- Mon Aug 29, 2011 12:41 pm
#132650
I got myself a portable synthesizer with a non-backlit LCD display and I'd like to fit a light to it... So I'm trying to figure out what my options are.
I looked into swapping out the LCD for a backlit type - but the display is a discontinued Optrex display... I don't know if there's a pin-compatible replacement out there that has a backlight. It's a serial display (meaning it has a clocked serial line and it updates one pixel on each serial clock - not like the "serial displays" on Sparkfun, which take commands over an RS-232 connection) - it might be possible to program a microcontroller to read the display data and push it to another display module, but a lot depends on how fast the synthesizer is actually driving the display. (The spec'ed top speed for the display is around 250ns per pixel - 4MHz pixel rate - which means to reliably get both the rising and falling transitions of the clock line, I'd need to sample at 16MHz... I think an AVR running at 16MHz can do this, but I can't remember. I know 16F-series PICs would have to be run at a higher clock rate in order to sample at 16MHz...)
I've also heard of adding a backlight by removing the reflective backing of the display. That's a bit scary, of course - if the mod didn't work out, I guess the display, and therefore the synth, would be ruined. And if the backlight is off, would I be able to read the display? (Maybe I can find a cheap LCD in my stash and test this out...)
Then there's less-invasive methods, like side-lighting or front-lighting. I think I'd be happy with these methods if I can get them to work nicely... There's a couple open points on the sides of the display through which I could shine in some LED light - but it'd be better if I could get light in through multiple points, get a better distribution over the surface of the display. But I don't know what it'd take to actually do that... Cutting additional holes in the metal frame of the LCD? I'm not even sure what that would take... Then there's front-lighting, which is kind of the same deal but with a light guide. I did this with my Game Boy Advance long ago using the old Afterburner kit (good times! Though I screwed up the installation the second time I did it...) - I don't know if there's physical space in there for the addition of a light-guide, or even where one would get a light guide.
An EL strip behind the display would probably be ideal for a nice uniform glow, though I am a bit wary of the possibility of the inverter generating RFI in there and messing up the sound. (And there's the question of what happens to the display if I remove the reflective layer...) LED might be less ideal from a visibility standpoint, but easier to implement...
Hm, I don't know. Thoughts?
I looked into swapping out the LCD for a backlit type - but the display is a discontinued Optrex display... I don't know if there's a pin-compatible replacement out there that has a backlight. It's a serial display (meaning it has a clocked serial line and it updates one pixel on each serial clock - not like the "serial displays" on Sparkfun, which take commands over an RS-232 connection) - it might be possible to program a microcontroller to read the display data and push it to another display module, but a lot depends on how fast the synthesizer is actually driving the display. (The spec'ed top speed for the display is around 250ns per pixel - 4MHz pixel rate - which means to reliably get both the rising and falling transitions of the clock line, I'd need to sample at 16MHz... I think an AVR running at 16MHz can do this, but I can't remember. I know 16F-series PICs would have to be run at a higher clock rate in order to sample at 16MHz...)
I've also heard of adding a backlight by removing the reflective backing of the display. That's a bit scary, of course - if the mod didn't work out, I guess the display, and therefore the synth, would be ruined. And if the backlight is off, would I be able to read the display? (Maybe I can find a cheap LCD in my stash and test this out...)
Then there's less-invasive methods, like side-lighting or front-lighting. I think I'd be happy with these methods if I can get them to work nicely... There's a couple open points on the sides of the display through which I could shine in some LED light - but it'd be better if I could get light in through multiple points, get a better distribution over the surface of the display. But I don't know what it'd take to actually do that... Cutting additional holes in the metal frame of the LCD? I'm not even sure what that would take... Then there's front-lighting, which is kind of the same deal but with a light guide. I did this with my Game Boy Advance long ago using the old Afterburner kit (good times! Though I screwed up the installation the second time I did it...) - I don't know if there's physical space in there for the addition of a light-guide, or even where one would get a light guide.
An EL strip behind the display would probably be ideal for a nice uniform glow, though I am a bit wary of the possibility of the inverter generating RFI in there and messing up the sound. (And there's the question of what happens to the display if I remove the reflective layer...) LED might be less ideal from a visibility standpoint, but easier to implement...
Hm, I don't know. Thoughts?
---GEC