Run the sound modem configuration program as root! It writes to system files. A simple NPN transistor with current limit resistor will work just fine! Setting Up Soundmodem The PTT is either done by VOX (in which case you may need to tweak your TX Delay to give time for the VOX to work, see later) or you can make a PTT circuit from the RTS of your computer serial port to the PTT of your radio. Follow the radio manual instructions to wire it all up and set levels appropriately. The soundcard is coupled so that received audio from the radio goes into the microphone and speaker audio from the sound card is transmitted by the radio. It’s a USB soundcard (cheap £2 Chinese thing, no brains or codec) and a cheap USB RS232 TTL UART interface (PL2303). The hardware I use is a homebrew interface. Xastir, as mentioned, does the mapping for APRS. These include many of the supporting programs that make the kernel’s AX25 support usable outside TCPIP.
#Arduino rtty install
Sudo apt-get install libax25 ax25-apps ax25mail-utils ax25-tools ax25-xtools xastir If you get an error saying that “Package ax25-utils is not available”, try the following (Thanks to Silvio, DO1SIL): Sudo apt-get install ax25-apps ax25-utils ax25mail-utils ax25-tools ax25-xtools xastir We may also like a few extra AX25 programs, such as These are the key programs you will want. This installs two programs: soundmodem and soundmodemconfig which are the modem and the configuration tool respectively. The process is quick and results in something like this:
![arduino rtty arduino rtty](https://i.ebayimg.com/images/g/JBAAAOSw2z9gUNMe/s-l400.jpg)
Install soundmodem from the standard Ubuntu/Debian repository: I compiled the latest version 0.18 from Thomas Sailer’s website and the feature set looked very similar to the standard repository version, so I make no effort to compile the (possibly newer) version.
![arduino rtty arduino rtty](http://4.bp.blogspot.com/-ec-b6A3P4w0/UfYmCDkyYYI/AAAAAAAAAJc/hvxtFayliB8/s1600/20130723_154351[1].jpg)
The program doesn’t report version number or offer it up anywhere. The exact version number of Soundmodem I used is hard to find. These TCP/IP experiments are outside the scope of the basic sound modem and may (in the future) make another article of their own! Install The Software I also extended the settings to experiment with TCP/IP over AX25, for the technical exercise.
#Arduino rtty how to
On this page I will describe how to get the basic network interface working and how that can be used with XASTIR, a amateur radio based digital communication system for real-time exchange of digital information to users on the APRS (Automatic Packet Reporting System) network, 144.8000 MHz in Europe. The software allows a standard PC sound-card to be used as a packet radio “modem” with all processing done on the main computer CPU. Soundmodem is a Multiplatform Soundcard Packet Radio Modem written by Thomas Sailer, HB9JNX/AE4WA.