On receipt of Bulletin C, can you arm this clock to display the upcoming leap second? That's a feature that I would desire.
Brooke Clarke wrote: > Hi: > > I've got the Precision Clock to work and have some questions about the > priority of the features. As it is now the clock allows user selection > of the input frequency at power up that determines the instruction clock > for the PIC micro controller. The choices are 2.5, 5, 10 or 20 Mhz. > The clock displays on line one HH:MM:SS and on line two Day of Week, > YYYY, Mon, Day of Month. The leap year testing uses the 4, 100 and 400 > year rules and so you can determine the day of the week for any Georgian > calendar (1583 onwards) date. > > Setting is by means of 4 buttons, Right, Left, Increment, Decrement. > This is very intuitive and quick. During setting the clock continues to > keep time. Also a new data field to the right of the seconds appears as > 4 hex digits to allow moving the LED/1 PPS output pulse in 1 ms steps. > > If the input frequency fails then all the fields that can blink do blink > and the clock stops. Pressing and holding Right or Left for a few > seconds clears the blinking and restarts the clock using the input > frequency that was selected at power up. > > For more see: > http://www.pacificsites.com/~brooke/PRC68COM.shtml#PC3 > > Now for the possible next features to be added. It would be nice to get > some feel for how important they are: > > (1) Synchronize the 1 PPS output rising edge to be near a 1 PPS input > pulse on a one time basis (the 1 PPS edge will have an error of a few > instruction cycles which are each 4/Fin long). If this was done the > manual setting would be removed. > > (2) Add another mode of operation where the clock runs on it's internal > RC oscillator and the timing is determined by an external 1 PPS that > needs to always be connected. > > (3) Add a backup Real Time Clock with it's own coin cell battery to > allow using the clock in a portable application and allow the clock to > be shipped while running. The chip has a 0.1 ppm aging trim capability > and there could be a provision to automatically trim it when one of the > above precision input frequencies is applied for maybe a day. Then when > the input frequency is disconnected the clock would continue to tell the > time. There are also many options for alarms. > > (4) Other displays such as fractional Julian Day number, fractional > Modified Julian Day number. sidereal time, or ??? > > I don't think there's enough memory for all of the above, probably only > one or two of them so I'm hoping to get some input on the priorities. > > Have Fun, > > Brooke Clarke > -- James Maynard Salem, Oregon, USA _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
