raptorlogo

Hi Carsten,

Finally I followed your recommandation I bought a Futaba SBS-01G gps.
I do hope a much better satellite fix compared with the F1675 gps.
To me, they seemed to be identical excepted the plastic case.
Regards,
Alain

6396christian

Olkajet, that is very interesting: today i did a taxi-test with the antenna pointing horisontal to the right and taxing on the ground several circles far out to the right ant to the left. On the right hand side i got a high number of "2". I noticed this also on my flights 1-3 on monday that i got several low level RSSIs where the plane was lined up ready for takeoff (therefore my retest on the ground today). Now my observations are also confirmed by your experience. In my logic it should however also have been the case when I was making circels to the far left (bottom of the antenna pointing towards the plane) - but i did not....



After that my antenna was put in upright position, and 2 flights were performed, both with iGyro engaged:



No big RSSI issues today. Perhaps because of antenna position - perhaps because of no military activity. But I am pretty sure the iGyro had nothing to do with my flight 3 issues.

Carsten; here is a map of the military area (approximately) marked with a black line, track is my flight 3:



I really do not know if any activity there could have caused my issues. Anyway I am happy with todays results. My RSSI warning limit is put to below 3 and I will be warned if anything similar happens

Christian

Carsten Groen

Guys,
this is really interesting stuff!
Alain, I think you will see that the SBS-01G has a marginaly better reception, the two planes I have seen here with them shows a better tracking of the satellites if reception quality is not perfect
Christian, very good info on the transmitter antenna, I have mine always horizontal to the right but I also tend to move towards the plane when flying, will be interesting to investigate this further. Ole ("olkajet") will try and mount a ASSI and GPS in a foamy and do some mapping of the signals at his local field (which has a highpower tower 4 km away. The field has some rumor of "radio problems" so interesting to get this mapped.

PS: It would be interesting in the same flight to have the TX antenna in each direction for maybe 1 minute, change direction for the next minute etc, and see the difference


It fills me with joy that the ASSI can be put to some good use

stevekott

That is absolutely great info about the antenna. They are supposed to be omni-directional but they always have a null spot at the tip and especially at the base.

6396Christian, thanks for performing these tests and clearing the iGyro's reputation.

It's great to see it taken out of the theory world and see how this works in the real world. Having this ability to log RSSI goes a long way to dispelling myths and mis-understood facts. Tonight I'm programming my radio to alert below 3! I will also fly with the Tx antenna pointing straight up.

I'm also going to install the SBS-01G gps to compare the GPS speed to compare with the pitot speed and will report.

Thanks Guys for the info!

Steve

Carsten Groen

Just to wrap this one up (I will continue this in a new thread)....

I just received the prototype PCB's for the pressure sensor, soldered one together and it seems to work
I need now to do some small stuff, supporting up to 4 devices in a plane and a few other things then it is done.
Also need to check calibration etc, but so far pretty close

PS: Video still being processed by youtube
A small (very bad!) video of it:

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

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

6396christian

Hi Carsen, Now as I am familiar with RSSI, I look into another issue; my remaining fuel quantity is not really accurate; real consumption was 1,5 liter but reading from ECU/ASSI was 2,6 liter. I guess the logger only collects ECU data, so perhaps any corrections should be done in the JetCat ECU. The JC manual does not cover this - any suggestions?
C

Carsten Groen

Hi Christian,
you are right, I only get the "fuel left" from the ECU, as far as I know there is no user-calibration possible in the ECU
Now, it would be easy to make some kind of calibration in the ASSI device (a factor), but I'm not sure if the error is "constant" or if it changes with the power setting of the turbine...
The ones we have here in Denmark had been pretty accurate, I don't think I have seen anyone with the large of a difference! (according to jetcat it should be around +/- 5%)
If you are doing more tests then please try and see if the error is constant regardless of the powersetting

Rafale Sport

Hi Carsten,
When you set an alarm on the T18 on "fuel left" (vibration), is there a trick to stop the alarm once it passed the low trigger value ? for now my alarm stays on until you land the jet which is really annoying.
Thanks
Laurent

6396christian

Thank you Carsten for your super fast replies (all of them) - yes I will make some more tests an see.
C

Carsten Groen

Laurent,
I don't think so This is a missing feature in the 18MZ (and 14SG) that I hope Futaba will adress in an update. It would be nice if you could "acknowledge" alarms with a configurable switch or something like that

stevekott

Air pressure sensor looks GREAT! Nice Work!

Carsten Groen

Thanks Steve
I just made a combined video that shows both the ASSI, CANLCD and the new pressure sensor. All is working together now
Just wish that Futaba would make some generic sensor types for the transmitter

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

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

ww2birds

My Feedback: (14)

Great work Carsten. Amen on generic sensors, and double amen on "acking" an alarm .. and a related issue .. some alarms (airspeed comes to mind) need an "arming" switch. You would only want to arm a low airspeed sensor once flying. If the radio let you set the retract switch as an arming switch that would be perfect.

I may start a thread on these ideas for our Futaba friends and gather all of our ideas so we can point them to it...

:-)

Keep up the great work Carsten!

Dave

Carsten Groen

Thanks Dave
Good idea on the thread, maybe that can wake them up

Granville.Dunbar

The JetCat mini GSU is a great piece of kit since it can do everything that the standard GSU can, it removes the need for the IO board and is one less thing you need to look after on whilst on the flying field.

It did present a small problem when it came to installing my ASSI since the standard way of connecting this to the ECU is via the IO board which is not installed. However there is a simple solution:
1) On the IO board pins 1 to 6 of the RJ12 connect directly to pins 1 to 6 of both 6 pin flat cable plugs (note that pin 1 is the red wire).
2) The mini GSU has 2 * 6 pin flat cable plugs that are directly interconnected.
3) One of these can be connected directly to the V10 ECU.
4) The second can be connected to the ASSI with wires 6, 1 & 5 of the flat cable connected to Tx, Rx and “-“ on the ASSI (exactly as per the manual pages 20 & 21).

For anyone purchasing a new JetCat, remember that it is possible to order the mini GSU and specifically request that the standard GSU and IO board are not supplied. Not paying for things you don't need almost offsets the cost of the mini GSU and keeps your jet installation a little less busy.

olnico

Hello everyone.
We have the pressure sensors available on our store:

http://www.ultimate-jets.net/collect...ressure-sensor

I have also made a new thread about this product where specific information can be found:
http://www.rcuniverse.com/forum/rc-j...r-carsten.html

raptorlogo

Dear Carsten,

I found out why I had a big difference between the IAS and the ground speed.
I was using the V3 pitot tube (Eagle Tree) with both the static and the pressure outputs.
To me the static measure seems to be wrong
I plugged a tube in the static port of the ASSI and I fitted it into the nose of my plane.
Now I am fully satisfied , the IAS and the ground speed are similar.

My two cents,

Alain

GrahamN

I am just setting up my first (of two) ASSI's
I want to understand how do disable some of the functions, particularly those relating to automatic throttle at this stage. What I want to achieve is to establish the stall speed in the landing configuration, add 30% to that and have an alarm when it goes below this speed.
I assume that I can get the stall speed from the log file (lowest speed in flight)
My preferred alarm would be audio at the transmitter (or in my earphone)

Also has there been any progress with the combined AoA/Pitot tube?
I guess it would be good to also have those warnings with half and no flap in case I have to land in those configurations.

olnico

Hi Graham.
Quote from page 12 of the user manual:
"THR. This is the throttle output from the ASSI device. This will connect to the throttle input on
you JetCat ECU. If you do not want to use the auto throttle function simply leave this connector
unconnected."

The stall speed will be established by doing a stall and having either your spotter to read the value live from the transmitter or reading it yourself from the log after the flight.
Then program the audio alert in your transmitter by adding 30% to the speeds found an entering the value ad hoc, as per instructions on page95 of the Futaba 18MZ user manual.
Futaba has enabled only non conditional audio alerts. So you can set only one threshold value here for one flap setting. I would suggest to use the landing flaps stall speed + 30%.

if you want multiple alerts set according to multiple flaps settings, please use the LED alerting system implemented in the ASSI unit.

Carsten Groen

@Alain: That is great news I guess the tube must be sitting where there are som turbulence in the airstream ? Can you maybe upload a picture of the installation for us to learn from ?

@Graham: As Oli writes, just leave the "Eng" connector unconnected and connect your engines throttle channel directly to your receiver system/powerbox. In the "ASSI Configuration Tool" you can enter 0 in the slot numbers for the telemetry values that you do not need (f.ex the "Target IAS" and the "Mode") then they are not sent to the transmitter.

Kövi

Hi Carsten,

Do you plan to make compatibe your ASSI with Projet hornet ECUs?

Carsten Groen

Hi Kövi,
request for information on their protocol has been sent to Projet some time ago, but so far no response unfortunately...

Ragz

I haven't read this thread entirely..its too long. However I am keen to use this on my Mibo A10. My basic purpose is to get an engine failure alert. I use a futaba 14mz with 3channel receivers with a powerbox royal srs system. The engines are 140rx x 2. Can this unit be used with this setup?
thanks

jcsotto

Talking about protocol, any news on a Jeti version ?
I see more and more DS and DC 16 Jeti transmitter used by RC jet pilot so definitely some potential for your ASSI :-)

The latest firmware from Jeti now support UDI and EX protocol more extensively along with digital in/out entry on receiver so clearly a platform with constant innovation.

http://www.jetimodel.com/en/Telemetry-Protocol/ for documentation on their protocol.

my 2 cents ...

ww2birds

My Feedback: (14)

I am sure Carsten will weigh in shortly .. but .. many (including me!) are interested in this use case around engine failure. Critical for a multiengine model, but still of great interest for single-engine models, including the case of flying with many other jets and you cannot hear your own engine uniquely.

Using the ASSI, you can set alarms in the Futaba telemetry system for several turbine parameters (e.g. vibrate or beep when EGT drops below X degrees, or pump voltage goes to zero, RPM drops, etc).

The interesting question, that has more to do with turbine ops, is what is the best (earliest) indication of a failure (e.g. flameout). Could be the EGT, or, if the ECU shuts down the motor, it could be the pump voltage.

Perhaps some folks have this info so we'd know what to use as the primary alarm for engine failure?

Dave