I heard of a guy who is sort doing the reverse - he is taking the four levels of neon dot intensity found on DMD displays and mapping these to different colours on an RGB LED matrix, to get automatic pseudo-colouring. I bet he knows how the drivers work inside out.
As the original displays get older and fail, more people are turning to the colour LED displays, where someone has laboriously mapped every animation frame in colours. Not cheap, just shy of $400 for one of these. John S On 31 Dec 2015, at 08:00, Tristan wrote: > I started development of a clock using some similar displays (except 256x64 > pixels). > > https://sites.google.com/site/tristansideas/electronics/pinball-display-clock > > Sadly a lack of time has prevented me from finishing the project so far. They > can pretty much be driven from the SPI peripheral of most micros. I used an > MSP430 for testing. This allowed each row of display data to be shifted in > using one of the DMA channels with minimal interrupt/CPU usage just to latch > each row keep track of the number of rows. I was able to achieve 4 levels of > grey pretty easily. The chip on the dev board I used didn't have RAM to hold > the entire frame buffer so I was using an external SPI SRAM (also DMA > driven). This was not intended to be the long term design and I would use a > part with enough RAM on board. > > I've been thinking of driving them from a BeagleBone Black. Simply because > the PRU's available would be capable of doing the real time processing > required. Trammel Hudson used this method to drive a Mac-SE display and only > minimal changes would be required to run a DMD. > > https://trmm.net/Mac-SE_video > > That's not to discourage the use of an FPGA. Even without one I was able to > exceed the 200Hz maximum using the MSP430 (they still seem to work at > > 200Hz). These displays do use a fair amount of power. They can get warm. They > also have a tendency to produce a high pitched whine when operating. They did > run in pinball machines in arcades pretty much non-stop but they do wear out > eventually. There are LED based replacements available now but that lacks a > certain something that you can only get from neon. -- 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 [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/CDA6504C-6EFF-48BD-8458-44C09A6507DF%40jsdesign.co.uk. For more options, visit https://groups.google.com/d/optout.
