Cleanflight SmartPort Telemetry without Hack

[quadfather]

It';s often said that you need an inverter to use SmartPort.  This is correct, if you';re using hardware serial ports on F1 targets, like the Naze32, but it';s possible to use SmartPort telemetry without hacking or additional inverters.

The solution is Softserial, however, as you may or may not know, this also has drawbacks.  Increased load on the CPU, programmable LEDs, current metering or Sonar are disabled, and only 19200 baud across all Softserial ports.

So, it';s not a perfect solution, but if you';re willing to use Softserial here';s how to do it without hacks or inverters.  I';m using the X4R-SB in CPPM mode and a Naze32 for this example.  In theory this should work with any FC that can use Softserial, e.g. Flip32, CC3D, etc.


What I used

• X4R-SB with CPPM firmware.  See here: http://www.multi-rotor.co.uk/index.php?topic=14749.0
• Naze32 with Cleanflight 1.10.  Any firmware version that supports SmartPort should work.
• Custom cable for SmartPort.  See below.

Custom Cable

This is the "secret" ingredient!  Use the four-wire PicoBlade cable that came with the X4R to make a Y-splitter for the SmartPort signal pin.  Simply bridge two pins in a servo-type plug and connect one of them to the PicoBlade wire.  The result looks like this:




Configure Cleanflight

• In the Configuration tab select
  
  • RX_PPM
  • TELEMETRY
  • SOFTSERIAL
  Click Save and Reboot
• In the Ports tab select SmartPort telemetry for one of the two Softserial ports.  Click Save and Reboot
• In the CLI tab type
  
  • set telemetry_inversion = 1
  • save

Connect the RX

• Disconnect the Naze from USB and/or battery.
• Connect the RX to the receiver port in the usual manner.
• Plug in your Y-splitter telemetry cable.
  
  • For Softserial1 plug it into pins labelled 5 & 6.
  • For Softserial2 plug it into pins labelled 7 & 8.
• Power it all up

You should now have telemetry on your radio.



NB: In the above picture VFAS shows 0 because I didn';t have the VBAT pins connected.  Otherwise you would see the LiPo voltage there.

Hope it helps.

[Soler]

Why do you need the special cable,  I did this with connecting to the tx pin of the soft serial to the smart port RX

[quadfather]

It shouldn';t work, and it didn';t work for me with just the TX pin connected.  SmartPort is a bidirectional half-duplex protocol over a single wire.  The receiver sends a request for SmartPort data to the FC, which is why you should need the TX pin connected as well.

[Soler]

My mistake,   I was considering the D4R-II  which is D telemetry not X or Smart Port.   With the D4R-II I set it up in the same way but with just 1 wire.

[Cheredanine]

additionally smartport has a minimum baud rate of 56K I think (may be higher, certainly not lower)
Soft serial as a max baud rate of 19K, cant run smartport off softserial

[AtomicBomberman]

It';s working! The cable did the trick - but is it a good solution to shorten RX and TX?

Btw: i';m using Naze32 Rev6 and a X8R receiver

the receiver is connected with SBUS so i don';t need to set RX_PPM

[Fletch]

I MAY have inverters next week ... if I can make them work ... the will be this size

[Cheredanine]

It';s working! The cable did the trick - but is it a good solution to shorten RX and TX?

Btw: i';m using Naze32 Rev6 and a X8R receiver

the receiver is connected with SBUS so i don';t need to set RX_PPM

It isn';t a problem that would harm the board, the Naze talks out of one pin and listens to another, there is the possibility that it basically rebroadcasts its self but I think this is ok as it would use the same device id (internal to smartport signal details) so don';t think it concatenates. Main worry is the baud rate and is it reliable

[freesky.]

I MAY have inverters next week ... if I can make them work ... the will be this size

That sounds awesome. Can you give us a clue as to how you plan do do this? I';m interested in the circuits for this stuff!
Will defo buy from you if you pull it off.
Thanks, Dan

[Fletch]

i don';t think its going to work.....
Cleanflight puts the smartport stuff out on one channel, this mod needs it on TX and RX pins ... I';ll experiment and see what happens ... if i get it to work I';ll post up!

[Fletch]

Just waiting for the little SMD dual inverter ....

[quadfather]

i don';t think its going to work.....
Cleanflight puts the smartport stuff out on one channel, this mod needs it on TX and RX pins ... I';ll experiment and see what happens ... if i get it to work I';ll post up!

Cleanflight uses RX and TX for SmartPort.  Which inverter are you going to put on it?

[Fletch]

I';ve ordered this

SMD SMT PCB Dual Inverter Gate CMOS SOT-23-6 32mA 5.5V 5.5ns SN74LVC2GU04DBVR

[Fletch]

Quick test earlier and I couldn';t make it work.

It was my first attempt at soldering an SMD.  I have a few so I will try again and see how I get on.

Tried a few different combinations of wires and settings

[wangel]

Ok, pardon my newbness, but I found this thread doing a google search for Naze32 rev6 and X4R.

Right now, all my stuff is Spektrum... I bought a Taranis for my xmas present    I';m in the process of switching it all out.

1 of my quads is a Naze32 Rev5, has osd, etc, so I';m not too concerned about telemetry.

My tweaker, is a Naze32 Rev6, no osd.  I Really want telemetry.   I also, have programmable LED';s on my tweaker (just 1 strip).   If I try to use the X4R, then my led';s "wont" work? 

I';m debating.  LEDS or get a D4R-II for the tweaker.   That';s what I don';t understand? 

Also, how much increase load is on the CPU if I use Softserial for the telemetry?  Also, I guess I can';t use SBUS + Telemetry with the Naze32?

Thanks!
~wangel

[quadfather]

The Naze is rather limited in terms of connectivity.  An additional problem is that FrSky X-range receivers want inverted signals for both control and telemetry.  The rev6 has partially solved this by adding an inverter so you can use SBUS directly, however telemetry is still a no go.  There are inverters and RX hacks to "un-invert" the signals, but it';s still not a proper solution.

You always have to compromise with the X4R and a Naze (rev5 or rev6).  You can';t use SBUS or SmartPort on UART1.  If you use SmartPort on UART2 you can';t use SBUS and vice versa.  If you use softserial you can';t use programmable LEDs.  If you then want an OSD (or other serial device) it complicates things even further.

If you were to use the D4R-II on your Tweaker you could get telemetry and programmable LEDs, but you wouldn';t have the precision of SBUS.  The latter may not be relevant to you (yet), depending on your skill level.

I don';t know how much softserial weighs on the CPU.  I have read that you can';t lower the loop times as much, but I couldn';t tell you how big the difference is.

[Cheredanine]

The Naze is rather limited in terms of connectivity.  An additional problem is that FrSky X-range receivers want inverted signals for both control and telemetry.  The rev6 has partially solved this by adding an inverter so you can use SBUS directly, however telemetry is still a no go.  There are inverters and RX hacks to "un-invert" the signals, but it';s still not a proper solution.

You always have to compromise with the X4R and a Naze (rev5 or rev6).  You can';t use SBUS or SmartPort on UART1.  If you use SmartPort on UART2 you can';t use SBUS and vice versa.  If you use softserial you can';t use programmable LEDs.  If you then want an OSD (or other serial device) it complicates things even further.

If you were to use the D4R-II on your Tweaker you could get telemetry and programmable LEDs, but you wouldn';t have the precision of SBUS.  The latter may not be relevant to you (yet), depending on your skill level.

I don';t know how much softserial weighs on the CPU.  I have read that you can';t lower the loop times as much, but I couldn';t tell you how big the difference is.

Hi mate, a little confused, LEDs take out soft serial 1 because they eat pin 5 but ss2 should still be available for telemetry (although load on proc remains a problem)

[quadfather]

Hi mate, a little confused, LEDs take out soft serial 1 because they eat pin 5 but ss2 should still be available for telemetry (although load on proc remains a problem)

To the best of my knowledge you can';t enable the LED strip feature when softserial is enabled.  The pins may be free but the functionality isn';t there.

[zazza123]

It';s working! The cable did the trick - but is it a good solution to shorten RX and TX?

Btw: i';m using Naze32 Rev6 and a X8R receiver

the receiver is connected with SBUS so i don';t need to set RX_PPM

AtomicBomberman could you please send me some photos oh how you hooked up the x8r to the naze32 rev 6 i have the same setup and im struggling to go the telemetry going. An a screen grab of your Cleanflight ports page.

Thanks heaps

[gb0wers]

QF, I followed the method described in this thread and got my Naze32 sensor data to my Taranis via S.Port and softserial.

Is there any way I can daisychain in a FrSky S.Port current sensor as well please?

Thanks

Graham

[AmiSMB]

With Smart port you can just connect each smart port sensor one after another. I have connected the flight controller to the GPS and the current sensor and back to the receiver without any issues. My FrSky Smart Port is running via softserial 2 on a SP F3 Deluxe.