Serial communication over Frsky Telemetry Link

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pekote
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Serial communication over Frsky Telemetry Link

Post by pekote » Fri May 29, 2015 2:02 pm

Having a look in Frsky products I found this set of converters. I was wondering if it can be used to send APM or any other FC telemetry data.

I also was wondering if It could also be used to connect APM to Frsky system and show APM data in Taranis radio.

"FrSKY S.Port To UART Converter (With 2 ADC Ports)"
https://www.hobbyking.com/hobbyking/sto ... duct=58202

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MikeB
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Re: Serial communication over Frsky Telemetry Link

Post by MikeB » Fri May 29, 2015 3:26 pm

Partly it depends on the quantity of data you want to send. The fastest these operate is 160 bytes/second in a single direction.
Alos, FrSky have not released the protocol they use for these over the SPort, so the only way of connecting them to the Tx is to use the SPort connection in the module bay and route the serial data to the serial port in the battery bay.

Then you need firmware to handle the serial data on that port.

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pekote
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Re: Serial communication over Frsky Telemetry Link

Post by pekote » Fri May 29, 2015 6:20 pm

I don't understand... from the manual it is specified that the baud rate can be "reconfiguration" to 300bps, 600bps.... 9600bps

but then below in is written "Mode 2-> Bidirectional Max 90bytes/sec" which is almost unusable for any application...

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MikeB
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Re: Serial communication over Frsky Telemetry Link

Post by MikeB » Fri May 29, 2015 7:05 pm

Yes, the SPort connection limits the maximum byte rate to this. You can get 140 to 160 in a single direction.

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Kilrah
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Re: Serial communication over Frsky Telemetry Link

Post by Kilrah » Fri May 29, 2015 7:27 pm

pekote wrote:that the baud rate can be "reconfiguration" to 300bps, 600bps.... 9600bps
That is the baud rate of the serial line between the adapter and whatever you're going to connect to it, it's configurable because the adapter must expect the same rate the other device sends with. It has nothing to do with how much data can be carried over the air in practice.


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jhsa
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Re: Serial communication over Frsky Telemetry Link

Post by jhsa » Fri May 29, 2015 7:36 pm

Hmm, isn't the baud rate the data transfer speed? How fast it can be transferred?

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Kilrah
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Re: Serial communication over Frsky Telemetry Link

Post by Kilrah » Fri May 29, 2015 7:41 pm

Yes but again that rate is only in effect between the adapter and the device that connects to it. The rate between the adapter and receiver is different, and the over the air rate is yet again different. All of these interfaces are independent.

pekote
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Re: Serial communication over Frsky Telemetry Link

Post by pekote » Fri May 29, 2015 8:16 pm

Thanks Kilrah,

Now I understand, the air link is pretty slow.

It is too slow that I would say that is almost obsolete for nowadays.

I think that the purpose of this module is mainly to provide 2 analog inputs, additionally it has some spare bandwidth and provide serial link for any other data...

Despite the module name is "FrSKY S.Port To UART Converter (With 2 ADC Ports)" I would rename the module to "2 ADC ports (with S.Port To UART Converter)"

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Kilrah
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Re: Serial communication over Frsky Telemetry Link

Post by Kilrah » Sat May 30, 2015 7:01 am

Well it's perfectly appropriate for what it's meant for, i.e. for transmitting down a few telemetry values or slow control/sync data. The main purpose of the link is still to transmit 16 channels of R/C fast and reliably, the downlink is an auxiliary "bonus" that will obviously not have the bandwidth a separate dedicate solution would.

The best solution would be to add smart port support to APM like in cleanflight where it works beautifully, so everything that is telemetry uses the existing lightweight standard instead of the heavy mavlink protocol and its overhead.

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Re: Serial communication over Frsky Telemetry Link

Post by rsilk49 » Sat Sep 17, 2022 9:09 pm

What is the communication speed of s.Port? Does it need to be configured on the Telemetry settings page (erskytx)?
I need to connect the s.Port on an XJT module to a Bluetooth module and I need to configure the connection speed of the serial port on the BT module.
S500 + Pixhawk 1 clone + Mauch PM + C&T Telemetry adapter + 9XR-Pro (Taranis gimbals)/XJT/X8R

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Kilrah
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Re: Serial communication over Frsky Telemetry Link

Post by Kilrah » Sat Sep 17, 2022 9:51 pm

57600. As mentioned in the reply to your other post the port on the module itself is entirely independent from the radio.

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Re: Serial communication over Frsky Telemetry Link

Post by rsilk49 » Sun Sep 18, 2022 5:46 pm

I have checked the HC-05 BT module connected directly (no radio) to a Matek F405 serial port, running Ardupilot and everything connects as expected with Qgroundcontrol on my Android phone, so that rules out problems with the BT module.

However, I cannot connect the BT module to the Telemetry viewer app running on the Android phone. This did work a year or so ago with same wiring, BT module, ersky9x s/w, XJT module.
I am sure the settings on the Model:Telemetry page are OK and the wiring for the XJT S.port <-> BT module has worked previously. Perhaps the inverter hardware between the XJT S.port and BT module has gone bad which seems unlikely. I do have a spare so may try to wire up another cable to verify it.

The other possibility is the Telemetry viewer app, which has been updated since I last tried this . . . .


ersky Telemetry settings:
BT Telemetry OFF
Telem. Com Port 1
Com Port Invert None
COM1 Baudrate AUTO
S500 + Pixhawk 1 clone + Mauch PM + C&T Telemetry adapter + 9XR-Pro (Taranis gimbals)/XJT/X8R


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