2.4 modules discontinued!

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jmendoza
Posts: 167
Joined: 18 Feb 2018, 23:07

Re: 2.4 modules discontinued!

Post by jmendoza »

Thanks you Mike for the clarifications.
Do you have a recommendation/ preference when it comes to the i-Range, or the Jumper 4-in-1?

Who has the best price on these?

I have several 3.3V Arduinos( Pro-mini Strong) here I ordered by mistake,so this would be a good application for them, do you not think?
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Mike_K
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Re: 2.4 modules discontinued!

Post by Mike_K »

Hi Jay

If cost isn't an issue I'd recommend the Jumper multi-protocol module for a few reasons.

1. It has both FCC and CE approval, so you should be good to use in the US and Europe legally.
2. Quite a few guys at clubs I fly with, use Jumpers without any issues, they say it is robust and reliable.
3. There is documentation available (albeit limited)
4. It's the only one I've test flown, the others have only been used on the bench so far.

But be careful where you buy Jumpers from, as there are a lot of Jumper clones out there (yes the Chinese even clone premium Chinese brands). Below is a link to the Jumper website with the multi-protocol module

https://www.jumper.xyz/portal.php?mod=view&aid=6

The ones on Banggood don't look anything like the original and don't have the manual selection switch, so I'd avoid them.

https://www.banggood.com/Jumper-JP4IN1- ... rehouse=CN

The i-RangeX I've got has no FCC or CE mark on it (or on the packaging I received it in), so it is used at your own discretion. But it does work well and I've tested it extensively on the bench. And it gets good reviews. Basically the Jumper and all the others are identical, as they use the same firmware (open source) and hardware (again open source), it's just some have gone through the approval process, most haven't.

But the Jumpers FCC and CE approvals come at a cost, I bought mine from a UK drone distributor and it cost me 40% more than the i-RangeX from Banggood. I will use Jumpers for any conversion I do for others but will probably use i-RangeX or similar for my own projects.

As I bought my Jumper from the UK, I can't really recommend where you should buy it from, but make sure it looks like the one on the Jumper website.

Mike
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ozrs
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Re: 2.4 modules discontinued!

Post by ozrs »

Note - there is currently a drama unfolding which may effect multi-protocol-module compatability in the future.

https://www.rcgroups.com/forums/showthr ... o-affected
Richard
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Mike_K
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Re: 2.4 modules discontinued!

Post by Mike_K »

ozrs wrote: 27 Jan 2020, 02:20 Note - there is currently a drama unfolding which may effect multi-protocol-module compatability in the future.

https://www.rcgroups.com/forums/showthr ... o-affected
Thanks for that info. A quick read of the thread and it would appear the problem is isolated to the FrSky X/D16 protocols and doesn't affect the earlier D8 (or V8) protocols. And all other protocols such as the DSM2/DSMX are obviously not affected.

But something I learned over the weekend with the multi-protocol module, is that any protocol using the CC2500 chipset (all FrSky protocols and Futaba S-FHSS) ideally needs individual tuning. It appears that the xtal in the CC2500 module has some variation and needs tuning to obtain maximum range. And you can only do that when installed in an OpenTx based transmitter. I'm begging to wonder if the multi-module is such a good choice? Having said that, in blissful ignorance, I range checked my model with FrSky D8 Rx and flew it without an issue.

So with DHT and OrangeRx DIY out of stock, XJT modules in need of an update, we have little option but to use the Multi-Modules or FlySky modules. Or I guess, go back to using 35MHz?

Mike
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Wayne_H
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Re: 2.4 modules discontinued!

Post by Wayne_H »

Thanks for the info Richard.

My quick reading of the thread left me thinking the same as Mike - it doesn't affect the earlier D8 (or V8) protocols.

I was very interested in Mike's comments that any protocol using the CC2500 chipset (all FrSky protocols and Futaba S-FHSS) ideally needs individual tuning. I hadn't heard this before. In practice, I've never had a range issue with a multi module running D8 or V8 protocols, with either genuine Frsky or Frsky compatible Rx's.

Range issues with my mk.1 eyeballs - now that is a whole other story :lol:
Cheers,

Wayne
Once a Retrobate, always a Retrobate............ ;)
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Mike_K
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Re: 2.4 modules discontinued!

Post by Mike_K »

Wayne_H wrote: 27 Jan 2020, 11:46 I was very interested in Mike's comments that any protocol using the CC2500 chipset (all FrSky protocols and Futaba S-FHSS) ideally needs individual tuning. I hadn't heard this before. In practice, I've never had a range issue with a multi module running D8 or V8 protocols, with either genuine Frsky or Frsky compatible Rx's.
Wayne, I couldn't believe that they recommend you tune them, it sounds very much back to the days of 27MHz and valves :D

But the link is here if you've got an OpenTx radio:

https://github.com/pascallanger/DIY-Mul ... _Tuning.md
Wayne_H wrote: 27 Jan 2020, 11:46 Range issues with my mk.1 eyeballs - now that is a whole other story :lol:
I know the feeling. I've been told by a few club mates that I'm flying lower and closer to myself recently and I realised it isn't because I've become more proficient as a pilot, but because I can't bloody well see the model when it's too high or too far away. New glasses needed?

Cheers

Mike
Martin
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Re: 2.4 modules discontinued!

Post by Martin »

My multiprotocol module (in a Taranis) has to be tuned for the FrSky protocols to even bind. Once I discovered the optimum value (-42 in my case) then I just apply it to all new model memories when setting them up. Of course, this is easy with a Taranis but would be impossible if just trying to use the rotary protocol-selecting switch.

Finding the optimum value on the Taranis is easy - you just alter the tuning value up and down until control is lost, note down the limit values and choose a number half-way between those limits. There seems to be a range of around plus or minus 20 around the optimum value where there is no apparent reduction in operating range or reported signal strength.

It's possible to alter the default tuning value by editing and recompiling the module firmware source code - but that would be beyond most casual users, and you'd need a transmitter like a Taranis in the first place to find what the optimum tuning for your module was.

Interestingly, many of the other protocols - the Spektrum DSM and the FlySky ones for example - don't need any tuning.

I'm not sure whether the newer multiprotocol modules are better than mine (which was an early example).

I assume that the "ordinary" FrSky modules that only do FrSky protocol(s) are pre-tuned at the factory before being sold - likewise all the receivers
jackdaw
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Re: 2.4 modules discontinued!

Post by jackdaw »

Those interested in this 'tuning' thing may wish to view this video produced by our cousins over the pond.
https://www.youtube.com/watch?v=umXUU45LsqA
I may be wrong but I thought our 2.4gHz Rx were 'wide open' when it comes to the front end RF section. Surely this 'tuning' is a matching of the base frequency that generates the spreading pulse train and speed of 'hopping' etc. I stand to be corrected(well actually I'm sitting in the corner with my dunces hat in hand ready to put on my head)
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ozrs
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Re: 2.4 modules discontinued!

Post by ozrs »

Wayne_H wrote: 27 Jan 2020, 11:46 I was very interested in Mike's comments that any protocol using the CC2500 chipset (all FrSky protocols and Futaba S-FHSS) ideally needs individual tuning. I hadn't heard this before. In practice, I've never had a range issue with a multi module running D8 or V8 protocols, with either genuine Frsky or Frsky compatible Rx's.
As I understand it, you can only tune if using a multi-protocol-module in combination with a TX running OpenTx.

Presumably all genuine FrSky stuff is factory tuned to a specific reference, so further tuning at bind is not required. I guess that this means that tuning is only necessary when using a mix that includes non genuine FrSky gear.
Richard
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Mike_K
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Re: 2.4 modules discontinued!

Post by Mike_K »

I don't think I can recommend the 4-in-1 multi modules for use with FrSky Rx with transmitters using the ppm input such as our conversions. With OpenTx transmitters such as Jumper and Taranis, they're great. And with Spektrum Rx, they appear fine.

I borrowed my Taranis yesterday evening (or rather got it back as I'd lent it out) and tried out the Jumper and iRangerX 4-in-1 multi modules with a FrSky D8R-II Rx and a V8R4-II to see what the "tune" value was. With the Jumper, we arrived at a figure of -4, but the iRangerX it was -27 (using the method in the YouTube video linked to by Alan). It was the same value for both Rx, so once your 4-in-1 multi module is tuned for a D8 Rx, it appears you can use the same value for a V8.

But both modules range check OK, so I don't know how far off things have to be before the range is affected. And Martin said his module wouldn't even bind without "tuning", which is a worry.

So if you really want to use a 4-in-1 multi-module with our conversions with FrSky D8 Rx, I suggest you buy a cheap Jumper T16 or FrSky with an external JR module slot and check the "tune" value is fairly near the centre. If it is near the centre, then you're good to go. If the "tune" is too far out (whatever that value is?) then sell it on eBay. Hardly scientific, but the best I can suggest at the moment.

Mike
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