openlrs and taranis (telemetry)

[aadamson]

So for the guys that know (or gals)...

openlrs supports the frsky protocol. In the TX flavor of openlrs, it's a JR type module that will plug into the taranis and work just fine, just with no telemetry.

Telemetry (RSSI) works on the turnigy versions of transmitters and as best as I can tell the 5 pin connector pinout of the openlrs tx module is as follows.

1 - ppm
2 - rxd
3 - raw (must be voltage from the tx)
4 - gnd
5 - txd

The schematic that I looked at doesn't *invert* the serial stream as best as I can tell, at least there is no hardware in the module to do that... So maybe that is needed..

I'm just curious if there would be any way to get telemetry (RSSI) functional between openlrs and opentx (taranis flavor)??

Anyone know or have the magic sauce?

Alan

[MikeB]

Many have modified their FrSky DJT to use the same pinout, with the telemetry Tx and Rx on pins 2 and 5 (TX on pin 5 is data From the module).
This signal is at RS232 levels (inverted therefore), and the 9X is modified with a buffer-invertor to allow for this.
The Taranis Sport signal, also on pin 5, is also inverted.
There is no obvious way of making the Taranis invert this signal.

Mike.

[aadamson]

Many have modified their FrSky DJT to use the same pinout, with the telemetry Tx and Rx on pins 2 and 5 (TX on pin 5 is data From the module).
This signal is at RS232 levels (inverted therefore), and the 9X is modified with a buffer-invertor to allow for this.
The Taranis Sport signal, also on pin 5, is also inverted.
There is no obvious way of making the Taranis invert this signal.

Mike.

Thanks Mike, let me digest what you said and I'm sure i'll have a few more questions!

Alan

[aadamson]

Many have modified their FrSky DJT to use the same pinout, with the telemetry Tx and Rx on pins 2 and 5 (TX on pin 5 is data From the module).
This signal is at RS232 levels (inverted therefore), and the 9X is modified with a buffer-invertor to allow for this.
The Taranis Sport signal, also on pin 5, is also inverted.
There is no obvious way of making the Taranis invert this signal.

Mike.

Thanks Mike, let me digest what you said and I'm sure i'll have a few more questions!

Alan

[kha]

Many have modified their FrSky DJT to use the same pinout, with the telemetry Tx and Rx on pins 2 and 5 (TX on pin 5 is data From the module).
This signal is at RS232 levels (inverted therefore), and the 9X is modified with a buffer-invertor to allow for this.
The Taranis Sport signal, also on pin 5, is also inverted.
There is no obvious way of making the Taranis invert this signal.

Mike.

So, it would be rather easy to make openLRS module output inverted signal, I can design a XOR port inside so that the signal can be inverted by software when needed.

We are anyway workking on a new TX module version with better RF output stage to get rid of stupid limitations of the RFMxx modules.

[MikeB]

That would be good. In passing, the 9XR PRO has a programmable invertor on the serial input from pin 5.

Mike.

[Rob Thomson]

Maybe this thread should be moved to the OpenLRS Section?

[aadamson]

Maybe this thread should be moved to the OpenLRS Section?

I didn't know where to start it, openlrs section seemed to be specific to that hardware and this is specific to the openlrs module in the taranis radio... the hardware works everywhere else...

[ChristianGeek]

I'm only measuring 2.3V between voltage and ground...does that seem right?

[kha]

I'm only measuring 2.3V between voltage and ground...does that seem right?

Taranis has switched power on the module bay. You must have external module enabled (ppm) to have power there.

It should be noted that module connection on taranis is

(ppm) (??) (vin) (gnd) (smartPort)

Next version of openLRSng will support smartPort telemetry for taranis (with invertter added to the module).

There seems to be some signal on the second pin but I don't know its function.

Sent by kha's fat fingers on phablet

[Kilrah]

2nd pin was planned for the module to be able to signal the radio when it is best to send it new data to optimize latency. This functionality isn't present in the current XJT firmware, and thus not used in openTx either. But it would be clever to use it, if you want to add circuitry for it an open collector will do (it's a transistor buffer with pullup and a diode on the input - i.e. pulling the pin low will make the signal active).

[ChristianGeek]

I'm only measuring 2.3V between voltage and ground...does that seem right?

Taranis has switched power on the module bay. You must have external module enabled (ppm) to have power there.

It should be noted that module connection on taranis is

(ppm) (??) (vin) (gnd) (smartPort)

External module enabled, 2.3V between pins 3 and 4.


Sent from my iPhone using Tapatalk

[kha]

I'm only measuring 2.3V between voltage and ground...does that seem right?

Taranis has switched power on the module bay. You must have external module enabled (ppm) to have power there.

It should be noted that module connection on taranis is

(ppm) (??) (vin) (gnd) (smartPort)

External module enabled, 2.3V between pins 3 and 4.


Sent from my iPhone using Tapatalk

That's not good. Are you countting the pins starting from top (nearest to antenna). Maybe you have accidentally shorted them and destroyed the FET driving it.?

Sent by kha's fat fingers on phablet

[ChristianGeek]

Yes, counting down from the top. I don't think I could have shorted them...the test leads I'm using make it virtually impossible.

Voltage measured is slowly dropping in proportion to main.

EDIT: Sorry, I was counting from the bottom. 3 and 4 are 0V, 2 and 3 were 2.3V. Assuming that I did somehow fry the FET, what are my options?

[obor]

So, it would be rather easy to make openLRS module output inverted signal, I can design a XOR port inside so that the signal can be inverted by software when needed.

hi,
I have signal inverters like this: http://www.flashrc.com/flyboard/10697-s ... 8_sup.html
I will soon receive the flytron module, I can test openLRSng telemetry within Taranis.
Do you know what "smartport" really means ?

[kha]

So, it would be rather easy to make openLRS module output inverted signal, I can design a XOR port inside so that the signal can be inverted by software when needed.

hi,
I have signal inverters like this: http://www.flashrc.com/flyboard/10697-s ... 8_sup.html
I will soon receive the flytron module, I can test openLRSng telemetry within Taranis.
Do you know what "smartport" really means ?

Yes that should work when connected right.

I have pretty good idea on smartport operation and I have it already implemented for rssi and analogs. Support for frsky/smartport sensors on receiver will follow later. (yes I will support conversion from old frsky to smartport)

Sent by kha's fat fingers on phablet

[kha]

I have pretty good idea on smartport operation...

Oh and while marketed as fullduplex in reality it is halfduplex without proper collission detection.

Sent by kha's fat fingers on phablet

[obor]

I have pretty good idea on smartport operation and I have it already implemented for rssi and analogs.

Great!
Where can i get it ?

[ChristianGeek]

EDIT: Sorry, I was counting from the bottom. 3 and 4 are 0V, 2 and 3 were 2.3V. Assuming that I did somehow fry the FET, what are my options?

Anyone?

[obor]

Hi,
I received today the Flyrtron openlrs Futaba module , and an adaptor board for JR module
The module adapter has a PPM inverser already included, but I don't see any pin external on the module for com port tx/rx.

Inside the module, however there is tx/rx on some other pads.

If there is one pin left on the module connector, I will try to connect the tx or rx there and then wire also to the Rx input of the taranis.

Any hint ?

[kha]

Taranis smartport is on the pin marked ant on the adapter. You need to connect the serial tx onto that via a invertter to make it work.

As openlrsng does not need the ppm invertter you could reuse that

Sent by kha's fat fingers on phablet

[kha]

Updated some openLRSng + Taranis info here https://github.com/openLRSng/openLRSng/ ... etry-guide

Sent by kha's fat fingers on phablet

[obor]

Now I have the telemetry which works with my Taranis, thanks for your help !
I had to adapt my signal inverter, especially to replace the 10k resssitor on TX input, as the IO levels were too low otherwise.
The Flytron V3/1w is installed in the JR module plastic box (sold also by Flytron), I had to clip a bit the plastic box on the side.
I discover also that Analog 0 &1 are located on the SDA/SCL pins. It will need a voltage divider also to measure the prop battery voltage.

One thing I saw during my test, is jitter on servos connected to receiver.

It could be nice to control transmit power of the Tx module with one pot of the radio.

[Kilrah]

I have an 1W Orange on my way, will see how it works