Verifying Mode S ES ADS-B Out transponder setup - Can PilotAware help?

[Moffrestorer]

Hi John,

I recall that Lee's original build manual for PAW stipulated that the USB to RS232 cable needs to have the PL2303 chipset installed. Could this be your problem?

Alongside this statement is a picture  of a cable assembly having USB at one end and wire pigtails at the other end, rather like the Farnell product that Wobblewing posted a link for above. Not sure that the Farnell one is compliant with the chipset requirement, also Lee suggests this type of cable assembly can be obtained via eBay or Aliexpress for less than a fiver.

I haven't managed to find such a cable on eBay, they are more commonly USB/DB9.

[tnowak]

In the day job we have had mixed success with using USB to RS-232 converter cables to communicate with Cisco routers.
In the old days, when every laptop came with an RS-232 serial interface, it was easy. Now you have to use the (modern) laptop's USB output to communicate with RS-232 devices. As I say - it is a bit hit and miss.

Do you have access to a laptop with a true RS-232 interface? You could see if the laptop sees ADS-B out data out of PAW.
Tony N

[Admin]

Just be careful which RS232/USB you buy, and what your transponder requires.
RS232 or RS232-TTL

RS232 is +/- 12v (inverted logic)
RS232 is 0v/5v

They are totally incompatible

Thx
Lee

[flying_john]

Do you have access to a laptop with a true RS-232 interface? You could see if the laptop sees ADS-B out data out of PAW

Thanks Tony, thats the next step. I have an old laptop with RS232 term program and am going to test what actually comes out of the PAW on the USB connector that has a USB to RS232 adaptor connected to it. Once I have satisfied myself the NMEA sentences are "pouring out" then if it still doesn't work I will have to request more help from Funke.

John

[Andy Fell]

Just be careful which RS232/USB you buy, and what your transponder requires.
RS232 or RS232-TTL

RS232 is +/- 12v (inverted logic)
RS232 is 0v/5v

They are totally incompatible

Thx
Lee

Yes, there are different types.. The one I linked to above is for RS232 +/-12V, not TTL (3V3 or 5V) ... you can get the TTL version if desired.. I figured that the Transponder wanted to see genuine RS232 level signalling (+/-12V)

[Andy Fell]

Software drivers cannot be loaded in into the PAw. What is needed is a standalone hardware solution, i.e usb to 232 protocol + level shifting.

John

The operating system running on the PI needs to know about the USB<>RS232 converter chip that you are connecting to your USB port, so it does need to support the chipset you are using.. FTDI is a very common one, so it should work..

[Paul_Sengupta]

At the top of the page it says it has to be the PL2303 chipset.

These are the cheapest ones. I recently bought two from China for under 4 quid delivered (for the two, not each!) to supplement the ones I already had. In fact, I've just given one away, they're so cheap. Got a couple for work, and they're so cheap it's not worth putting in an expense claim! 

I also bought an FTDI one but I can't for the life of me remember where I put it.

[scsirob]

Do note that those cheap PL2303 ones are actually fake chips copied in China, not from Prolific. They work OK, but Prolific is doing everything they can to make them fail in their Windows drivers. Built-in Windows WHQL drivers from Windows 8(.1?) and up refuse to start when they detect a fake chip.

You can still find older drivers online that work with these fake chips, but chances are you get more software than you bargained for. I have had a number of downloads flagged as infected with virus and trojans. So be careful out there.

For PAW and Linux it is less of a problem as these chips work fine with the generic Linux kernel drivers.

[Andy Fell]

does FTDI not work with the standard RPi style linux OS, then?  I thought it did....

Here are the drivers...?
http://www.ftdichip.com/Drivers/D2XX.htm

[flying_john]

So another wasted morning. I cant seem to prove that there is any serial data coming out of the PAW from the Top R.H USB connector.

I have a test dumb terminal set to 4800 N 8 1.  I prove this is working by connecting the USB adaptor lead to a laptop running a TTY session and I can send data out of the laptop USB port through the Convertor (that has the correct chip set) and I get the characters I type on the laptop appear on the dumb terminal great.  If I now replace the laptop with the PAW, no  output sentences are see at all.

Am I missing something ?

[Admin]

Hi John

Can you post a screenshot of the paw home page and configure page,
I want to see what is reported as usb devices, and how the ports are
Configured

Thx
Lee

[flying_john]

O.k but not back at airfield till Tuesday.

[flying_john]

Sorted  now - see the other thread.

I was connected to port 3 instead of port 1. No wonder there was no data.

[Admin]

Sorted  now - see the other thread.

I was connected to port 3 instead of port 1. No wonder there was no data.

Excellent!

Thx
Lee

[SteveHutt]

Re: "Verifying Mode S ES ADS-B Out transponder setup - Can PilotAware help?" I guess the info below means we are virtually there.

The new LAA MOD 7 and MOD 14 forms that detail the ADS-B Out verification using PilotAware have been published.

See: http://www.lightaircraftassociation.co.uk/engineering/StandardForms/LAA-MOD%207%20-%20Avionics%20Installation.pdf
and: http://www.lightaircraftassociation.co.uk/engineering/StandardForms/LAA-MOD-14%20-%20ADS-B.pdf

MOD 7 is for a full avionics approval. MOD 14 is for adding ADS-B Out with a non-certified GPS onto an already approved Mode S ES transponder.

Just need the BMAA docs now.

Thanks again to Lee and the PilotAware Team for making this possible.

Steve