Hello Jan,

what devices are you using?

Happy Landings

Ubi Sumus

@Jan

Just checked: sending PFLAA to port 2000 shows the traffic in EV 4.0.17

Thanks very much. Have you sent over TCP? Can you please try TCP?

Jan

I'm using UDP only. For EV4 you need GPRMC and PFLAA only, where as EV3 needs additional GPGSA for data accuracy. In

EV4 setup folder you find a file named PFMSWiFiExternalDevicesConnections.xml where you can check the ports used.

Thanks. EV3 definitely works without GPGSA. I could not find the XML settings file you mentioned in /Android/data/com.pocketfms.easyvfr4/files. I dont have my tablet rooted, so I do not have access to data partition. I will experiment with UDP.

Jan

I have created this very basic script to send UDP datagram and I am using perfectly valid NMEA sentence. Yet it does not show in EVFR4. May I know why please?

import socket
import time
UDP_IP = "127.0.0.1"
UDP_PORT = 2000
MESSAGE = "$PFLAA,0,0,-19555,1094,1,49D093!CSA922,215,,121,2880,0*57"
while True:
  print ("UDP target IP:", UDP_IP)
  print ("UDP target port:", UDP_PORT)
  print ("message:", MESSAGE)
  sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) # UDP
  sock.sendto(MESSAGE.encode('utf-8'), (UDP_IP, UDP_PORT))
  time.sleep(1)

From my knowledge the format of PFLAA doesn't look correct.  I used FLARM DATA PORT SPECIFICATION Date: 2015-06-11

Try using following sentences:

$PFLAA,0,11130,3893,-1135,1,3D1212,92,0,42,0,8*2D
$PFLAA,0,-2993,1244,-1208,1,2B8765,124,0,67,0,8*0C
$PFLAA,0,9718,2215,-667,1,3C8B12,40,0,174,0,9*68
$PFLAA,0,13,7369,1762,1,3D0012,92,0,52,0,3*37
$PFLAA,0,13755,-470,521,1,3CACBB,104,0,45,0,1*1D

Thanks very much. I used third sentence from your list and it does not work either. Maybe there should be some indication that connection to FLARM is active as written in some other post.

May I please ask for working script that I clould use for testing? It is Android device.

Thank you.

All sentences above are correct and show traffic as expected.

This code https://github.com/transmitterdan/VDRplayer   runs fine using UDP and port 2000 reading attached file (unzip before using)

Thank you. Do you use IP address 127.0.0.1? I have checked communication of EV4, it listens on 192.168.1.1, 1.2.3.4, 169.254.1.1, but never on 127.0.0.1. Could this be bug that FLARM IP setting are never considered? Thanks.

Yap,  used 127.0.0.1  and is working as expected on Windows. Is port 2000 already used by other software? A port can only be opened once

Hi Jan,

I have asked our head developer Rob to take a look to this topic. He is currently quite busy with a huge beta release this week. After that, he can help you for sure.

In the meantime, have you tried port 4000? And do you have [Monitor for FLARM equipment ] enabled in EasyVFR 4? This needs to be enabled in order to let EV4 listen over TCP. You find it at [EasyVFR 4 menu] -> [System] -> [Electronic Conspicuity Settings].

Note that EV4 by default listens over UDP. That is a far more reliable connection. Enabling to Monitoring for FLARM equipment (via TCP) when not connected to FLARM equipment can result in unstable behaviour of the application. Best is to disable it when you do not need it.

Cheers,

Tim

I did some more research on your code snippet. Following findings:

1. traffic is not displayed in EV without current position, you need to add at least GPRMC to your transmission
2.  you need to terminate your sentences with a line feed.
3. "$PFLAA,0,0,-19555,1094,1,49D093!CSA922,215,,121,2880,0*57" is not a valid, check specifications mentioned earlier

The snippet below works fine in EV4 and EV3:

import socket
import time
UDP_IP = "127.0.0.1"
UDP_PORT = 2000
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) # UDP
print ("UDP target IP:", UDP_IP)
print ("UDP target port:", UDP_PORT)
GPGSA = "$GPGSA,A,3,04,05,06,09,12,20,22,24,25,26,28,30,1,1,1,*02\r\n"
GPRMC = "$GPRMC,132615,A,5335.202,N,01007.0446,E,100,120,190420,1.48,W*67\r\n"
PFLAA = "$PFLAA,0,-4791,389,-50,1,3D0012,139,0,51,0,3*33\r\n"
## NOT_OK = "$PFLAA,0,0,-19555,1094,1,49D093!CSA922,215,,121,2880,0*57"
while True:
  print ("message:", GPGSA)
  sock.sendto(GPGSA.encode('utf-8'), (UDP_IP, UDP_PORT))
  print ("message:", GPRMC)
  sock.sendto(GPRMC.encode('utf-8'), (UDP_IP, UDP_PORT))
  print ("message:", PFLAA)
  sock.sendto(PFLAA.encode('utf-8'), (UDP_IP, UDP_PORT))
##  print ("message:", NOT_OK)
##  sock.sendto(NOT_OK.encode('utf-8'), (UDP_IP, UDP_PORT))
  time.sleep(1)

Hello Ubi, thanks for your help. I finally got it working. Compared with normal FLARM device, with my software emulator, I am even able to get position of small planes equipped with Mode-S transponder that do not broadca

st their position. Some observations for others:

• EV4 does require both $GPGSA and $GPRMC sentences and requires correct checksum
• EV4 always listens on UDP 127.0.0.1:2000 no matter what IP address is set in Electronic Conspicuity Settings.

Looks like I can now use EV4, great product.

Hello once again. I may have discovered a catch.

In the specifications of $PFLAA sentence the fourth parameter is relative altitude to the reference altitude (of your own airplane). Since reference altitude is (most probably) taken from external device in the similar way as reference position, from $GPRMC sentence, it is always zero, because $GPRMC does not contain altitude at all. 

So the displayed relative altitude of other traffic in EV4 is not correct, it is actually relative to 0ft AMSL. EV4 should add current altitude to relative altitude that it receives in $PFLAA.

What helped me is to add current altitude to value in $PFLAA before I send it to EV4 over UDP. Then the relative altitude of other traffic in EV4 is displayed correctly.

Jan

Altitude is taken from GPGGA

OK I have added emulation of $GPGGA sentence and EV4 now works fine. I am going to use it - how can I then change thread title from "Still unusable" to "Great evolution"? 🙂

By the way, is there any way how to properly EXIT the EV4? I did not find anything. When I want to restart it (because of tests of UDP I want to reset buffer), I just have to manually kill app in Android. This way sometimes destroy settings and I have to set everything again... So EXIT button that properly closes files would be very handy...

@Jan

what specifications did you use for PFLAA? So far I did not know that <ID> can be extended with additional info like registration, type. Can you provide a doc or link for that?

Many thanks in advance

Ubi Sumus

Hello Ubi,

I used specs that I found here. When I was messing up with my FLARM emulator for EV3, I discovered that the 8th parameter, Turn Rate, can be also string value and is displayed on the EV3 screen. It is same with EV4, so I am replacing turn rate with aircraft type and registration. If known, I also add destination airport after registration. The example is here:

$PFLAA,0,5956,7401,253,1,24624a53,107,P28A_OK-JIR_,43,0,0*

Jan

Hello Jan,

many thanks for the link. I checked that, but I still could not find any details about extending the <ID> tag like you did in 49D093!CSA922.

No idea if 24624a53,107,P28A_OK-JIR_ is a generally valid option.

Ubi

Hello Ubi, specs for that 8th field say "The target’s turn rate. Positive values indicate a clockwise turn. Signed decimal value in °/s. Currently omitted.", so I am lucky that EV3 and EV4 accepts and displays any value or short string I put there.

If you are asking where I get aircraft type and registration, I can not disclose publicly, but I can tell you over whatsapp (+420.606.633.376).

@Rob

many thanks for that, I'll implement it in easySim

Have a great WE