On 18/05/2015 9:41 AM, IVP wrote: >> Is this doable with a PIC or ATXMEGA chip? > Hi David > > The refresh rate will be too fast (ie a very low duty cycle per column) > for a really bright display by direct drive. You can use latches to hold > the data. I've serviced displays which were split into halves or quarters > with a micro for each. > > This one I made manages a 200Hz refresh rate quite comfortably > even with a modestly slow PIC. There's plenty of time for graphics > or effects, more so if a newer, faster PIC was used > > http://home.clear.net.nz/pages/joecolquitt/message.html > > Driver ICs (eg ULN200x) could be used instead of transistors Hi Joe, These displays have latches for the pairs of rows built in. They're=20 part way between bare LEDs and a fully latched unit. Here's a page that explains it better than I can directly.=20 http://docs.pixelmatix.com/SmartMatrix/ David... --=20 ___________________________________________ David Duffy Audio Visual Devices P/L Unit 8, 10 Hook St, Capalaba 4157 Australia Ph: +61 7 38235717 Fax: +61 7 38234717 Our Web Site: www.audiovisualdevices.com.au ___________________________________________ --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .