My 8-tube b7971 clock is powered by a RasPi; I posted a video several months ago before I built the case.
Using the WiringPi library, you can get decent GPIO speeds; I've measured about 2Mbits/sec when serialized completely by software. The problem is that the Pi runs Linux, so there are random time-slices the OS needs for housekeeping, so there will occasionally be gaps of a few milliseconds. For a clock, this shouldn't matter. This particular clock stores the segment data in a shift-register, and the Pi serializes the bit stream for 8 tubes * 16 bits/tube = 128 bits total. I update the time every second, and I've never observed any display glitches. Why use a RasPi ? Many reasons. - 10USD cost. OK, yeah, that doesn't include a 4GB micro-SD card or a power supply - Onboard WiFi, which means you can update software without opening-up or moving the clock. Just login and patch. - Full goodness of Linux, and the zillions of apps you can install - Remote access via VNC - Low power - No need to set the time - Automatically obtains it from your network (unless your network or internet service goes down) As long as you are aware of the pitfalls of a RasPi, you can easily work around them. In a few years I will find out if the OS causes the micro SD card to 'wear-out' , or if my clock gets hacked by a cyber terrorist. https://www.youtube.com/watch?v=OjQeW67viXw -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/0c50a801-a80f-4b3c-8d04-8590764b72bd%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
