OpenXVario HOTT Support

Development & General Chat for the superb openxvario project.

Moderator: rainer

Post Reply
Jochen222
Posts: 1
Joined: Sat Jun 22, 2013 9:51 pm
Country: -

OpenXVario HOTT Support

Post by Jochen222 » Wed Jun 26, 2013 11:48 am

Hi,

I´v seen an the code there´s Jeti protocol support for the xvario.

I use the Graupner HOTT telemetry system and found the OpenXVario project with the high resolution MS5611 very cool. Is ther something planned to add HOTT support (I´m not a good programmer)?

There are some projects which maybe have usable code snippets for the proctol:
https://code.google.com/p/diy-hott-gps/
https://github.com/obayer/MultiWii-HoTT
https://github.com/cGiesen/MultiHoTT-Module
http://code.google.com/p/hott-for-ardupilot/
MAVLINK2HOTT: http://autoquad.org/wp-content/plugins/ ... .php?id=31

Jochen

User avatar
rainer
Posts: 391
Joined: Tue Jan 01, 2013 9:20 pm
Country: Germany
Location: near Düsseldorf

Re: OpenXVario HOTT Support

Post by rainer » Wed Jun 26, 2013 11:56 am

Hi Jochen,
the upcoming new version called openXsensor will have exchangeable output modules, so technically only one class has to be adapted. i don't have any Graupner HW, so we would need somebody with the HW to give it a try. If you want to try, i would be willing to help you.
rainer.
build your own vario ==> https://github.com/openXsensor/openXsensor/wiki (Formerly https://code.google.com/p/openxsensor/ and https://code.google.com/p/openxvario/)

Spitpt
Posts: 5
Joined: Thu Mar 23, 2017 8:44 pm
Country: -

Re: OpenXSensor V8 HOTT Support

Post by Spitpt » Thu Mar 23, 2017 8:53 pm

Hello,

I'm a Hott telemetry system user and I'm trying to implement the OpenXsensor V8 but I don't have any sensor that appear on the transmitter screen.

My setup is Arduino Nano pro mini 5v 16 Mhz with a BMP180 and Neo6 GPS on a GR12 receiver. Is there something more to do than changing the PROTOCOL name and Pin configuration?

Thank you for helping.

Bess regards.

mstrens
Posts: 1056
Joined: Fri Dec 27, 2013 7:49 pm
Country: -

Re: OpenXSensor V8 HOTT Support

Post by mstrens » Thu Mar 23, 2017 9:24 pm

Spitpt wrote:
Thu Mar 23, 2017 8:53 pm
Hello,

I'm a Hott telemetry system user and I'm trying to implement the OpenXsensor V8 but I don't have any sensor that appear on the transmitter screen.

My setup is Arduino Nano pro mini 5v 16 Mhz with a BMP180 and Neo6 GPS on a GR12 receiver. Is there something more to do than changing the PROTOCOL name and Pin configuration?

Thank you for helping.

Bess regards.
Can you send me the file oXs_config.h that you are using. I can check if it is OK.

Spitpt
Posts: 5
Joined: Thu Mar 23, 2017 8:44 pm
Country: -

Re: OpenXVario HOTT Support

Post by Spitpt » Fri Mar 24, 2017 6:15 pm

Hello,

I'd just send you the file.

Thanks for the help.


Spitpt
Posts: 5
Joined: Thu Mar 23, 2017 8:44 pm
Country: -

Re: OpenXVario HOTT Support

Post by Spitpt » Fri Mar 24, 2017 8:26 pm

Thank you for the file but the problem stay the same. In facts, on the Hott system, you have an auto detection of the different modules that you connect to the Hott receiver. This autorise to select then a screen in relation with the module and only tghese screens. For exemple, if you connect only the gps module, you can't see the screen with cells voltages.
In my case, the information about the connect module doesn't appear. It 's looking like there is no module. (the same think with the V7).
I'll trying older versions to see if there's one working and trying to find the eventual differences in your code. Maybe there is a wiring problem but i'd followed yours indications:
Port 4(Tx port) of the arduino to the T of the telemetry data port. There isn't Rx port from the arduino to the receiver?

Best regards.

Carbo
Posts: 241
Joined: Fri Aug 02, 2013 6:55 pm
Country: -

Re: OpenXVario HOTT Support

Post by Carbo » Fri Mar 24, 2017 8:46 pm

I am not a HOTT user, but i think GR12 requires a pullup resistor:
http://fpv-community.de/showthread.php? ... post899651
or better here, the second drawing:
http://fpv-community.de/showthread.php? ... post899893

mstrens
Posts: 1056
Joined: Fri Dec 27, 2013 7:49 pm
Country: -

Re: OpenXVario HOTT Support

Post by mstrens » Fri Mar 24, 2017 9:07 pm

If I understand it right, the second schema is not really a pull up but
- a pull down (when Arduino does not force a voltage, Rx will get 0 volt)
and
- a voltage divider.
I think that this schema has been proposed in order to avoid that when oXs forces 5 volt, then the rx will only get 3.3 volt what is for sure safe ( to protect the Rx if there is no other protection on Rx side).

Carbo
Posts: 241
Joined: Fri Aug 02, 2013 6:55 pm
Country: -

Re: OpenXVario HOTT Support

Post by Carbo » Fri Mar 24, 2017 9:39 pm

This was foreseen as a universal version, that should work with all Graupner RX - at least it does not damage anything :) It worked, but nobody understood exactly why. Maybe you can explain it.
Teiler.png
© Stoschek@fpv-community.de ;)
Last edited by Carbo on Sun Mar 26, 2017 10:20 am, edited 1 time in total.

mstrens
Posts: 1056
Joined: Fri Dec 27, 2013 7:49 pm
Country: -

Re: OpenXVario HOTT Support

Post by mstrens » Sat Mar 25, 2017 8:31 am

Initially I looked at another schema in the link.
Indeed the schema here above should work and be safe.
The signal between Arduino (e.g. D4) and Rx is controlled by the 2 components (Arduino and Rx) because it is bidirectional.
It is important to ensure that there are no damage if by mistake each component try to force a different voltage.
To avoid damage, it is foreseen that each component can drive the voltage level to ground but can't drive it to high level by him self.
To achieve this the arduino is programmed in such a way that
- for a logical 0, it can bring D4 to ground (using an internal transistor)
- for a logical 1, it just put D4 in high impedance (so a floating voltage). Normally there should be a pullup resistor on Rx side that connect the Rx signal (= D4) to Vcc of the RX (3.3 V). It is this resistor that bring the voltage level to 3.3 volt when Arduino let it floating.

If the Rx has no pullup resistor, then the voltage is floating and communication will probably fail.
Adding just a pull up resistor between Arduino Vcc (5 v) and D4 is not safe for the Rx because when D4 is set in high impedance, the resistor wil bring the voltage to 5 v while the Rx is running at 3.3 volt.
So in order to reduce the voltage to 3.3 volt, you have to add a resistor to ground too. So you get a voltage divider that reduce the voltage from 5 volt to 3.3 volt when Arduino and Rx let it floating.

When Arduino and Rx do not want to force a level 0, they let their pin floating and it is the voltage divider that force the level to 3.3 volt
When Arduino want to force the level to 0, it drive the line to ground and it seeks the current from R 22k
When Rx want to to force the level to 0, it drive too the line to ground and it seeks the current from R 22k

Spitpt
Posts: 5
Joined: Thu Mar 23, 2017 8:44 pm
Country: -

Re: OpenXVario HOTT Support

Post by Spitpt » Sat Mar 25, 2017 3:08 pm

Hello,

In fact, it is necessary to put a pull up resistor 1.5 Ko between the Tx (pin 0) and Rx (pin 4) line of the Arduino, the Rx line stay dirctly wire to the T pin of the Data port of the receiver.

Now I have the indication on the transmitter that GPS and GAM modules were connected.

Thant you for the help.

Carbo
Posts: 241
Joined: Fri Aug 02, 2013 6:55 pm
Country: -

Re: OpenXVario HOTT Support

Post by Carbo » Sat Mar 25, 2017 3:59 pm

Spitpt wrote:
Sat Mar 25, 2017 3:08 pm
Hello,

In fact, it is necessary to put a pull up resistor 1.5 Ko between the Tx (pin 0) and Rx (pin 4) line of the Arduino, the Rx line stay dirctly wire to the T pin of the Data port of the receiver.

Now I have the indication on the transmitter that GPS and GAM modules were connected.

Thant you for the help.
Great that it works, but is it possible, that you mixed it up with connecting a flightcontroler to S-Port telemetry? Only there it is necessary to connect TX and RX simultaneously with a resistor (or diode, or diode+resistor). The better way imo is to use the circuit above, it works reliable with all kind of HOTT RX. I do not know, if your version can cause a malfunction, but imo it works only per 'accident'.

Have fun with your oXs!

Spitpt
Posts: 5
Joined: Thu Mar 23, 2017 8:44 pm
Country: -

Re: OpenXVario HOTT Support

Post by Spitpt » Sat Mar 25, 2017 6:46 pm

In my case, the power of the arduino come from the receiver (+ to RAW, - to GND, T to pin4 ant T+1.5 Ko resistor to pin0). This wiring work fine since a year on others home made modules (vario and voltage control).

Best regards

Post Reply

Return to “OpenXVario - an open source vario supported by the open source firmwares!!”

Who is online

Users browsing this forum: No registered users and 1 guest