PilotAware
British Forum => General Discussion => Topic started by: rg on May 11, 2016, 10:58:39 am
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Apologies if I've missed this somewhere already
Are the PA team now able to share some of the details about the test results on the new hardware. I mean specifically in terms of what types of antenna and where they were mounted in different aicraft?
I'm personally interested in any results from internal setups as I hire aircraft so won't have the luxury of mounting something externally.
Thanks
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Yes this in on the to do list and will pe bublished very soon
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In something of the same vein, can you identify the RF module used in the new shield, Keith - or maybe David? I would be keen to have its specs. If we are to ever see PAW proliferate outside Europe, we will need to find similar devices operating on frequencies that are legal for non-licenced use in the various countries concerned.
By way of explanation, I had been thinking of getting a couple of shields for experimenting here in Australia but realising that would mean that I would end up with two shields that I can't use, along with the two Wireless Devices transceivers that I bought, didn't commission before the October announcement but similarly can't use, I am having second thoughts about that plan. The announced shield prices are not astronomical in themselves but once the exchange rate difference is factored in, the total investment to date starts to add to something sizable. To give some relativity, a cup of coffee here costs ~ $4.50 AUD. As I recall, the same cost me around GBP4.50 in the UK. GBP4.50 is $8.80 at today's rates, so the exchange differential represents considerable loss of buying power for those of us downunder. I think I would be better advised targeting further investment at devices that I can lawfully use.
Bill
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Hi Bill
As you quite rightly say, the specs are actually irrelevent for Australia.
The specification of the RF is ETSI 300 220
The specific band is SRD/ISM 869.40 - 869.65 Mhz
Of course Australia has a different spectrum allocation to Europe
Thx
Lee
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Thanks Lee but as a RF techo in my own right, albeit amateur, I would like to know far more than the generic specs of the frequency allocation in which it operates. I need to focus in on the characteristics of the actual device itself.
Bill
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Thanks Lee but as a RF techo in my own right, albeit amateur, I would like to know far more than the generic specs of the frequency allocation in which it operates. I need to focus in on the characteristics of the actual device itself.
Bill
Hi Bill,
Can you explain your end goal here, I am confused as to the relevence of a device which is not legal in Australia.
So can you explain what is the end result you are trying to achieve ?
Thx
Lee
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£4.50 for a cup of coffee Bill! where was that? Claridges?
I think you've had your face ripped off!
https://www.londontoolkit.com/blog/eats/coffee-shop-chains-in-london/
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I probably was ripped off but even at 2.90 pounds, that would entail me finding near $5.80 to cover the cost were I in London today. Not that it is really relevant to the request I was making.
On Lee's question, my end goal is to try and find a transceiver of equivalent performance but which operates on a frequency which is able to be used legally, licence free in Australia and possibly in NewZealand, although I have yet to explore their licence free ISM allocations. I am therefore interested in its data sheet, since that would be a necessary pre-requisite to comparing its performance specs to those of other devices which may be frequency and standards compliant here. Knowing the relevant European standard and frequency range of 869.40 -869.65 MHz is not particularly helpful. I hazard the guess that even the Wireless Devices transceiver purported to meet those requirements?
If a suitable device can be found, I would hope the team might consider looking to offer a shield that suits the Australian and New Zealand markets and indeed other possible markets too, once it is over the European peak demand. If that is being overly optimistic then I'm afraid PAW is destined to remain Europe-centric.
Bill
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The specific band is SRD/ISM 869.40 - 869.65 Mhz
Be interesting to know how interferance is mitigated from other users of this single slot.
i.e
Fire alarm systems
Wireless audio Individual item tagging Intruder alarm systems
Assistive listening
devices
Asset tracking Home/Office automation
Access control
Remote controllers
Medical
Social alarms/Telecare
Smart meters
Telemetry
Automotive
This is a good one;-
https://stellarsupport.deere.com/site_media/pdf/en/guides/RTK/PFP15164_RTK_Network_869_MHz_EN.pdf
etc
and they use them as repeaters !
John
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The specific band is SRD/ISM 869.40 - 869.65 Mhz
Be interesting to know how interferance is mitigated from other users of this single slot.
i.e
Fire alarm systems
Wireless audio Individual item tagging Intruder alarm systems
Assistive listening
devices
Asset tracking Home/Office automation
Access control
Remote controllers
Medical
Social alarms/Telecare
Smart meters
Telemetry
Automotive
This is a good one;-
https://stellarsupport.deere.com/site_media/pdf/en/guides/RTK/PFP15164_RTK_Network_869_MHz_EN.pdf
etc
and they use them as repeaters !
John
The chipset such radio modules are based on implement a packet based protocol, so anything transmitted is ignored if it isn't in the right format, there are also checksums, group IDs etc. within the RF packet engine. One reason for anyone using these kinds of things NOT to use the default group ID at the RF packet level, so the module ignores anything not 'addressed' to the group. Then Lee's P3I protocol also has a checksum, such that if an RF packet gets through there is an additional checksum to be passed too before the data is used.
These frequencies also have a low duty cycle, for example sending a single data packet once every few seconds. These aren't continuous broadcast systems.
Fundamentally it is mostly handled within the RF chipset, from memory of e-mail exchanges the bridge is based on the Silicon Labs Si4432 chipset.
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On a simpler note, what cabling is needed to get audio alerts piped into intercom so that it can be heard in ones headset?
Cheers,
Deker.
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Raspberry Pi uses a commonly available 3.5mm 4-pole 'TRRS' Jack socket. Plug needs to be wired:-
Tip = Left Audio Channel
1st Ring = Right Audio Channel
2nd Ring = Ground
Sleeve. = Video output (not used)
Be careful, most commercial cables aren't wired that way!
What I did was bought a long commercial lead, cut it in half and worked out the wiring colours by continuity testing. I then made one half up into a mono audio lead to connect via a single phono plug to my Flycom box and it works great.
How you connect the 'open' end will depend on your own intercom/headset system, so I can't help you there I'm afraid.
Regards
Peter
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Raspberry Pi uses a commonly available 3.5mm 4-pole 'TRRS' Jack socket. Plug needs to be wired:-
Tip = Left Audio Channel
1st Ring = Right Audio Channel
2nd Ring = Ground
Sleeve. = Video output (not used)
Be careful, most commercial cables aren't wired that way!
What I did was bought a long commercial lead, cut it in half and worked out the wiring colours by continuity testing. I then made one half up into a mono audio lead to connect via a single phono plug to my Flycom box and it works great.
How you connect the 'open' end will depend on your own intercom/headset system, so I can't help you there I'm afraid.
Regards
Peter
A picture may help some people...
edit: apologies if this image is huge, if a mod wants to shrink it feel free.
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Thanks Jeremy,
I do have that diagram, but when I tried to shrink it to add it to my post, it distorted off screen. Others please note, although the diagram Jeremy has provided is labelled 'Model B+', the Pi 2B also uses the same pinouts.
Regards
Peter
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Doesn't the pinout mean that a standard 3.5mm stereo jack will work, albeit that it shorts the video to ground when doing so?
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Doesn't the pinout mean that a standard 3.5mm stereo jack will work, albeit that it shorts the video to ground when doing so?
Should be fine, I assume Lee outputs both L&R channels, in which case a mono plug could be used as most intercoms etc. are mono?
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was running a pilotaware to Caunton and back yesterday from Long Marston. It was great to be able to watch a Sikorsky G-MCGJ converging on me from my 2 o'clock from about 10 miles out and 700' feet above me just south of Loughborough. Both of us were under a service from East Midlands and got a convergence warning from ATC just before I saw him coming out of the gloom. Very relieved to see him passing behind me rather than in front!
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Buying the commercial lead and chopping it up to work out the connections is a great idea. Trying to solder up the 4 ring jacks is horrible.
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Buying the commercial lead and chopping it up to work out the connections is a great idea. Trying to solder up the 4 ring jacks is horrible.
Agreed!
Even a 'personal stereo' 3 ring is fiddly.
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Hi Doug/Robski,
I bought a commercial 4 pole "TRRS" cable to cut down, as Peter suggested in previous post, but ended up NOT using it. As Paul and Jeremy pointed out a standard 3 pole "stereo" plug will fit into the Pi audio socket and connect with the L and R audio channels, which is all that is needed.
I guess you will have completed your "audio" installation by now, but this post is intended to help others;
You can purchase 3.5 mm 3 pole "stereo" cable sockets from Maplins cheaply, (most towns have a branch, usually situated next door to Halfords). It is easy to solder a cable to it and heat shrink over the cable and connector body to insulate and ruggedise your work.
NB. This socket had two other advantages, it comes with a nut, so it can also be used as a bulkhead connector for fitting to a panel, and the insertion/ pull-out force is high for a plugged in cable, just what you want for an "in-line" connection if this will be a feature of your set-up. I would use this socket over their "open frame" bulkhead socket, any day!
Rather than purchase standard jack to jack audio cables, I bought the "SLIM 3.5mm" variety, via eBay. These are much neater, and will fit into iPad or phone headphone sockets with no problems. They are also much cheaper than Maplin, who only supply the big body jacks on their made up cables.
Regards,
Chris