wcfung

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Wiring Revo (running Arducopter) for telemetry
« on: July 23, 2020, 01:59:41 am »
Hi,

My Revo (full size) is flashed with Arudcopter FW. The Main port and Flexi port are already connected to OSD and GPS respectively. I now want to connect a Sik radio to FlexiIO for telemetry by following the Revo configuration in LiberPilot documentation as follows:--

Vcc and Grd of Revo to Vcc and Grd of Sik radio
Tx (yellow wire) of Revo to Rx of Sik radio.
Rx (green wire) of Revo to Tx of Sik radio.

After power up, the green LED of both radio is solid (instead of blinking), meaning link between the pair is established.
But the red LED is not flashing, meaning no data is transmitting.

The pair of Sik radio is proved to be working in another set up.

Questions :--
1) What has gone wrong that there is no data transmitting ? Do I have to do some configuration in LibrePilot which may be quite troublesome as I have to delete the Arducopter FW and go back to LibrePilot ? 

2) Assuning I am successful to have data transmitted, the yellow wire from Revo is normally connected to receiver  for PPM, how can I use the yellow wire for telemetry at the same time ?

Appreciate your help.

karla

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Re: Wiring Revo (running Arducopter) for telemetry
« Reply #1 on: July 23, 2020, 05:06:40 am »
Hi, I think whatever changes you would do using LibrePilot FM, that will all be gone ones you flash it again with Arducopter FM. I don't think you can do telemetry and ppm the way you suggest. However do you have the rfd900x unit Sik radio that can do rc ppm and telemetry at the same time, then you could possibly set it up a little differently. Sik unit ppm wire to FlexiIO port and the tx/rx wires to the main port (used for OSD now). I think you could then use the tx pin in parallel to output data to your OSD.
I have not tested it but could work.
You might get more relevant answers over at Ardupilot forums :)

wcfung

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Re: Wiring Revo (running Arducopter) for telemetry
« Reply #2 on: July 23, 2020, 07:10:07 am »
Karla,
Thanks for your reply. I do not have RFD900. My question #2 was discussed. However, for question #1, I am still puzzled.

Two points we need to focus :--
a) When I test the Sik radio by connecting 4 wires (Vcc, GRD, yellow, and green) from Revo FlexiIO port  to Sik radio, no receiver was connected to Revo, thus the yellow wire is ONLY used for telemetry, not for PPM, there was still NO data transmission.
b) When the Sik radio is connected to the Main Port of Revo, it works perfect (even though the Revo is already flashed with Arducopter firmware) and I have been doing this for many times in 3 different Revo.

So I am curious why it did not work when the yellow wire is not used in PPM, only in telemetry.

Thanks

Re: Wiring Revo (running Arducopter) for telemetry
« Reply #3 on: July 23, 2020, 08:23:03 am »
It is like you have gone to the Toyota car forum to ask how to pair your phone with a Honda car.  We don't have Honda cars here and don't know their quirks or how to configure them.  :)

Sorry...

Edit after Karla response:
I was going to add that you are welcome to ask here but probably won't get an answer, but then I thought that I am not going to make a decision about that by myself, and we could possibly get a lot of non-LibrePilot questions and I would have to take it back, so I erased the additional statement.  Hope I didn't come across as mean...  :)
« Last Edit: July 23, 2020, 07:58:38 pm by TheOtherCliff »

karla

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Re: Wiring Revo (running Arducopter) for telemetry
« Reply #4 on: July 23, 2020, 10:53:03 am »
wcfung, although cliff is absolutely right, I would try to give you my best advice based on experience, that's not much but still.

Your Q1 about changing something with LibrePilot FM and then hope to benefit from it using Ardu - forget it, it's a dream. You need to focus what can be done with the Ardu definition of the Revo hardware, its all you have when using Ardu.

You seem to have an assumption that data is just data: like telemetry data is the same as radio ppm data.
Well its not. I am really not an expert, but because of that I can understand your thinking - what could possibly the problem :)

Still, you have options to get things to work.
Why not use the main port for telemetry, since you say it works fine, and copy it out to your OSD?

wcfung

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Re: Wiring Revo (running Arducopter) for telemetry
« Reply #5 on: October 23, 2020, 05:11:31 am »
It is like you have gone to the Toyota car forum to ask how to pair your phone with a Honda car.  We don't have Honda cars here and don't know their quirks or how to configure them.  :)

Sorry...

Edit after Karla response:
I was going to add that you are welcome to ask here but probably won't get an answer, but then I thought that I am not going to make a decision about that by myself, and we could possibly get a lot of non-LibrePilot questions and I would have to take it back, so I erased the additional statement.  Hope I didn't come across as mean...  :)

I was a bit puzzled initially when posting because my question involves both hardware and firmware. And I have no  background on software/firmware, so don't know where I should post.

wcfung

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Re: Wiring Revo (running Arducopter) for telemetry
« Reply #6 on: October 23, 2020, 05:15:58 am »
wcfung, although cliff is absolutely right, I would try to give you my best advice based on experience, that's not much but still.

Your Q1 about changing something with LibrePilot FM and then hope to benefit from it using Ardu - forget it, it's a dream. You need to focus what can be done with the Ardu definition of the Revo hardware, its all you have when using Ardu.

You seem to have an assumption that data is just data: like telemetry data is the same as radio ppm data.
Well its not. I am really not an expert, but because of that I can understand your thinking - what could possibly the problem :)

Still, you have options to get things to work.
Why not use the main port for telemetry, since you say it works fine, and copy it out to your OSD?


Hi Karla,
I made a mistake, I don't haveRFD900, not even RFD900X. I only have Sik radio. 

Yes, I can use the main port for telemetry as usual, but I don't understand how to "copy it out to OSD". Please elaborate. Thanks

karla

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Re: Wiring Revo (running Arducopter) for telemetry
« Reply #7 on: October 24, 2020, 03:06:22 am »
Hi wcfung,

Quote
Yes, I can use the main port for telemetry as usual, but I don't understand how to "copy it out to OSD". Please elaborate. Thanks

The main port has a TX and RX pin, solder a parallell wire to the TX wire and connect it to the RX pin of your OSD unit. Thats all. It will not give you the full functionality of the OSD but you will have a lot of data displayed. Try it?

wcfung

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Re: Wiring Revo (running Arducopter) for telemetry
« Reply #8 on: October 30, 2020, 10:41:33 pm »
Hi Karla,

I solder a wire to the Tx of main port of Revo and connect it to the Rx of OSD. After powering up, both telemetry and OSD work, and no data is missing from OSD, ie. no function is lost. Thank you for your help.

While on the topic of Revo connection, I have more queries :-- I normally connect GPS module to flexi port of Revo, and OSD or (now and) telemetry radio to main port. This works without problem.
Now I try following :--
1) Swap the GPS to Flexi port, no GPS fix, even after a long time. If it is waiting for 3D fix, HDOP will show 100 instead of 0. But wiki clearly says Flexi port also supports GPS. Appreciate your help.
2) Swap the OSD (only) to Main port, it works. But when I add the telemetry radio by soldering a wire as above, telemetry does not work. OSD is not affected after adding the telemetry to Main port. Any clue ?

Thank you.

 

karla

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Re: Wiring Revo (running Arducopter) for telemetry
« Reply #9 on: October 31, 2020, 05:43:30 am »
Glad it works.

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After powering up, both telemetry and OSD work, and no data is missing from OSD, ie. no function is lost.

Can you change the bat voltage, capacity and swop to different OSD screens as well?
I vaguely remember I did not get that to work properly with just the tx cable connected.
Maybe that's done via PPM radio input though...

Swapping GPS and Telemetry between Main and Flexi ports should work just fine.
Check you set the correct gps protocol and speeds are correct for gps and telemetry. Also remember to power the gps unit with a battery. In some rare case I remember a Revo with a flexi port (or main, cant remember) where telemetry stopped working. Some hardware problem, but that was the only case for years.