NMEA out to transponder.

[bnmont]

I am using the ublox external gps on my PAW unit.
Can I get nmea out to feed my transponder? (adsb Trial)
If so how?

Thanks Brian

[Admin]

I am using the ublox external gps on my PAW unit.
Can I get nmea out to feed my transponder? (adsb Trial)
If so how?

Thanks Brian

Hi Brian,
I Provided Ian Fallon with an early release of this feature, and I am pretty happy with the results (Ian please comment). At the moment I am only producing $GPRMC messages, which is the requirement for the TRT-800.

Do you know what messages your transponder wants to receive ?
I am guessing it is probably the same, but we should probably get a straw poll of what transponders need which $GPxxx messages.

If it appears that different transponders need a different mix of messages, I will need to make this configurable, so any input you can provide would be helpful.

I will try and get a release out this weekend with this feature included, how does that sound ?

Thx
Lee

[ianfallon]

I haven't been through the LAA mod (14) process yet so of course I haven't turned it on and tested it, but ... I think we can be quietly confident it works let's put it that way.

See here for the LAA paperwork:

http://www.lightaircraftassociation.co.uk/engineering/StandardForms/LAA-MOD-14%20-%20ADS-B.pdf

[ianfallon]

Basically you will need an RS232 input into your transponder, ideally 9 pin female connector.
If you don't have this you'll need to do some research and buy or build an appropriate cable based on your transponder. (If you have an EASA aircraft I seriously doubt you can legally do any of this! Permit aircraft can but see the link on the previous post for the mod form - which has to be signed off by your inspector).

Then one of these:

     http://www.ebay.co.uk/itm/271928707196?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

     (be careful to get the right type - thanks Lee for the pointer to this one)

to connect the PAW to it.

Then configure the transponder for NMEA format messages over RS232 (at 4800 baud).
Then configure the PAW USB port setup for the port you plug it into as "Transponder" type (available in forthcoming PAW software) and 4800 baud.

[Admin]

Yes - regarding USB/RS232, there are 2 types RS232 and RS232-TTL
do not get the TTL version the logic levels are inverted and not the correct voltage

one other note, the TRT-800 only takes 4800 baud for NMEA, other types may accept different baud rates.
At present you can select 4800/9600/57600
This should cover the wide majority

Thx
Lee

[bnmont]

I have a TRT800H so should be good?

Thanks

[ianfallon]

I have a TRT800H so should be good?

Thanks

You have a PM !

[Moffrestorer]

Hi Lee,

Can you please add the following to suit Becker BXP 6401-2;

EIA-232C or EIA-422 interface with serial asynchronous transmission parameters: 4800, n,8,1 and TX data with NMEA-0183 protocol GGA and VTG sentences.

Many thanks

[Sierrakilo]

Just put together a Pilot Aware unit and am watching the inbounds to LGW as they overfly my home.Brilliant !
Would also like to connect to my Mode S Transponder when I get the PAW sorted for the aircraft.
Funkwerk TRT800H
from the manual .... NMEA-Format, data format RMC is
expected. 4800 Baud rate

[Mike P]

I have a Trig TT21 and include below the section from the Installation Manual which details the requirements for GPS input. It looks as though it can accept a number of different protocols but the NATS Non Certified GPS Trial information document states the following requirements for the GPS:

"As a minimum, any GPS that outputs
NMEA 0183 sentences over an RS-232
link."

It looks as though using the NMEA protocol sets the required SIL and SDA values for the trial on many transponders.

Mike

*****Extract from Trigg TT21/TT22 Installation Manual*****
5.6.9 GPS Position Input
The GPS position input is required to support ADS-B functionality. The GPS
position input is an RS232 input to the transponder. The ADS-B features are
optional – no GPS is required for normal Mode S Elementary Surveillance.
The TT21/TT22 GPS input can recognise the following protocols:
    Industry standard “Aviation” protocol
 NMEA 0183 protocol
 Freeflight and Accord NexNav GPS proprietary protocols
 Garmin ADS-B protocol, including ADS-B plus
 Trig ADS-B protocol
 C199 TABS compliant GPS using NMEA protocol
The interface speed can be selected between 4800, 9600, 19200 and 38400
bps.

[Richard]

Yes, Just been looking at that section. On the new updated firmware within the transponder. There is no option to set the SIL=0 and SDA=0 The only option is to set the GPS Certification Level As I understand it, it should be set to D the low level....

I have just had my TT21 firmware updated and it is sitting on me desk until Sunday when it gets put back into the aircraft. I will go through the settings to see whats new.

Trig do the Upgrade for Free, just send it back to them. Posted to them and back in my office in 3 days. Support is excellent.

[Moffrestorer]

Basically you will need an RS232 input into your transponder, ideally 9 pin female connector.
If you don't have this you'll need to do some research and buy or build an appropriate cable based on your transponder. (If you have an EASA aircraft I seriously doubt you can legally do any of this! Permit aircraft can but see the link on the previous post for the mod form - which has to be signed off by your inspector).

Then one of these:

     http://www.ebay.co.uk/itm/271928707196?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

     (be careful to get the right type - thanks Lee for the pointer to this one)

to connect the PAW to it.

Then configure the transponder for NMEA format messages over RS232 (at 4800 baud).
Then configure the PAW USB port setup for the port you plug it into as "Transponder" type (available in forthcoming PAW software) and 4800 baud.

Probably silly questions, but does the  USB - RS232 Dsub cable need the PL2303 chip set as stated in PAW construction manual? Will the drivers need to be loaded into the Pi, or will this be taken care of by Lee in his update?

Thx

[Moffrestorer]

Hi Lee,

Another question for you.

If the PAW is outputting NMEA to the mode S, can it be arranged so that it does this without a tablet being connected via the Wi-Fi interface? The PAW will be obtaining GPS signals from a ublox plugged directly into the Pi. Some others in our group, use Garmin 496's that currently won't interface with PAW. It would be nice if we could still transmit ADSB out under these circumstances.

Thx.

[Admin]

Hi Lee,

Can you please add the following to suit Becker BXP 6401-2;

EIA-232C or EIA-422 interface with serial asynchronous transmission parameters: 4800, n,8,1 and TX data with NMEA-0183 protocol GGA and VTG sentences.

Many thanks

I can do this.
Thx
Lee

[Admin]

Just put together a Pilot Aware unit and am watching the inbounds to LGW as they overfly my home.Brilliant !
Would also like to connect to my Mode S Transponder when I get the PAW sorted for the aircraft.
Funkwerk TRT800H
from the manual .... NMEA-Format, data format RMC is
expected. 4800 Baud rate

Supported in version 20151030
Thx
Lee