How many UDI users?

[OverTemp]

Wow... That's scary!

[OverTemp]

Well I ran it for 40 minutes today without a single error. Sweet. I guess I got the right settings!

Here are pics of the final setup.

[TeroS]

Originally Posted by Thunder Fighter

The issue I had with PPM was it kicking the ESC into soft start mode. If the throttle channel gets a single point at 0 the ESC (with the Vbar Governor) drops power and starts a soft start cycle. On other channels a single point out the data stream may not be noticeable as it gets corrected in the next frame and so the servo may not even have started to move.

UDI looks like it has solved the issue as any error in the frame should be disregarded. In practice this looks like it has worked for me, but I don't have enough flights on the model since the change to be 100% sure.

//Dennis.

What settings did You have on PPM? I can believe that behavior when time on 8ch PPM is something else than 20ms. The signals in scope were all over the place.

[Thunder Fighter]

Originally Posted by CP-Geek

What settings did You have on PPM? I can believe that behavior when time on 8ch PPM is something else than 20ms. The signals in scope were all over the place.

It was set the same as all of my other helis's running PPM, between 18 and 20ms and 8 ch. My Logo had this problem when I first switched to Jeti and I shortened the PPM lead and moved the wires, that fixed the problem for 100 or more flights, then it started re-occurring so I switched to UDI. I still need to get more flights on it to say conclusively that it has fixed it.

//Dennis.

[TeroS]

PPM 8 channels and 18 ms is going to be problematic (at least with VBar). I did a small write-up here: http://www.rc-thoughts.com/index.php...udi-with-vbar/.

I'm not sure how this corresponds to other gyro's, it all comes down to if they count channels or depend on blank detection-time which should be "normal" way with PPM.

Anyway, 18 ms with 8 channels gives only 2 ms to blank detection, and to my knowledge that's too little. (Anyone have exact data on this?)

[taosgraveyard]

Very true... There is another thread here on this forum somewhere about this.. For 8 channels I used 23 or 25 ms... Something like that

[TeroS]

cbdane did some testing with scope also, I also credited him (for a good reason) in my write-up.

I see no reason to use 23-25 ms, since all 8 channels @max = 8 x 2 ms = 16 ms and then add 4 ms for blank detection time. You'll just ad lag. (Alltho I think it's not noticeable in normal use.)

I'd love to get my hands on some other gyros and test them but I'm a VBar-dude

[Thunder Fighter]

If the Vbar was having trouble detecting the blank it would have shown up in the Vbar logs, but they were clean, so I am confident that wasn't the problem.

//Dennis.

[Vovets]

CP-Geek, what scope did you use while scoping UDI and PPM signals? Looking at pictures the scope's bandwidth leaves much to be desired...

BTW, I'm using UDI with VBars and recently Vortexes since it has been implemented in RX firmware without any trouble. I'm using 100Hz, auto, calculated output and programmed failsafe positions.

[cbdane]

Originally Posted by Vovets

CP-Geek, what scope did you use while scoping UDI and PPM signals? Looking at pictures the scope's bandwidth leaves much to be desired...

BTW, I'm using UDI with VBars and recently Vortexes since it has been implemented in RX firmware without any trouble. I'm using 100Hz, auto, calculated output and programmed failsafe positions.

His sampling rate doesn't support the UDI bit rate so you can't actually see the digital data stream. I think what he describes as "fuzz" is just aliasing due to the combination of low analog bandwidth and digital sampling rate.

[OverTemp]

No more errors with mine. No being in Auto was killing it.

[mkovalcson]

I'm still running 20ms 8 channels PPM on all my helis. So far I haven't had a hiccup or at least one that I'm aware of.

However I have done my best to make all my PPM leads very short and solitary so there is little nearby to affect them.

[Wizza]

Been a couple of months. Any updates guys..? Dennis, how are you getting on, and have you changed your settings.....?

Mark R

[ArguZ]

We are all waiting for Jeti to go S.Bus

[Wizza]

To someone who owns only Vbars, seems to be too much unknown here to consider Jeti and risk expensive Helis......... Keen to hear some further feedback and experiences from the past couple of months....

[Only Fine Helis]

I am currently running 4 Helis with UDI and MSH brains with no issues.

I am testing S bus currently with no issues on another Heli. Can someone with a technical background explain to me the benefit of S bus over UDI?

Thx!

[Wizza]

Maybe sbus is the magic answer. It's still in beta isn't it..?

[Vovets]

Actually in my opinion UDI is slightly more robust. Both of them transmit data in packets. But UDI calculates checksum over whole packet while sbus uses one parity bit per byte.In the case of strong interference UDI's probability of detecting broken packet is higher. They both transmit about 100000 bits/s. UDI transmits 12 channels with 4096 points resolution, sbus - 16 channels with 2048 points resolution.

[Only Fine Helis]

Do both have the same potential for interference?

[Only Fine Helis]

To follow up on my question -

What I'm wondering is where the issue may be because I've used futaba S bus for years with not even a hint if an issue. So if UDI is potentially stronger then where is the problem coming from in certain people's setups?