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Old Jul 30, 2011, 12:32 PM
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I hope Mr. Wu will not forget the recording of the datas for his next display, (black box !)
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Old Jul 30, 2011, 01:55 PM
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Belgique, Région Wallonne, Liège
Joined May 2009
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Quote:
Originally Posted by michel49 View Post
I hope Mr. Wu will not forget the recording of the datas for his next display, (black box !)
Maybe I am wrong in thinking these accelerometer informations are not interesting but I was told the system would be able to record these datas on one SD card for future use, and that's the reason why I mentionned it.
If you believe that I am asking to record anything in a ' black box' as you wrote, this is totally wrong and I am sorry about this misunderstanding,
english is not my first language.

There is however one information that will be stored in the DHT-U if you have the GPS connected to the hub: the last position.
This could be interesting to locate your model should it fly away out of control and be lost.
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Old Jul 30, 2011, 01:55 PM
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Germany, lake of constance
Joined Oct 2010
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Hi CaptainBlueSky

I think as you have mentioned, data like accX, accY,accZ, lontitude, latitude, etc are not very useful during flight. It is
better to save those and other data on a SD card for post flight analysis. During flight it is impossible to look on all this data.

A good thing wood be a current sensor like the ACS 758. So used mAh can be caculated as well as motor input power if using also a voltage sensor.
Next thing would be to store battery min voltage , max values of I and Pin.

The display should show primary data on first page like battery voltage, mAh and or fuel level.

Best regards
Micha
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Old Jul 30, 2011, 02:37 PM
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Originally Posted by snoopy_schulz View Post
Hi CaptainBlueSky


The display should show primary data on first page like battery voltage, mAh and or fuel level.

Best regards
Micha
Thank you Micha,
I was suggesting battery voltage in the lower middel position between the two RSSI informations.(Maybe better in right bottom corner as fuel is in right top corner?)
Fuel level or Battery level, from calculated mAh used as you say, on right top corner.(As it is now)
The fuel indication, according to the Frame Protocol, is sent as a % value, so I am wondering why they choose to show only 1/4 steps and asked if it would be practical to start showing in 2 digits from 25 % and lower ( How about two large blinking digits when under a preset value like 15 or 10 % ?)

Best regards,
Al
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Old Jul 30, 2011, 09:21 PM
Sudden Freak
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Atlanta, GA
Joined Oct 2006
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Searching Google Images for "telemetry screen" gives quite a few of good examples on how other manufacturers designed their screen layout, including Aurora, Spektrum, Quanum, etc.
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Old Jul 30, 2011, 09:25 PM
Martin - AKA mr.sneezy
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Adelaide, Australia
Joined May 2004
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Quote:
Originally Posted by CaptainBlueSky View Post
Maybe I am wrong in thinking these accelerometer informations are not interesting.

There is however one information that will be stored in the DHT-U if you have the GPS connected to the hub: the last position.
This could be interesting to locate your model should it fly away out of control and be lost.
I'm glad you've come out with some open views about the Acc sensor. I didn't want to say it before exploring all the uses of it, but frankly I think it could be dropped from the display data, and I'm not fussed if it's dropped off the telemetry stream altogether. Unless somebody comes up with a 'real-time' usage for it.

I'd find a current sensor much more useful too, especially if used with used mAh calculation. Along with the voltage alarms, it should be very hard to run out of flight battery accidentally then.

While watching the screen is hard while flying, nobody ever said you can't land, look at the screen (voltage etc), then take off again
I do that now with my Heli.
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Old Jul 31, 2011, 02:15 AM
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Hi to all, I am new in this forum. I am very interested to buy a complete frsky telemetry system. I would like to integrate the telemetry system using my Futaba 3 PK for car applications. So, I thinked to buy the DJT system using V8R4 receivers for my cars.
My target is to receive rpms, voltage of 2 lipo batteries, 2 temperatures (esc and motor) in real time into DHT-U display.

Tell that, I have some doubts, please someone could provide me the answers?

1 - Can I use rpms sensors NOT frSky brand (for example Aitronics or Eagle Tree)?
Exist a particular data transfer protocol because I need only frSky sensors?
I need a sensor able to calculate > 60000 rpms.

2 - Can I see the live telemetry data NOT using DHT-U display?Or I
need mandatory it? In other words, could I receive the live telemetry
data directly on my futaba 3 pk display?

3 - Which is the refresh time of the rpms (or speed) and temperatures
live data on DHT-U display? It depend from latency time (22 ms) of the
receiver?

4 - Can I use concurrently "FrSky Two-way 2.4G Module W/LCD Display
DHT-U" and "DJT Category:2.4GHz Two Way Series transmitter module"? I
mean, can I use Display DHT-U to receive the telemetry data and to use
the DJT module to move the car model? Do I need to link the DHT-U display
with DJT tx module?

Thank you so much in advance
Daniele from Italy
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Old Jul 31, 2011, 02:58 AM
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Romania, Dolj, Craiova
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Unfortunately, too many NO/unknowns to your questions.
First of all, V8R4 receiver will not give you telemetry.
For the rest, there is need of a lot of investigations to reply, system is too new.
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Old Jul 31, 2011, 03:32 AM
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Originally Posted by RENATOA View Post
Unfortunately, too many NO/unknowns to your questions.
First of all, V8R4 receiver will not give you telemetry.
For the rest, there is need of a lot of investigations to reply, system is too new.
Hello Renatoa,

thank you for your answer.
It was my mistake. I would liked write this code D4FR for the used receivers.

I will wait possible news.
have a good day
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Old Jul 31, 2011, 04:53 AM
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Quote:
Originally Posted by danitaly View Post
My target is to receive rpms, voltage of 2 lipo batteries, 2 temperatures (esc and motor) in real time into DHT-U display.

4 - Can I use concurrently "FrSky Two-way 2.4G Module W/LCD Display
DHT-U" and "DJT Category:2.4GHz Two Way Series transmitter module"? I
mean, can I use Display DHT-U to receive the telemetry data and to use
the DJT module to move the car model? Do I need to link the DHT-U display
with DJT tx module?
You don't need the DJT module as DHT-U is not only a display but it includes 8 Ch. 2.4 GHz Tx module which is
able to work with every ACCST receiver from FrSky. Of course Telemetry will work only with telemetry receivers like the D8R, D6FR and D4FR.
I you want to show RPM or T°, you need the HUB, and for the moment FrSky HUB will work only with DHT-U

Quote:
Originally Posted by danitaly View Post

1 - Can I use rpms sensors NOT frSky brand (for example Aitronics or Eagle Tree)?
Exist a particular data transfer protocol because I need only frSky sensors?
I need a sensor able to calculate > 60000 rpms.
Frame Protocole is available as download, from FrSky web site.

Quote:
Originally Posted by danitaly View Post
2 - Can I see the live telemetry data NOT using DHT-U display?Or I
need mandatory it? In other words, could I receive the live telemetry
data directly on my futaba 3 pk display?
No, it is always possible ( any LCD display will show any info you send in the correct format) but this would be a DIY solution and would require too much work only to avoid using an additional display.

Quote:
Originally Posted by danitaly View Post
3 - Which is the refresh time of the rpms (or speed) and temperatures
live data on DHT-U display? It depend from latency time (22 ms) of the
receiver?
See Frame Protocole

[QUOTE=danitaly;18912211]

Note:[/U]

Basic display ( without HUB and sensors) includes the analog voltages A1 and A2 ( direct input in Rx / max 3.3 volts) and you can select divider in setting page for these voltage displays, so there are a lot of possibilities for various inputs
I expect also FrSky to implement in the near future a dedicated page for detailed Lipo's datas, cell by cell.

Regards,
Al
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Old Jul 31, 2011, 05:47 AM
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Al, thank you so much, now it is more clear for me.
So, I will use only the the frsky display.

I think and I hope, the frsky manual will explain me as I can to link 3 PK to frsky display.

Anyway, with the frsky protocol I am not able to understand if I can to use rpm sensors NOT frSky brand.
Do you know, for example if I could to fit Eagle tree RPM-KIT-MAG magnet rpm sensor into frsky hub sensor?
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Old Jul 31, 2011, 05:58 AM
Martin - AKA mr.sneezy
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Adelaide, Australia
Joined May 2004
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GPS receiver sensor info

I got time to do some checking of the GPS receiver this week as far as functionality goes. And it goes well....

Lock time from cold start varies a little, but the longest time was around 60 seconds, and the shortest around 20 seconds.

The GPS obviously feeds the Speed display and the Lat Long coordinates, but it does not feed the Altitude value, even if the Vario barometric sensor is unplugged.
It would be nice to also have GPS altitude as another reference I think, even though it's not as accurate as it's horizontal position. The Hub could use either source possibly if so programmed, and feed the altitude data in the stream on the same DataID as the baro sensor would if fitted. It could default to using the barometric sensor in preference though if GPS is on the hub as well.

Martin
PS. While playing with the barometric altimeter (Vario) I note that the altitude data update is quite fast, perhaps three times a second roughly. I think somebody asked about the refresh speed...
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Old Jul 31, 2011, 07:27 AM
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Gratens, little place around Toulouse...
Joined Dec 2007
399 Posts
HI there,

Does anyone have all sensors availble and can capture the output data from the Frsky Hub with a serial interface ?

I do not have the GPS and i miss one temp sensor. I also don't have the rpm sensor too.

The goal is to get the full datagram.

And then, make a removable of each sensor, and record it again in a new file to see the difference between each datagram.

If someone can do this by removing all sensors one by one and send me the result on my email adress, i could have a good news very soon for anyone here...

Note : Each sensor removal, means new file. There are 8 sensors, so there should be 9 files.

Kind regards.
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Old Jul 31, 2011, 07:40 AM
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Belgique, Région Wallonne, Liège
Joined May 2009
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This will answer some timing questions about RPM, altimeter and other.
According to the Frame Protocol given by FrSky:

There are 3 frame types:


FRAME1 = 200ms( 5 per sec),FRAME 2 = 1 per second and FRAME 3= 1 every 5 seconds
Frame1
Three-axis acceleration value,Altitude( baro),Temperature1, Temperature2, volt,RPM.

Frame2

course,latitude,longtitude,speed,Altitude(GPS) ,fuel_level

Frame3
date,time


Note that Altitude ( from GPS) is also transmitted but not used so far. Same applies for Heading (course).

Al
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Old Jul 31, 2011, 12:54 PM
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Joined Jul 2011
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Quote:
Originally Posted by CaptainBlueSky View Post
This will answer some timing questions about RPM, altimeter and other.
According to the Frame Protocol given by FrSky:

There are 3 frame types:


FRAME1 = 200ms( 5 per sec),FRAME 2 = 1 per second and FRAME 3= 1 every 5 seconds
Frame1
Three-axis acceleration value,Altitude( baro),Temperature1, Temperature2, volt,RPM.

Frame2

course,latitude,longtitude,speed,Altitude(GPS) ,fuel_level

Frame3
date,time


Note that Altitude ( from GPS) is also transmitted but not used so far. Same applies for Heading (course).

Al
hi Al

very very interesting, thank you for this other answer to my questions.

I will wait kindly also the opinion of someone that tested frsky system with rpm/temperatures sensors NOT frsky brand.
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