Yes, it does get complex. I saw an amazing display at the ESPN bar in Orlando recently that uses LEDs that can generate red, green and blue, and consequently it could do red, orange, yellow, green,blue and violet. Very slick. If they are multi-terminal devices you need three shift registers and cathode drivers, but still only 8 row drivers. If you are using two-terminal red/green LEDs then the driver circuitry is complex because it has to be able to switch a bipolar signal across the LEDs. For yellow, you'd need to switch the signal rapidly, as well. So I think multi-terminal devices would be far simpler to use. Expensive, though. > ---------- > From: **NERI**[SMTP:nllosat@MAIL.COSAPIDATA.COM.PE] > Reply To: pic microcontroller discussion list > Sent: Tuesday, December 02, 1997 3:37 AM > To: PICLIST@MITVMA.MIT.EDU > Subject: Re: Scoreboard [OT] > > Andy: > Your discussion of the multiplexing of columns in a large scoreboard > is understandable. I use 16 of the 7x5 red displays in a scoreboard > I've designed. But do you know a method in which you do the same thing > with 7x5 displays with bicolor LEDs? ( Red, Green and Yellow also) .I > think the hardware would become a lot more complicated. > Any suggestions would be appreciated. > -- Neri. > Κ > > From: Michael Coop (pjm) < mcoop@POP.JARING.MY > > > To: PICLIST@MITVMA.MIT.EDU > Date: Lunes, Diciembre 01, 1997 1:21 AM > Subject: Re: Scoreboard [OT] > > > > Troy, > > Try looking at display drivers for alphanumeric LED displays - this > should > give you a good idea where to start. > > The most common displays are arranged as a 5 columns x7 rows matrix, > and > there are chips designed to specifically drive these displays, or for > a > more economical approach to large displays, you may consider treating > the > display as 'blocks' of perhaps 8x8 pixels. > > Then, you can address the columns directly, or use a shift register to > 'walk' along the columns one at a time, while you send 8 bits at a > time to > turn the lamps on in each column as desired. > > Of course you need to keep in mind the refresh rate and power > available for > your particular application. > > Regards > MC > > On Monday, December 01, 1997 3:35 AM, Troy Powledge [SMTP: > tpow@eramp.net ] > wrote: > > Are we talking about the type of score boards that you see outside > of > banks that display time and temp with light bulbs for pixels? If so I > would > like to know how all of the individual pixels are controlled. They > have to > be multiplexed some how. Any information about the system would be > appreciated. > > Processor? > > Multiplex scheme? > > Software? > > Thanks, > > Troy Powledge > > TCo. Systems > > > > -----Original Message----- > > From: Andy Tucker [SMTP: rtucker@SCCI.NET > ] > > Sent: Friday, November 21, 1997 7:42 AM > > To:ΚΚ PICLIST@MITVMA.MIT.EDU > > Subject:ΚΚΚΚΚ Scoreboard > > > > I am looking for the person wanting some information on scoreboards > > I have located someone who maintanes the sysyems in our county and > > he said he would like to help. > > > > Please E-mail me at rtucker@scci.net > > > > Andy Tucker > > >