An excellent choice for remote control of the rotator is using an ARS-USB Unit connected to a Raspberry Pi (Aka RsPi). In this way, you do not need a computer 24 hours on. There is plenty of information on the Internet about the Raspberry Pi, therefore, the scope of this section will not go beyond basic operation and wiring of the RsPi. It should keep in mind that RsPi is a computer with Linux operating system The idea is as simple as installing a program on the RsPi to route traffic received by TCP/IP to the USB port (ttyACMx) where the ARS-USB is connected to. There are several options available on the internet that do just this, but for ease and simplicity we will use a program called ser2net. Thus once you set this ser2net program, traffic TCP/IP port defined will be routed to the ARS-USB. And from the other site – and that is where we want to access the antenna rotor, we will use the ARSVCOM program. Only in this case, it has been set indicating that the “engine model” in this case is “remote TCP/IP“.
The ARS-USB plugs into one of the USB ports on the RsPi (any of them). Automatically ARS-USB is detected as a serial port, that Linux is known as a tty port. An available serial port will be presented as ttyACM0. If there is other serial port present it will be called ttyACM1 (or ttyACM2 and so on). Linux, unlike Windows, doesn’t need any driver, and immediately recognizes the ARS-USB as a serial port.
Since we want to access the ARS-USB from TCP/IP (either the local network or Internet), we have to install and configure a program that allows us to precisely map a TCP/IP port to this serial port (ttyACMx) where the ARS-USB is connected. This program is called: ser2net and does just what we need.
Ser2net service installation is simple: sudo apt-get install ser2net Now you edit the configuration of the service, which will be in the directory: /etc/ser2net.conf To edit it, type: sudo nano /etc/ser2net.conf Go to the end of the file, remove the examples that come by default and type the following line: 6000:raw:600:/dev/ttyACM0:38400 8DATABITS NONE 1STOPBIT In this example, the RsPi listens on port 6000 and sends the traffic to the serial port ttyACM0. If the ARS-USB is in a different port, replace ttyACM0 with the correct port. To automatically start the service, you must type: sudo /etc/init.d/ser2net restart Now all connections to this port will be routed to ARS-USB. All that needs to be done now is to configure the ARSVCOM as a Remote Rotor and configure the remote IP and Port used in RsPi. Then you must activate the connection, the ARSVCOM will connect to the RSPI and the ARS-USB can control it as if it were locally.
The RSPI + ARS-USB combo is an elegant and inexpensive solution for antenna rotor control in Remote Stations. The RsPi is a gateway between TCP/IP and the serial port of the ARS-USB, but can also perform other tasks simultaneously, such as control of a weather station, APRS server, etc… Also the same RsPi can support several ARS-USB units or similar devices as RemoteBox or StackMain. You must add a line peer device you want to use and select different ports for each one at the ser2net.conf file.