Post by thread:[PIC:] Dot Matix displays

Hi Guys I looking for a dot-matrix display to show some simple graphics in a painel. I need something like an 8x8 led display dot matrix, I found some from Agilent (HDSP-S8xG) and others, which meet my drawing criteria, but my problem is the high current these displays consume (more than 1A). I thinking about using a LCD small display, but I never worked with anyone. Did anybody use one of these with a PIC? Is it possible (memory problems perhaps)? I f anyone has some links which has good information abou this, please point me. Thanks, Rodrigo -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email spam_OUTlistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

> I looking for a dot-matrix display to show some simple graphics in a > painel. I need something like an 8x8 led display dot matrix, I found > some from Agilent (HDSP-S8xG) and others, which meet my drawing > criteria, but my problem is the high current these displays consume > (more than 1A). What's the problem? There is plenty of choice in dot-matrix LED displays. I sell one that might be interesting: http://www.voti.nl/shop/p/DISP-11.html > I thinking about using a LCD small display, but I never worked with > anyone. Did anybody use one of these with a PIC? Is it possible > (memory problems perhaps)? What do you want, LED or LCD? And what number of pixels? Memory is only a problem when you want to build an in-memory image of the display, avoid that. > I f anyone has some links which has good information abou this, please > point me. There is plenty of good info around (bad info too), but you must be more specific in what you ask :) Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: http://www.voti.nl consultancy, development, PICmicro products -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam@spam@mitvma.mit.edu with SET PICList DIGEST in the body

Wouter van Ooijen <wouterKILLspamVOTI.NL> writes: >> I looking for a dot-matrix display to show some simple graphics in a >> painel. I need something like an 8x8 led display dot matrix, I found >> some from Agilent (HDSP-S8xG) and others, which meet my drawing >> criteria, but my problem is the high current these displays consume >> (more than 1A). > > What's the problem? There is plenty of choice in dot-matrix LED > displays. I sell one that might be interesting: > http://www.voti.nl/shop/p/DISP-11.html The problem is the high current, I will use it in an electrical vehicle, which uses a battery as energy source. As I understood, each led consumes about 20mA, with all leds on I will consume in a 8x8 dysplay something about 1.3A. >>> I thinking about using a LCD small display, but I never worked with >> anyone. Did anybody use one of these with a PIC? Is it possible >> (memory problems perhaps)? > > What do you want, LED or LCD? And what number of pixels? Memory is only > a problem when you want to build an in-memory image of the display, > avoid that. Because of the high current with the led displays, I am trying to find an alternative with a LCD, but I don't know anything about it. It would be enough to have and LCD with 64 pixels (but I don't even know if such a things exists), just like the LED dot-matrix displays. > > There is plenty of good info around (bad info too), but you must be more > specific in what you ask :) I think I only found the bad info, of course it is because I don't know the right keywords. []s Rodrigo -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam.....mitvma.mit.edu with SET PICList DIGEST in the body

> Wouter van Ooijen <EraseMEwouterspam_OUTTakeThisOuTVOTI.NL> writes: > > >> I looking for a dot-matrix display to show some simple graphics in a > >> painel. I need something like an 8x8 led display dot matrix, I found > >> some from Agilent (HDSP-S8xG) and others, which meet my drawing > >> criteria, but my problem is the high current these displays consume > >> (more than 1A). > > > > What's the problem? There is plenty of choice in dot-matrix LED > > displays. I sell one that might be interesting: > > http://www.voti.nl/shop/p/DISP-11.html > > The problem is the high current, I will use it in an electrical > vehicle, which uses a battery as energy source. As I understood, each > led consumes about 20mA, with all leds on I will consume in a 8x8 > dysplay something about 1.3A. > Not really, the general idea with matrix displays is that they're scanned - that is only one row (or column - your choice) is on at one time. So worst case scenario is a yellow column, 14 leds (7 red and 7 green to make yellow) 14 x 20mA = 280mA. Though that may still be more than you want. Wouter - Those look like the same ones I just bought from electronics goldmine http://sales.goldmine-elec.com/prodinfo.asp?prodid=9068 Just showed up yesterday, funny how things work out sometimes. Any chance someone's created them as a library part in Eagle? -Denny -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listservspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body

Rodrigo Real wrote : > The problem is the high current, I will use it in an electrical > vehicle, which uses a battery as energy source. As I understood, each > led consumes about 20mA, with all leds on I will consume in a 8x8 > dysplay something about 1.3A. Hi. Depending on the environment (inside, outside, sunshine and so on) you might not have to use the full 20mA/LED. At least for inside use, a few mA's/LED might be enough. But if we are talking about something like a "golf car" (or whatever those things you can se G W Bush driving around in are called), it might be another story... Regards, Jan-Erik. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email @spam@listservKILLspammitvma.mit.edu with SET PICList DIGEST in the body

> The problem is the high current, I will use it in an electrical > vehicle, which uses a battery as energy source. As I understood, each > led consumes about 20mA, with all leds on I will consume in a 8x8 > dysplay something about 1.3A. 1. How often will you turn all LEDs on? A typical letter or digit has only a few LEDs on. 2. You might consider dimming the total display depending in the number of LEDs on (sort of constant total brightness). 3. Check for high-efficiency versions, or create your own from 64 high-efficiency (2mA) LEDs. Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: http://www.voti.nl consultancy, development, PICmicro products -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email KILLspamlistservKILLspammitvma.mit.edu with SET PICList DIGEST in the body

----- Original Message ----- From: "Rodrigo Real" <RemoveMErodrigoTakeThisOuTFREEDOM.IND.BR> Subject: Re: [PIC:] Dot Matix displays > >>> I thinking about using a LCD small display, but I never worked with > >> anyone. Did anybody use one of these with a PIC? Is it possible > >> (memory problems perhaps)? If you are looking for displaying one of a relatively few symbols, then an LCD character module may well be the ticket. These things are low current and simple to program for. Most (maybe all) have about a dozen cells for user-programmed characters, in addition to (typically) two character sets. If you don't need the backlight, they are typically very low current. If you need it backlit, however, the backlight can be quite power hungry - pretty much depending on the area of the display and the brightness you want, the backlight can draw almost an amp. If all you are looking for is one character, however, LCD modules with very few characters are pretty hard to come by. Dot matrix LCDs are, of course, available but they are relatively expensive. --McD -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email spamBeGonelistservspamBeGonemitvma.mit.edu with SET PICList DIGEST in the body

> If you are looking for displaying one of a relatively few symbols, then an > LCD character module may well be the ticket. These things are low current > and simple to program for. Most (maybe all) have about a dozen cells for > user-programmed characters, in addition to (typically) two character sets. > What about an LCD display that displays a time formated output, and nothing else, and is very small. Something like xx:xx - and nothing else. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email TakeThisOuTlistservEraseMEspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body

Denny Esterline <RemoveMEfirmwareTakeThisOuTTDS.NET> writes: {Quote hidden}>> Wouter van Ooijen <wouterEraseME.....VOTI.NL> writes: >> >> >> I looking for a dot-matrix display to show some simple graphics in a >> >> painel. I need something like an 8x8 led display dot matrix, I found >> >> some from Agilent (HDSP-S8xG) and others, which meet my drawing >> >> criteria, but my problem is the high current these displays consume >> >> (more than 1A). >> > >> > What's the problem? There is plenty of choice in dot-matrix LED >> > displays. I sell one that might be interesting: >> > http://www.voti.nl/shop/p/DISP-11.html >> >> The problem is the high current, I will use it in an electrical >> vehicle, which uses a battery as energy source. As I understood, each >> led consumes about 20mA, with all leds on I will consume in a 8x8 >> dysplay something about 1.3A. >> > > Not really, the general idea with matrix displays is that they're scanned - > that is only one row (or column - your choice) is on at one time. So worst > case scenario is a yellow column, 14 leds (7 red and 7 green to make > yellow) 14 x 20mA = 280mA. You are right, I was stupid... > > Though that may still be more than you want. > Well, I could live with that, but I think that maybe the LCD could give me a better result. I am happier now... Thanks a lot, Rodrigo -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email EraseMElistservmitvma.mit.edu with SET PICList DIGEST in the body

Jan-Erik Soderholm <RemoveMEjan-erik.soderholmEraseMEEraseMETELIA.COM> writes: > Rodrigo Real wrote : > >> The problem is the high current, I will use it in an electrical >> vehicle, which uses a battery as energy source. As I understood, each >> led consumes about 20mA, with all leds on I will consume in a 8x8 >> dysplay something about 1.3A. > > Hi. > Depending on the environment (inside, outside, sunshine and so on) > you might not have to use the full 20mA/LED. At least for inside > use, a few mA's/LED might be enough. If we go to the LEDs option, We could dimm it, as Wouter said, using a LDR. Our vehicles work inside and outside, depending on the application. Rodrigo -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email RemoveMElistservspam_OUTKILLspammitvma.mit.edu with SET PICList DIGEST in the body

>Because of the high current with the led displays, I am trying to >find an alternative with a LCD, but I don't know anything about it. > >It would be enough to have and LCD with 64 pixels (but I don't even >know if such a things exists), just like the LED dot-matrix displays. It is not clear to me how many characters you want, but I think you are wanting only one large character. In this case I would look at using the LCD off a mobile phone as a single large character display. If you need backlighting, then put all the leds that light it in series, as I am sure your electric vehicle will have more than enough voltage available to do this. However you may have an alternative when using an LED display, Use a switching regulator to drop the voltage from the battery to something only slightly greater than the LED requires. You will find the current draw from the battery drops considerably from the 1.3A you describe, and I doubt that you would actually reach 1.3A anyway for any meaningful char on the display. -- http://www.piclist.com hint: To leave the PICList EraseMEpiclist-unsubscribe-requestspamspamBeGonemitvma.mit.edu

pic microcontroller discussion list <> wrote: > I looking for a dot-matrix display to show some simple graphics in a > painel. Have you looked at LCD switches? http://www.screenkeys.com/screenkeys/s1.html It's particularly useful if you need a switch too! The downside is that there are no character generator routines built in, you basically send it a bitmap for display. I've got one of them running from a 16f627, with several words stored in ROM from which required messages can be displayed, you could do the same with digits or whatever. Available resolutions are from 24x16 to 64x32, and there is an RGB backlight version. They're a bit pricey, but the biggest disadvantages are that they do not have single hole mounting (PCB only) so need a square panel hole. The interface was easy to use and well documented. Nigel -- -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestKILLspammitvma.mit.edu

Nigel Orr <nigelSTOPspamspam_OUTAXONINSTRUMENTS.CO.UK> writes: Hi Nigel {Quote hidden}> pic microcontroller discussion list <> wrote: >> I looking for a dot-matrix display to show some simple graphics in a >> painel. > > Have you looked at LCD switches? > http://www.screenkeys.com/screenkeys/s1.html > > It's particularly useful if you need a switch too! The downside is that > there are no character generator routines built in, you basically send it a > bitmap for display. I've got one of them running from a 16f627, with > several words stored in ROM from which required messages can be displayed, > you could do the same with digits or whatever. Available resolutions are > from 24x16 to 64x32, and there is an RGB backlight version. These seems to fit exactly in what I was thinking on LCDs. I will keep evaluating the LCD and LED alternatives. Thanks a lot for this tip, I was thinking about something exactly like this, except for the switch, but no problem with this, maybe the switch will be useful. Sometimes it is difficult to buy this kind of electronics in Brasil, so I am thinking about that too. Thanks again for all of you who are trying to help. Rodrigo -- http://www.piclist.com hint: To leave the PICList spamBeGonepiclist-unsubscribe-requestSTOPspamEraseMEmitvma.mit.edu