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Old Apr 15, 2014, 05:55 PM
Xtreme Power Systems
Lake Havasu, AZ
Joined Jun 2005
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Long frames issue

There is a problem using any transmitter where it's PPM output to our module exceeds a frame rate >30ms.

Since the XtremeLink system was never designed to handle frames this long, it doesn't. The EVO, XPS3216, DX18, etc. all can output 16 or more channels with no issues because they use fast frame rates (well under 30ms).

Right now, it's just the Taranis that shows this issue. The problem is actually on the receiver side, not the transmitter side. The solution is a firmware upgrade for the Nano II, RFU, and X10+ to be able to deal with the long frame rates. I am working on this right now.

The Nano II will be updated to have the same servo output functionality as the X10+, making the servo outputs now port based instead of channel based. This means that reversing and offsets will be for each individual port, not channel. I also added telemetry output for the Nano II receiver - but it is limited strictly to RSSI (LQI) data since the Nano II has no ability to measure battery voltage. You do have to enable the telemetry mode and refresh rate using the XDP or Telemetry Station. There is no other way to do it.

I do not know if the original Nano has sufficient code space to get the upgrades, I will be looking into that.
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Old Apr 15, 2014, 06:23 PM
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Do I understand correctly; this is a non/issue with the "Taranis" outputting less than 16 channels? (I am using the "Taranis" with the "XPS" system)
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Old Apr 15, 2014, 07:14 PM
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Quote:
Originally Posted by tande View Post
Do I understand correctly; this is a non/issue with the "Taranis" outputting less than 16 channels? (I am using the "Taranis" with the "XPS" system)
bump the channel count down until the calculated frame rate measurement on the screen comes under 30ms... should be 11 channels for 28.2ms. Anything that or under is rock solid.

I was having seemingly fine success with higher channels and an incorrect frame setting of 12.5... but that appears it may have been illusionary and not recommended now with fix on the way.
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Old Apr 15, 2014, 07:39 PM
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OK...Good.......thanks Arron.......
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Old Apr 15, 2014, 07:41 PM
Xtreme Power Systems
Lake Havasu, AZ
Joined Jun 2005
15,494 Posts
When the Xtreme protocol is integrated into the Taranis it won't be an issue as the frame rate will be 18.5ms, like the XJT D16 protocol.

You must already be using a lower number of channels, or you would not be able to use the Taranis at all...
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Old Apr 16, 2014, 10:59 AM
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United States, NJ, Middletown
Joined May 2012
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Jim/Arron

Thank you both for all your help on figuring this out and the unbelievably quick rework time to make Taranis+XPS for giant scale possible!

Very happy customer here!
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Old Apr 16, 2014, 12:30 PM
Xtreme Power Systems
Lake Havasu, AZ
Joined Jun 2005
15,494 Posts
I have a question for everyone about the Nano's functionality -

Right now when selecting "mixed mode" (where output port 6 sends the Xtreme protocol to the X10+ board, and output ports 1-5 are available for servo outputs), the servo output mapping is set to channels 12-16. I ran into an issue today when testing with a 8 channel transmitter - there is no output at all on the output ports because channels 12-16 do not exist. Does it make sense to change this to perhaps use the last 5 channels of those available on the transmitter? That means with a transmitter having 8 channels, output ports 1-5 would default to channels 4-8. Typically, people won't be using the Nano in mixed-mode to power heavy duty servos, which are typically on channels 1-4 and connected to the X10+. The Nano can of course be changed so the channel mapping is anything after the binding/selecting the output mode. So, I am referring to just the defaults when selecting the output mode to be mixed mode.

Let me know your thoughts. Thanks!
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Old Apr 16, 2014, 02:25 PM
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Hey Jim, not sure I am the most qualified to answer this but I can tell you what James and I have been working on... The setup we are after for a 104" slick with 3 ailerons per wing, dual rudder and dual elevator and using dual nano w/ x10+ is:

X10+: 1-3, LAL
X10+: 4-6, RAL
X10+: 7-8, Rudd
X10+: 9-10, Elev
X10+:11 - Redundant Nano
Nano Master: 11, Ignition
Nano Master: 12, THR
Nano Master: 13, Smoke

For a 50CC - 70CC and setup with single servos on Ail, Rudd and Dual Elevator using X10+ with 1 Nano is:
X10+: 1, LAL
X10+: 2, RAL
X10+: 3, Rudd
X10+: 4-5, Elev
X10+: 6, Ignition
X10+: 7, THR
X10+: 8, Smoke

For our situation with Taranis and the port assignment the only issue was giving up channel 11 and the framerate we had to reassign the ch 11 each time we bound the nanos so that we could send the least number of channels and get the smallest frame rate. The only issue with the default for us was that it skipped ch11 when we were using the redundant nano.

Personally, I prefer to have to explicitly set it, rather than rely on the defaults but thats because we already have to program the x10 to setup for the extra nano so programming the outputs on the nano isnt a big deal. If you are solving for people with less channels that don't want to program outputs, I think your suggestion of the defaults being the highest channel count of the tx would work as even for my situation, it would be the same as the current default if I understand correctly.
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Old Apr 16, 2014, 03:06 PM
Xtreme Power Systems
Lake Havasu, AZ
Joined Jun 2005
15,494 Posts
Right now (existing release code) in mixed mode the Nano automatically maps the 5 outputs as channels 12-16 - regardless of the number of channels your transmitter has! This is obviously not going to help someone with a 9 or 12 channel radio!

So, I have changed the code so now the last 5 highest channel numbers appear on the 5 output ports. For a 8 channel transmitter, that means channels 4/5/6/7/8 appear on output ports 1-5, with output port 6 being connected to the X10+ to provide ALL of the channels. If you had a 12 channel transmitter, then channels 8/9/10/11/12 would appear on output ports 1-5, and again output port 6 would be connected to the X10+. You can use the XDP after setting up the receiver to change the mapping to whatever you like. I think these new defaults for mixed mode make a lot more sense.

When the updated Nano code is released: you need 13 channels total so you should set the Taranis to 13 channels (32.5ms - 100us +) and bind the slave and master. At the end of the bind, select mixed mode for the master (and Xtreme mode for the slave). This will automatically make the master's channels 9/10/11/12/13 appear on output ports 1-5. You would then get channel 11 on output port 3, channel 12 on output port 4, and channel 13 on output port 5. Output port 6 would be connected to the X10+'s main input. The slave Nano would be connected to the X10+'s aux port.

Please also not that the X10+ firmware needs upgraded to work with what you want to do. It's max frame rate is 30ms. I am going to change this to a floating frame rate (like what I had to do to Nano and RFU), so at that point any frame rate would work.
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Old Yesterday, 05:45 PM
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Launceston Arpt, Tasmania, Australia
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[QUOTE= I am going to change this to a floating frame rate (like what I had to do to Nano and RFU), so at that point any frame rate would work.[/QUOTE]
surely, you must have some frame limit, how else can you define a missing frame?
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Old Yesterday, 07:39 PM
Xtreme Power Systems
Lake Havasu, AZ
Joined Jun 2005
15,494 Posts
The frame to frame time is calculated for every frame and 2ms is added to this time and stored in the frame time comparator. If no frame arrives within the comparator time, then the frame is replaced with the last known good frame and last good frame rate time is stored in the frame time comparator, and the process repeats. Using this method allows for frame rates up to 65.535ms, and they can vary on the fly like JR/Graupner frames do.
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