DSD NXDN support: updated documentation

Readme.md

@@ -244,6 +244,7 @@ This is the `demoddsd` plugin. At present it can be used to decode the following
   - dPMR
   - D-Star
   - Yaesu System Fusion (YSF)
+  - NXDN
 
 It is based on the [DSDcc](https://github.com/f4exb/dsdcc) C++ library which is a rewrite of the original [DSD](https://github.com/szechyjs/dsd) program. So you will need to have DSDcc installed in your system. Please follow instructions in [DSDcc readme](https://github.com/f4exb/dsdcc/blob/master/Readme.md) to build and install DSDcc. If you install it in a custom location say `/opt/install/dsdcc` you will need to add these defines to the cmake command: `-DLIBDSDCC_INCLUDE_DIR=/opt/install/dsdcc/include/dsdcc -DLIBDSDCC_LIBRARIES=/opt/install/dsdcc/lib/libdsdcc.so`
 
@@ -253,13 +254,6 @@ Although such serial devices work with a serial interface at 400 kb in practice
 
 Note that this is not supported in Windows because of trouble with COM port support (contributors welcome!).
 
----
-⚠ Since kernel 4.4.52 the default for FTDI devices (that is in the ftdi_sio kernel module) is not to set it as low latency. This results in the ThumbDV dongle not working anymore because its response is too slow to sustain the normal AMBE packets flow. The solution is to force low latency by changing the variable for your device (ex: /dev/ttyUSB0) as follows:
-
-`echo 1 | sudo tee /sys/bus/usb-serial/devices/ttyUSB0/latency_timer` or `sudo setserial /dev/ttyUSB0 low_latency`
-
----
-
 Alternatively you can use [mbelib](https://github.com/szechyjs/mbelib) but mbelib comes with some copyright issues (see next). If you have mbelib installed in a custom location, say `/opt/install/mbelib` you will need to add these defines to the cmake command: `-DLIBMBE_INCLUDE_DIR=/opt/install/mbelib/include -DLIBMBE_LIBRARY=/opt/install/mbelib/lib/libmbe.so`
 
 Possible copyright issues apart (see next) the audio quality with the DVSI AMBE chip is much better.
@@ -353,7 +347,7 @@ Install cmake version 3:
 
 <h3>Prerequisites for 16.04 LTS</h3>
 
-You need to install the ffmpeg v.3 suite. Therefore you will need to add this PPA to the sources list using this command:
+For DATV demodulator support you need to install the ffmpeg v.3 suite. Therefore you will need to add this PPA to the sources list using this command:
 `sudo add-apt-repository ppa:jonathonf/ffmpeg-3`
 
 Then do `sudo apt-get update` and go to the next step. Alternatively if you have an older version of ffmpeg suite already installed just do `sudo apt-get dist-upgrde`.

plugins/channelrx/demoddsd/readme.md

@@ -28,10 +28,12 @@ Note also that this is not supported in Windows because of trouble with COM port
 Alternatively you can use software decoding with Mbelib. Possible copyright issues apart (see next) the audio quality with the DVSI AMBE chip is much better.
 
 ---
-⚠ Since kernel 4.4.52 the default for FTDI devices (that is in the ftdi_sio kernel module) is not to set it as low latency. This results in the ThumbDV dongle not working anymore because its response is too slow to sustain the normal AMBE packets flow. The solution is to force low latency by changing the variable for your device (ex: /dev/ttyUSB0) as follows:
+⚠ With kernel 4.4.52 and maybe other 4.4 versions the default for FTDI devices (that is in the ftdi_sio kernel module) is not to set it as low latency. This results in the ThumbDV dongle not working anymore because its response is too slow to sustain the normal AMBE packets flow. The solution is to force low latency by changing the variable for your device (ex: /dev/ttyUSB0) as follows:
 
 `echo 1 | sudo tee /sys/bus/usb-serial/devices/ttyUSB0/latency_timer` or `sudo setserial /dev/ttyUSB0 low_latency`
 
+Newer kernels do not seem to have this issue.
+
 ---
 
 <h2>Mbelib support</h2>