The lpc-ntpd is a software driver designed to enable communication between the Lindy Precision Clock and MSF radio receiver by providing an accurate time reference for synchronizing digital clocks.
The Lindy precision clock comes equipped with a 2-meter RS232 cable with 9 pin connector and can be easily plugged into any standard RS232 port on your device. I found a few details that will be helpful to get started with this software. For example, to use it, you need to set the DTR and . pins high because they're used for power. Additionally, when the receiver receives a signal, the LED on the device flashes red for every bit it detects, which happens typically once per second. During the first 8 seconds though, it flashes twice per second (depending on the sign of the DUT1).
You also need to adjust the serial port to 50 BPS, 8 bits, with no parity. Further, every bit is sent to the computer in 1 byte, so all buffering must be disabled. Interestingly, it seems that in every byte sent, the signal strength is encoded, though I'm not 100% certain about this. Another important detail to keep in mind is that if a byte read is less than 0x30, then a '1' bit is received. Otherwise, a '0' is received.
This little program comes with a UNIX script that displays the stream received. To use it, compile with gcc -O2 -o lpct lindy_precision_clock-test.c and start with ./lpct. Additionally, you may need to set the serial port to "low latency": setserial -v /dev/ttyS0 low_latency and disable the FIFO of the serial port before use.
I was impressed to see that this software continues to receive updates. The latest release, for example, adds support for the USB version of the clock (option '-b'), includes a parity check, and properly handles summertime. Overall, I found this software to be quite useful if you're a fan of the Lindy Precision Clock MSF radio receiver or want to easily connect the MSF atomic clock radio to an NTP daemon.
Version 1.0.0: N/A