Well, i think i found a nice display for my preamp. It came from an OLD 12-digit calculator, and it's a LED based one (or perhaps neon? I can't tell), with three 8-segment displays encased in a big blob of crystal. The thing it's that it gives a BEAUTIFUL red, very dense and bright, almost looking like a VFD.
Now, each blob has 12 pins (8+1 segments, common for the three numbers and their respective power inputs), so, i'll need some driver for those. I wanted to steer clear of microcontrollers and such, does anyone knows of some kind of driver IC for these things? What do they need for implementation?
Now, each blob has 12 pins (8+1 segments, common for the three numbers and their respective power inputs), so, i'll need some driver for those. I wanted to steer clear of microcontrollers and such, does anyone knows of some kind of driver IC for these things? What do they need for implementation?
Don't know about the mysterious eighth segment (maybe it only glows in the fourth dimension) 
Lisandro, can you enlighten us a bit (pun time) ? Segments configuration ?
But have a look at the 74HC4511 (or CD4511), which is said to be able to drive LED, incandescent, LCD, fluorescent and gas discharge displays...
Hope this helps, and sorry for bad humor
Lisandro, can you enlighten us a bit (pun time) ? Segments configuration ?But have a look at the 74HC4511 (or CD4511), which is said to be able to drive LED, incandescent, LCD, fluorescent and gas discharge displays...
Hope this helps, and sorry for bad humor
I meant "7+1", damn! Yeah, the 8th segment is the decimal period (it's a calculator). This will go unused of course.
My problem is this lcds have common conections for each segment, and you "select" which one to light by conecting it's respective anode. This saves a lot of wiring, but you need a fast clock and the logic to swicth in between each display and light the apropiate segments fast enough. I was hoping that there was an easier solution, dunno, an ic which reads the segments to light from a small RAM and does the job for me.
On the other hand, if it's too much trouble i might end up with a micrcontroller; i have quite a lot of experience with assembler and stuff, but never built one of those (through i imagine it's no big deal). How much's a PIC16f84 f.ex (or similar)?
Yeah, the 8th segment is the decimal period (it's a calculator). This will go unused of course.My problem is this lcds have common conections for each segment, and you "select" which one to light by conecting it's respective anode. This saves a lot of wiring, but you need a fast clock and the logic to swicth in between each display and light the apropiate segments fast enough. I was hoping that there was an easier solution, dunno, an ic which reads the segments to light from a small RAM and does the job for me.
On the other hand, if it's too much trouble i might end up with a micrcontroller; i have quite a lot of experience with assembler and stuff, but never built one of those (through i imagine it's no big deal). How much's a PIC16f84 f.ex (or similar)?
Well, right now i'm rebuilding my power amp. I already have the digital volume control thought out, and Maxim were kind enough to send me a couple of their led driver ICs (namely, MAX7218 and MAX7221) as free samples, which are a very neat way of handling these displays. They need a serial input though, so it's pretty much assured i'll be needing to use a uController.
Is either that, or using discrete logic and ditching that beautiful display
Is either that, or using discrete logic and ditching that beautiful display
Actually, I'd like to use a 0-199 disp, with volume showing from 0 to 100, but 8bit is normally from 0-255.
Also, I'd like to show the volume for 3 secs when it's being moved, if not, I'll show eg. "TAPE V1" OR " CD V2"(V is for Video). It would be possible with some AND & OR gates, 555 timers, hex inverters and tons of diodes.(+Space and $$$)
Also, I'd like to show the volume for 3 secs when it's being moved, if not, I'll show eg. "TAPE V1" OR " CD V2"(V is for Video). It would be possible with some AND & OR gates, 555 timers, hex inverters and tons of diodes.(+Space and $$$)
Thing is, the moment you add up more than 5 or 6 discrete logic ICs, you're better off using an uC anyway, both for space, simplicty and price. I orignally was planning to use a counter for the volume control and assorted digital gates for the input switching, but if i'm adding a display i might as well go the extra mile and do it with a uC.
Also these 7 seg are not cheap.
I can get a 2x40 LCD disp. for 10CDN$ but characters are really small. I guess I'll try the µcon way but I don't know how to program and what display I would use. Maybe a 1x8 VFD? Or a 10seg LED meter for VOL, with LEDs and transparents for source, or just NOT show the volume and only source with diodes.
Also, this might be interesting, a project on 8052.com (Using the 8052 processor, duh!)shows some graphics in monochrome on a TV. The only problem is that it would need a TV showing only this.
I can get a 2x40 LCD disp. for 10CDN$ but characters are really small. I guess I'll try the µcon way but I don't know how to program and what display I would use. Maybe a 1x8 VFD? Or a 10seg LED meter for VOL, with LEDs and transparents for source, or just NOT show the volume and only source with diodes.
Also, this might be interesting, a project on 8052.com (Using the 8052 processor, duh!)shows some graphics in monochrome on a TV. The only problem is that it would need a TV showing only this.
So with this you use some BCD to 7-seg controlled by a µC(Can only do numbers?), or a µC directly controlling it?
Note: the Z80 can be a good processor too, you can use a ROM, or any other source and then you're done(These are so robust that they can have the quartz replaced by a switch, and need no RAM, or anything else).
Some Z80 projects with some led matrix displays:
http://members.lycos.co.uk/leeedavison/z80/
http://www.z80.info/z80_mp.htm
http://z80.info/
Note: the Z80 can be a good processor too, you can use a ROM, or any other source and then you're done(These are so robust that they can have the quartz replaced by a switch, and need no RAM, or anything else).
Some Z80 projects with some led matrix displays:
http://members.lycos.co.uk/leeedavison/z80/
http://www.z80.info/z80_mp.htm
http://z80.info/
http://www.specs.de/users/danni/appl/hard/max7219/max7219.htm
has one which can display others than numbers(Uses a Maxim + 8051 CPU) using the CPU to program them.
has one which can display others than numbers(Uses a Maxim + 8051 CPU) using the CPU to program them.
The 7-seg in my calculator are actually VFDs (http://hem.passagen.se/communication/vfd.html)
Would need a lot of I/Os to drive(19).
Would need a lot of I/Os to drive(19).
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