl.dropboxusercontent.com/u/93706850/ASSI.pdf

Pictures of the device:
*

RE: Futaba SBUS2 telemetry, JetCat ECU, IAS and AoA indicator/warning, autothrottle and datalogger
 

Once you are done beta'ing it, and should you decide to bring it to market (you should), you can count me in for at least three of them.<div>Telemetry doesn't seem to be a big priority for Futaba at this point (took me a year to get a GPS sensor) so it is great to outside innovation such as yours.</div><div></div><div>David</div><div></div>

RE: Futaba SBUS2 telemetry, JetCat ECU, IAS and AoA indicator/warning, autothrottle and datalogger
 

Cool stuff Carsten.

After a recent investment in an 18MZ, I have been wondering what relevant telemetry systems I could add. I'm struggling with how to use these add-ons without increasing the "pilot load" to the point where it's counter productive. The autothrottle sounds like a good idea as do some of the others.

If you find a way to bring it to the market, I'm sure there will be buyers but probably limited - divide whatever people say on the forums by 10. Maybe suggest to Futaba to add a generic value in thier next software release.

PaulD

RE: Futaba SBUS2 telemetry, JetCat ECU, IAS and AoA indicator/warning, autothrottle and datalogger
 

Thanks David and Paul!
And yes Paul, you are correct about the workload of the pilot, I'm one of the types that don't even dare to look at the screen to see the timer :D
The good thing is that you can assign a switch to the most important things (like fuel left in the tank), and have the friendly lady read the numbers for you so you don't have to take your eyes off the plane.
Also the IAS it is easy to set an upper limit with a warning so you don't overstress the airframe (same with the AoA warning).
The device uses two bright LED's for the IAS warning thing also, when on final you look (extremely focused :D) at the plane, and the two LED's are very easy to see (they use blink pattern to tell you if you are above/below the programmed/teached airspeed with the current flap config). If the autothrottle is active, you don't even have to look at the LED's as the system handles the throttle and makes sure that the plane does not fall "out of the sky" ;)

The logged data looks like this (probably will change a bit, also looking into if it would be nice to log data from all the other SBUS devices, GPS etc):
(sorry for the formatting..)


Time: RXbatt: RSSI: FSafe: Mode: IAS: AoA: ENG: Fuel: RPM: EGT: ECU: [01]: [02]: [03]: [04]: [05]: [06]: [07]: [08]: [09]: [10]: [11]: [12]: [13]: [14]: [15]: [16]: [DG1]: [DG2]:
Sec 0.1V 0..3 0..n 0..3 km/h deg uSec mL n degC 0.1V - Channel 1 to 16 is counts from 0 to 2048 (1024 is center), DG1 and DG2 is 0 or 1 -
1 52 3 0 0 0 0 2000 0 0 0 0 -1 0 101 0 47 -102 -1 -1 -1 -1 -1 -1 20 -102 -1 -1 0 0
2 52 3 0 0 0 0 2000 0 0 0 0 -1 0 101 0 47 -102 -1 -1 -1 -1 -1 -1 20 -102 -1 -1 0 0
3 52 3 0 0 0 0 2000 0 0 0 0 -1 0 101 0 47 -102 -1 -1 -1 -1 -1 -1 20 -102 -1 -1 0 0
4 52 3 0 0 0 0 2000 0 0 0 0 -1 0 101 0 47 -102 -1 -1 -1 -1 -1 -1 20 -102 -1 -1 0 0
5 52 3 0 0 0 0 2000 0 0 0 0 -1 0 101 0 47 -102 -1 -1 -1 -1 -1 -1 20 -102 -1 -1 0 0
6 52 3 0 0 0 0 2000 0 0 0 0 -1 0 101 0 47 -102 -1 -1 -1 -1 -1 -1 20 -102 -1 -1 0 0
7 52 3 0 0 0 0 2000 0 0 0 0 -1 0 101 0 47 -102 -1 -1 -1 -1 -1 -1 20 -102 -1 -1 0 0
8 52 3 0 0 0 0 2000 0 0 0 0 -1 0 101 0 47 -102 -1 -1 -1 -1 -1 -1 20 -102 -1 -1 0 0
9 52 3 0 0 0 0 2000 0 0 0 0 -1 0 101 0 47 -102 -1 -1 -1 -1 -1 -1 20 -102 -1 -1 0 0
10 52 3 0 0 0 0 2000 0 0 0 0 -1 0 101 0 47 -102 -1 -1 -1 -1 -1 -1 20 -102 -1 -1 0 0
11 52 3 0 0 42 0 2000 0 0 0 0 -1 0 101 0 47 -102 -1 -1 -1 -1 -1 -1 20 -102 -1 -1 0 0

RE: Futaba SBUS2 telemetry, JetCat ECU, IAS and AoA indicator/warning, autothrottle and datalogger
 

This is really cool. I have been a little disappointed in the lack of telemetry items for the 18MZ. The lack of a simple plug and play airspeed sensor is a perfect example.

RE: Futaba SBUS2 telemetry, JetCat ECU, IAS and AoA indicator/warning, autothrottle and datalogger
 

Carsten - I am pleased and impressed with your progress. I am currently test flying a telemetry unit that was designed by Jim Shima in a prop plane. This unit gives me air speed, flame out warning and stall warning verbaly with an earphone. If tests go well this week I will move the unit to my Boomerang for testing in a jet model.

Been doing some more stuff with the device, the logfile as mentioned before, contains data for all sensors on the SBUS2. One of my friends did a testflight with his Futaba/Robbe GPS unit in the plane, my device logged all the data from the GPS during the flight (as well as G forces, turbine data, servo positions, receiver voltage, signal strength, failsafes etc.
I have made a small application that can help with the configuration of the device, and which also can decode the compressed txt logfile from the device. One of the outputs is a KML file for Google Earth
(the straight lines a few places on the google track is because the GPS receiver lost fix a few times)

I hope to make the KML file so that you can click on each point (1 sec log intervals) and get a popup box with airspeed, G force, Angle of attack etc.
The height measurements are from the GPS's builtin vario sensor
PS: Flameout sensor on this device is as simple as setting a low level for the EGT temperature in the radio :)

this system really rocks... the fuel left system is fantastic!

Are you planning to take this gadget to the market ? if yes, when do you think it could be available ?

Hi Carsten. Great work! I am amazed at the talent that some of you guys possess. Keep going with this! It wasn't that long ago that people weren't using gyros in jets and now we have 3 axis systems out there. Soon it will be common place to have IAS, fuel left, batt voltage etc for ecu. Count me in!

I got an IAS sensor from a guy in Germany. Works well!

Thanks for the kind words guys :)
I have some small things to change on the prototypes (change so all the connectors are the same type, going for "servo connectors" type for all of the connectors, and then I will make a small number of boards to test on. Then hopefully production can start sometime during this fall.
Craig, I have been doing embedded systems for 30+ years, so "talent" has nothing to do with it :D

I'm only a little sorry that Futaba has not made any "generic/typeless" sensor for the 18MZ (and 14SG) on their transmitter, that way I would not have to have "degC" on all the numbers, looks bad to my eyes :(
Anyway, it's only cosmetic, and hopefully they will make such a "sensor type" once they realize that others than themself are doing telemetri units for their transmitters...

Carsten,

Just tell them "degC" means "really fast" in Danish. :)

PaulD

Paul,
thanks a lot for the good idea, I'll write that in the documentation :D

Nice work Carsten! While we're at it, how about two more wishlist items for telemetry: 1) in addition to your "typeless" ask, how about being able to scale and offset e..g Y=aX+B where Y is the displayed output and X is the input so we could display in convenient units and 2) the ability to use telemetry data to control TX functions ..e.g mix to channels or "throw" switches .. the possibilities there would be pretty cool :-)

Dave

Wow this will be excellent!

Thanks Dave :)
Oh yes, that would be nice, especially the ability to use a telemetry value as input to functions same way as sliders/knobs and switches!
Good idea!

This system is a must for all jetpilots.. Have the honor to have a test version in my Eurosport.. it works like a charm :D Fuel warning @ 500 ml, IAS & G force directly onscreen.. When hitting a switch the nice lady tells me rest of fuel..

Please hit the market wih this! - I´ll need it for my 4 jets :cool:

Hello Carsten
With the A10 you'll be higtly concerned with the disymetry caused by an engine flame out.
Is your system able to inform you of a flame out, with aural indication of left or right engine shut down ?
Best regards
Stan

Hello Stan,
anything is possible :)
I have actually thought of this as I'm also building a Mibo A10, you can certainly use two of the devices on the bus, no problem. I'm thinking of making a option for this, a seperate telemetry channel that will tell which engine flames out (I would guess with a delay of max 1 second). You will then just make a warning on that telemetry value, normally it would be 3 (both engines on), and if engine 1 flames out, the display would read "1", if number 2 dies, it would show "2". You would then just set a alarm threshold on that telemetry value so that if it ever goes below 3, the nice lady inside the 18MZ would begin yelling at you "2" or "1" :D
Unfortunately, she would also say "degress", but that is due to the missing flexibility of the 18MZ (there is no "generic" number/sensor, hopefully that will come at some point ????)

Carsten:

Your device is only going to work with Jetcat ? No intentions of expanding to some other brands like Jetcentral ?

Anyway... I'm in. Whenever you have your device ready put me in the list with three (3) of them. If you decide to expand it to Jetcentral latter, you can add several more.

I'm currently using Robbe Futaba Telemetry with my 18MZ and Robbe Telemetry box, but for sure I can use something more powerful.

Gonzalo,
well, as it is right now, it's only JetCat. But, if f.ex JetCentral is open about the protocol they use, and the hardware in my device is compatible, I don't see why it should not be possible to include that one also!
If any of you have some info on the JetCentral ECU/comms, please let me know !

Carsten:

Please let me know what kind of info you need by PM. I do have good contacts with them so I can see if they are willing to share their info. I will also check if Gaspar from www.xicoy.com is still making the FADEC's for them. He could be the man to talk to.

Gonzalo,
PM sent :D

Nice device there Carsten, if you get it working with the Xicoy Ecu then u would have Kingtech and Wren covered also! Since they all use Xicoy ECUs.