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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 |
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Drew's Clock (32x8 MUX LED display)
Started by ●November 7, 2004
Reply by ●November 12, 20042004-11-12
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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 |
