The relevent parts of Drew's project have now been uploaded to http://www.16f877.org/drew/clock Regards Sergio Masci ----- Original Message ----- From: sergio masci To: <> Sent: Sunday, November 07, 2004 5:48 PM Subject: [piclist] Drew's Clock (32x8 MUX LED display) > > Hi All, > > Drew produced a digital clock for his college project. > > It uses a 32x8 multiplex array of LEDs (256 in total) > > The display is bit mapped and you could actually use the project as a > scrolling message board. > > All the components (except the matrix boards) were bought from "Van Ooijen > Technische Informatica: www.voti.nl " in Holland at a very good price. My > gratitude to Wouter for his excellent service and providing everything so > quickly. The LEDs are standard 3mm "surplus" (not super bright) which makes > them cheap. The display can be read easily in normal room lighting > conditions. > > The picture at http://www.xcprod.com/titan/XCSB/CONTRIB/drew-clock-002.jpg > shows the circuit built on two matrix boards mounted at 90 degrees to each > other. This arrangement simplifies connecting the LED matrix to the rest of > the circuit. > > It uses 4 shift registers and 4 buffers to drive the 32 column selects (this > can easily be extended to give a much wider display) and a single buffer for > the row selects. > > The clock uses 2 switches to allow the hours and minutes to be set. It could > easily be interfaced to a PC using a MAX232 chip and some capacitors (see > http://www.xcprod.com/titan/XCSB/CONTRIB for details about putting such an > interface together). > > The processor is a 16F876A. > > The program to drive this project was written using XCSB and the source code > is provided at http://www.xcprod.com/titan/XCSB/CONTRIB/drew-clock-015.bas > > He does have a circuit diagram for this project and will publish it once he > gets it back from the college. > > Regards > Sergio Masci |