Softserial not working with X4R SB on ßF > 3.1.5

[Wene001]

Hi

I´m using FPracing F3 Acro and a Frsky X4R SB on IO2 and Smartport connected to pin 6.
Using 3.1.5 and Smartport connected to softserial (IO2 Pin 5+6 bridged) all is working fine.
Using 3.1.6 or 3.1.7 and Smartport connected to softserial (IO2 Pin 6) Telemetry works sometimes for 2 Seconds . Sometimes telemetry comes up again.

Is this a bug?

Greetz Werner

[jflyper]

The new software serial has been around for months now. It's hard to imagine it still has a subtle bug with a popular FC like SPRF3.

I suspect you have wired the SmartPort wire to a wrong pin when you changed your wiring.

[Wene001]

Ive wired the smartport pin from X4R SB to IO2 Pin6 (softserial2 TX) on my FPRacing F3.
i tried to use Softserial 1 on IO1...also tried to remap Softserial2 TX to an other pin, using the resource command. Always with the same result.
After Board Reset the Telemetrie is working for a few seconds.
waiting one minute or so Smartport Telemetrie works for a few seconds again
Confused ?!?

In the ports tab i,ve enabled smartport for Softserial2
in the configuration tab i´ve enabled telemetry

EDIT:
Tested: Smartport Telemetry works fine on UART2 TXpin, but i would like to use UART2 for GPS

[daro6]

Hi Wene001,
as you can see in issue #2823, the softserial feature is disabled in 3.1.7 for the SPRACINGF3 target. The last working version is 3.1.5.
Greets,
Daniel

[Wene001]

Thanks
But in my case i could enable it and it works for a few seconds after Reset
Is there a chance that this feature is available in the next verions?

[mikeller]

@Wene001L SOFTSERIAL was removed from this target because it did not fit into the flash size. It should be added again in the next version.

[Wene001]

Thanks

[maciek01]

I have the same issue on a different target - BFF3:
s.port telemetry works during the startup for a few secs and then stops.

BFF3
BF 3.1.6
FRSKY everything else

connected via hardware UART3

I did not try <316

BTW - Unrelated to this issue: softserial seems to not work on BFF3 with 3.1.6 either (GPS is not found).

[mikeller]

@maciek01: GPS support was disabled for F3 boards in 3.1.6.

[monelli]

Same problem, telemetry works for a few seconds after Reset.
Solution:
set tlm_halfduplex = OFF
Tested on 3.2.0 on softserial with SPracingF3EVO and x8r.
SmartPort Telemetry.

[maciek01]

@monelli is your s.port cable attached to both TX and RX or just TX?

[monelli]

(>|) is a 1N4448 diode.

(RX)-----------------(SmartPort)
               /
(TX)---(>|)---/

[jflyper]

I think SmartPort for non-F3 target is broken in post-3.1.7, not only limited to softserial, but on all serial ports. #3190

[jflyper]

It's apparently working now (3.2.x)