Simple Raspberry Pi Nixie Clock server, allowing outside scipt driven display
When I purchased my Nixie Clock and connected it to my Raspberry Pi, the firmware which was suggested by the vendor didn't have much capability and only allowed the clock to do one function, always initiated by running the driver and only from the command line. I wanted more.
I wanted a background server which could take commands from a Linux Pipe, thus allowing me to have a simple script which could anything I wanted and tell the display to change at any time, without having it stop and start again.
Since the clock is being driven from a Raspberry Pi running Linux, it already has NTP, which is synced to atomic clocks, so it doesn't need to rely on any internal clock chip. Hardware clock chips are notorious for drifting and using the Linux system time means the clock automatically adjusts for daylight savings, etc.
I have simplified the original "DisplayNixie.cpp" code, removing parts which are not needed and including comments to better describe what's happening. It now reads commands from stdin (which can be a pipe file) in a simple loop.
You can create a simple Linux pipe using the command:
% mkfifo pipe-name
where "pipe-name" is the name of your pipe file. I used "input".
You can then run the server with the command:
% NixieServer "clock" <input
You can feed the server commands using:
% echo "clock" >input
That's it! Simple! I like simple! Here are the list commands:
- clock - Display HH:MM:SS and keep it updated every second (normal clock display)
- leds R G B - Set the LEDs under the digits to the RGB values given
- dots L R - Turn on (1) or off (0) the dots between the digits
- settime - Set the time in the clock's clock chip (not really needed now)
- roulette - Run all digits through displays of all values very quickly for a few seconds
- setsystime - Set the clock's clock chip to agree with Linux system time (not needed)
Any other command which is not one of the above is expected to be a sequence of either digits or spaces. For example, my own script reads the inside and outside temperatures and displays them every few seconds with inside on the left and outside on the right, separated by blank digits (spaces).
You can blank the entire display (such as when you are going on vacation and don't need to place additional wear on the digits) by simply doing:
% echo " " >input
% dots 0 0 >input
% leds 0 0 0 >input
When you return, simply restart your script to drive the display.
I'm open to implementation of other commands, please send me email!
(The "roulette" function is pretty widely documented on the net as a way to reset the cathodes inside the tubes and keep them working well. Otherwise, the digits will become more and more dim over time. I run it at midnight!)