rt_x10 is a kernel driver that offers real-time connectivity to the X10 "two way power line interface" (TM523 model), allowing for efficient data transfer with minimal latency.
To utilize this software, a "two way power line interface" module (Model TW523) is required, along with a connection circuit attached to a serial port. In order to properly tie these signals together, the 60 Hz "zero-crossing" signal is attached to CTS, the X10 "receive" signal is connected to DSR, and the X10 "transmit" signal is connected to DTR. Rather than extending the required interface circuitry with additional logic gates and counters, the software implements real-time polling to sample the pulse windows.
The rt_x10 software is a kernel module that works specifically with Linux RTAI but can be modified to work with other similar infrastructures. Once properly installed, this module writes X10 codes to /dev/rtf0 whenever they appear on the power line and sends X10 commands written to /dev/rtf1 over the power line. The software also includes two basic userspace example programs, recvx10 and sendx10, which can serve as a basis for a more complex program tailored to specific sensor, light, and appliance configurations.
In summary, rt_x10 may not offer seamless automation without possible glitches but is an affordable option for those seeking a basic yet reliable home automation system. Its reliance on the X10 protocol calls for additional hardware and a connection circuit, but its well-documented nature makes it straightforward to implement with the rt_x10 software.