[Wingnutt]

I have a revo evolution nano, and I have the OP GPS installed and everything works very well so far.

I really need to telemetry from the Nano, especially the GPS data (distance from home, direction from home)

I'm already using the flex port for the GPS, can I pull telemetry from any of the other ports?

[nitromethane]

Main port, then you run out of options on the Revo Nano.

I'm not 100% certain what you mean by "Revo Evolution Nano" tough...

[Wingnutt]

I'm using the main port for SBUS connection to my X8R Receiver...

But that leads to another question, I read my Taranis Plus can pull telemetry from the nano via the X8R.

I'm just not sure how.

[nitromethane]

If you're using MainPort for S.Bus and FlexiPort for GPS on a Nano, then you're out of serial ports for telemetry.

Other options you have are then are:
-> Use PPM or PWM to connect your receiver and run telemetry from Main or Flexi port
-> Get a full size Revo that has an additional serial port on the receiver connector that can be used for telemetry.

About the FrSky telemetry, yes it is possible to connect the Rx to read telemety from the Nano, but it would need to speak FrSky telemetry protocol which it currently doesn't (not implemented in firmware at this moment).
If I remember correctly there are or were some plans to implement that feature... eventually...

Edit: There is a task opened in the bug tracker and there seems to be some activity: https://librepilot.atlassian.net/browse/LP-117

[Mateusz]

About the FrSky telemetry, yes it is possible to connect the Rx to read telemety from the Nano, but it would need to speak FrSky telemetry protocol which it currently doesn't (not implemented in firmware at this moment).

• FrSky Telemetry is different from LibrePilot telemetry.
  
  • FrSky has signal inverted (would require external hardware inverter, or heavy for cpu software inverter)
  • FrSky telemetry uses their own SMART port protocol, which is completely different and way simpler than UAVTalk used by LibrePilot
  There is some work and discussion about it, but it's complicated hardware-wise. Best would be to have inverter which flight-controllers don't have.
  
• Revolution Nano has FlexIO port which should be the same as on Revolution. Check table in the following link https://librepilot.atlassian.net/wiki/display/LPDOC/Revolution+Configuration
  It should be possible to set FlexIO(receiver port) into mode in which two of pins serve as serial TX/RX for sending telemetry. That you can connect for instance to your OSD.

[nitromethane]

...

• Revolution Nano has FlexIO port which should be the same as on Revolution. Check table in the following link https://librepilot.atlassian.net/wiki/display/LPDOC/Revolution+Configuration
  It should be possible to set FlexIO(receiver port) into mode in which two of pins serve as serial TX/RX for sending telemetry. That you can connect for instance to your OSD.

Not true, none of the pins connected to the Nano's FlexIO port on the STM32F411 support hardware UART.

A simple external hardware signal inverter and voltage shifter isn't all that hard to make, but software UART sounds sweet

[Mateusz]

Not true, none of the pins connected to the Nano's FlexIO port on the STM32F411 support hardware UART.

I guess you are right. Easy to make such a mistake when you deal with closed-hardware such as Nano.
But to be honest I don't understand the idea behind buying small flight-controller which is striped down from features (less ports, no oplink, less beafy mcu) to save on weight/size, and than trying to connect GPS and lots of stuff to it. Isn't that a bit contradiction ?
If you have place and thrust to carry GPS and other components, why not to use full sized flight controller that as a bonus is open-hardware and you know exactly what sits inside ?

[nitromethane]

Back in the Republic of Dave (where war never changes) Nano was viewed as a replacement, which happens to have a beefy enough MCU to do autopilot stuff, for the aging hardware that is CC3D.

The die hard racing crowd wants to shave off every redundant gram of weight, so such hardware makes sense to them.

But then there are maniacs like me that first make a Nano case out of solid aluminium and then bolt the whole thing to a frame with arms milled out of 8mm aluminium plate and some 1,5mm plates in the center held together with a bunch of steel M3 screws, none less