locked Help needed for MAP65 network protocol #map65


Hi to all.
I developing SDR software for LimeSDR-USB (2ch RX 0.1-3.8GHz) and I'm stuck with MAP65 network protocol. So far I managed to form UDP
packets and send them to MAP65, they are displayed but inversed (in the center of spectrum is +/-48KHz and at the both edges is 0Hz). MAP65 in lower
left corner is displaying message Receiving F2 or Receiving F1 (green all the time without any red NILL messages).
When I try to send one RF channel via soundcard (using VAC) it is working fine, decoding on 2m and 70cm Jt65 and Q65 modes but only one polarization.
Where can I find documentation for struct Linrad (from file soundin.cpp, line 339)? Using Wireshark I'm monitoring UDP packets and they look like packets
from Linrad but not 100% sure about first 24 bytes (packet header). Change passband_direction in header has no effect. Maybe I need to change settings
inside MAP65 program?

Goran, yt7pwr

Niels - G8RWG


Thank you Neils for the link, I saw it before. This morning I solve the issue! My starting point was
code page. Since my app is written in C# porting code was neccessary. After analysing Linrad
UDP output I was convince that everything is identical but spectrum was inverted. After even more
analysis I found in MAP65 source code file soundin.cpp file and in function a2dCallback code comment
/Negate odd-numbered frames (not sure why is this done). Now UDP transfer is working in 1ch or 2ch
mode from my app but with Linrad  spectrum is still inverted (not sure about RSPdue).
Now I'm waiting second part of ARRL EME contest to test hardware and software setup.

73 de yt7pwr