PPM Frame size

Hardware Support for the 9XR
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afon
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PPM Frame size

Post by afon » Thu Aug 27, 2015 5:40 pm

Hi All,

I have Turnigy 9XR + FrSky DJT + FrSky D4R-II

D4R-II was flashed with 27ms firmware because I want to use 7 channels.

My question is: what PPM frames size should be set in TX settings (openTx or er9x)?

At this moment in my TX settings I have (by default) PPM Frame 22.5ms 300u Negative

Is it OK?

I am not sure, that it is OK because D4R-II waiting for frames with 27ms size.
Last edited by afon on Thu Aug 27, 2015 8:24 pm, edited 1 time in total.


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MikeB
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Re: PPM Frame size

Post by MikeB » Thu Aug 27, 2015 7:16 pm

How many channels are you sending, 8 I would guess since you want 7, and you have to choose either 6 or 8.
I would suggest allowing 2.1mS per channel and at least 4.5mS for the sync time so, for 8 channels, that is 8*2.1 + 4.5 = 16.8 + 4.5 = 21.3.
21.5 is the minimum to use so the default of 22.5 is fine.
The D4R generates the output CPPM using 27 mS, but this is independant of the rate sent from the Tx to the DJT.
So, 22.5mS is perfectly OK.

Mike.
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afon
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Re: PPM Frame size

Post by afon » Thu Aug 27, 2015 8:26 pm

Hi Mike.

Thank you very much. Your answer really helped me to understand underlying settings.

I will leave PPM Frame size "as is" (22.5ms)

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Buzzliteyear
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Re: PPM Frame size

Post by Buzzliteyear » Wed Mar 04, 2020 7:10 am

Hi Mike ,
can i use the same formula for 12 channels Sbus LRS and ER9x on turnigy 9x 12 x 2.1 + 4.5 = 29.7 + 4.5 = 34.2ms ?

no option above 32.5ms in my FW version

Brett

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Kilrah
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Re: PPM Frame size

Post by Kilrah » Wed Mar 04, 2020 7:42 am

What module?


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Buzzliteyear
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Re: PPM Frame size

Post by Buzzliteyear » Wed Mar 04, 2020 9:29 am

Ebyte Lora module 433,
I just manager to hook it up and try and it wont work on selecting Sbus
is there Sbus output from turnigy 9x with er9x firmware?

Brett

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Kilrah
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Re: PPM Frame size

Post by Kilrah » Wed Mar 04, 2020 9:34 am

If you output SBUS then PPM timings have nothing to do with it...

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Buzzliteyear
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Re: PPM Frame size

Post by Buzzliteyear » Wed Mar 04, 2020 10:04 am

Ofcoarse .....i see now.....

i dont understand the sbus output, If i move the throttle it is like the gap in the first pulse increases
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Last edited by Buzzliteyear on Wed Mar 04, 2020 12:16 pm, edited 1 time in total.

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MikeB
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Re: PPM Frame size

Post by MikeB » Wed Mar 04, 2020 10:42 am

er9x does support SBUS, however this is "standard SBUS" currently that is inverted, logic 1 = 0V, logic 0 = positive voltage.
SBUS is sent at 100000 baud. Your logic capture is sampling at 20kHz (20000) so is not fast enough. To capture 100000 baud, you need to sample at least twice as fast as 100kHz, I would use a sample rate of 1mHz.
Does your module accept the inverted signal?

I make the PPM calculation:
12 x 2.1 + 4.5 = 25.2 + 4.5 = 29.7ms ?

Mike
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Buzzliteyear
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Re: PPM Frame size

Post by Buzzliteyear » Wed Mar 04, 2020 12:37 pm

No it does not accept inverted signal I made this inverter with BC547,
I did another sample @ 1mhz after the inverter and got about 66 frames (only about 15 shown in pic below)... does that seem normal ?
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MikeB
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Re: PPM Frame size

Post by MikeB » Wed Mar 04, 2020 7:09 pm

Your SBUS signal is not correct. You should see about 9 frames per second (1 every 11 mS), and the waveform should be a standard UART at 100000 baud, 12 bits per character, 1 start, 8 data, 1 even parity and 2 stop.
Try checking the signal from the radio, on the 9X, this is at 5V.
You might also check your connections to the BC547.

Mike
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MikeB
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Re: PPM Frame size

Post by MikeB » Wed Mar 04, 2020 10:24 pm

I've just posted a test version of er9x that includes a polarity option for the SBUS protocol output.

Mike
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Buzzliteyear
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Re: PPM Frame size

Post by Buzzliteyear » Thu Mar 05, 2020 6:09 am

Ok it is working

not sure why but this is the hookup

9x signal is inverted going through inverter = non inverted signal to Tx Lora module

Rx side = Rx Lora module feeds inverted uart 6 PPM/Sbus pin only ( not uart 1,3 or 6 on the left side on the omnibus F4 v3)

thanks heaps for the help Mike

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Buzzliteyear
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Re: PPM Frame size

Post by Buzzliteyear » Thu Mar 05, 2020 7:16 am

822c ? I just flashed that cant see polarity option............

https://openrcforums.com/forum/viewtopi ... 598#p64969

Perfect Works Great thanks again........dont need that invertor now.......where the donate button :)

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MikeB
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Re: PPM Frame size

Post by MikeB » Thu Mar 05, 2020 10:10 am

There is one on here: https://github.com/MikeBland/mbtx, or "jhsa" has a link at the bottom of his posts.

Mike
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Buzzliteyear
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Re: PPM Frame size

Post by Buzzliteyear » Fri Mar 06, 2020 2:43 am

Done cheers.......Brett

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Re: PPM Frame size

Post by axljackass » Sun Jan 03, 2021 2:32 pm

MikeB wrote:
Wed Mar 04, 2020 10:24 pm
I've just posted a test version of er9x that includes a polarity option for the SBUS protocol output.

Mike
hi Mike,

Possible to include this to M64 9X?
Want to test this to my 9X with LORA module but i have M64.
Thanks.

Axl

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MikeB
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Re: PPM Frame size

Post by MikeB » Sun Jan 03, 2021 3:35 pm

It should be there already. I've posted a new test version earlier today, so if you do not have the option, please try this test version.

Mike
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axljackass
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Re: PPM Frame size

Post by axljackass » Sun Jan 03, 2021 11:36 pm

MikeB wrote:
Sun Jan 03, 2021 3:35 pm
It should be there already. I've posted a new test version earlier today, so if you do not have the option, please try this test version.

Mike
Hi Mike,

i supposed is this firmware.
er9xProv822w.zip
03-Jan-2021 11:31
Fix (possibly!) PC4(L-WR) not working as extra digital input
(1.07 MiB) Downloaded 2 times

can i check with you if the M'Sound serial also included inside this firmware.

Thank you for your support.

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MikeB
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Re: PPM Frame size

Post by MikeB » Mon Jan 04, 2021 11:30 am

Yes MegaSound serial is included (er9x-frsky-sv.hex).

Mike
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axljackass
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Re: PPM Frame size

Post by axljackass » Mon Jan 04, 2021 10:18 pm

MikeB wrote:
Mon Jan 04, 2021 11:30 am
Yes MegaSound serial is included (er9x-frsky-sv.hex).

Mike
Hi Mike,

Telemetry for s.port still need to use inverter or already converterted in the new firmware?
Thanks

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MikeB
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Re: PPM Frame size

Post by MikeB » Wed Jan 06, 2021 9:46 pm

No, you will still need an inverter for the SPort telemetry. On the AVR processor, it is not really possible to invert this in firmware.

Mike
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axljackass
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Re: PPM Frame size

Post by axljackass » Thu Jan 07, 2021 7:00 am

MikeB wrote:
Wed Jan 06, 2021 9:46 pm
No, you will still need an inverter for the SPort telemetry. On the AVR processor, it is not really possible to invert this in firmware.

Mike
Noted.
Thanks.

(",

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Re: PPM Frame size

Post by axljackass » Fri Jan 08, 2021 4:12 am

Hi Mike,

Just want to report something.

While im waiting for my 0ohms smd resistors, to be use for arduvoice voice mod, i decided to return back to non mod firmware for my M64 turnigy 9x radio.
I downloaded the M64 Frsky and Standard versions from ER9X website but after i flashed i noticed no beep sound after flashing, something was not right.
Then i compiled for my M64 and after flashing there was a beep sound.
Also the Test Version have beep sound after flashing.

Edit: disregard the my post, found to be beeper was off


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