Has anybody used OLED character displays in instruments?
This one
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looks cool. The outline is nice and small. It's rated at 150,000 hours at half brightness, which is 17 years. It will start to look ratty as often-used pixels dim next to seldom-used ones.
Any experience?
The full-color LCD types mostly seem to need high-data-rate, RGB, VGA-like drive with big wide flex cables, and would probably need a bunch of FPGA resources to drive.
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John Larkin Highland Technology, Inc
picosecond timing precision measurement
I used some character OLED displays, but they were discontinued. There are supposed to be moisture-related life problems with OLEDs, maybe they've solved them. Also .. screen savers on instruments, yuk.
You can get an ARM with an LCD controller. The frame buffer might be expensive in an FPGA.
I put an OLED in my alarm clock in 2007, it's been running 24/7 since then with no sign of degredation. But then again, I don't run the display at 100% brightness all the time (the clock has a photocell so it can dim at night) and it has a natural screen saver (the time changes over time ;)
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It's at 70k hours (ish) now, which IIRC was its rated lifetime.
Can't examine a datasheet right now, but what more could it need? Contrast potentiometer, EL backlight power and 3 voltages like an antique VFD? Even with the worst of all worlds, it's still not 20 pins.
Granted, the Hitachi "standard" for character displays is rather convoluted (I love how custom "letters" are bitmapped) , but it's not too hard to deal with and allows for quite a bit of flexibility when it comes to LCD or VFD use. The downside is those displays next to 4 buttons or whatever do give the "wow this shit is old" look for most interfaces.
Oddly enough it is *exactly* 20 pins. Check the data sheet and you'll see. Did you figure in the three pins to select the eight modes for the interface?
There's not a lot of artistic stuff you can do with a 7x5 matrix.
We are currently using a VF display that has 0.18" characters, and it looks great. The OLED chars are a bit bigger. I was thinking that an OLED would have similar sharp, bright pixels. I guess we'll get some and try it.
Pins 17..19 select between several interface options. Pin 20 is an extra ground.
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John Larkin Highland Technology, Inc
picosecond timing precision measurement
Whoa, that's waaayyy too big! Don't your instruments have small panels? I'm a fan of 0.96-inch OLED displays, with 128x64 pixels. We made an awesome font library for these. With top yellow band, $14:
On a sunny day (Tue, 08 Mar 2016 19:12:43 -0500) it happened DJ Delorie wrote in :
Nice box..
I have OLEDs now in 2 projects, here is one:
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this is GPS controlled, with position data logging, lipo battery. I notice no degradation after a year.
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The other one is a SWR meter, so hardly used, should last years.
Indeed run it at lowest brightness always, even then it is readable in sunlight. The main problem, IIRC, with OLEDs is in color displays where the colors age differently. LG makes a color OLED teefee where they use white OLED with color filters, to circumvent the problem, but that of course sucks (efficiency).
I have no experience with color OLEDs for teefee. It seems however Samsung makes nice AMOLED displays.
I have a Chinese cellphone that claims to have OLED, but it it looks like LCD to me (viewing angle), but maybe it has a white OLED backlight.
So, basically OLED is the future, I already decided not to use LCD anymore in projects. OLED = less power consumption, better viewing angle, maybe better colors.
I want to avoid a big hardware+software hassle generating video signals. All we really need is a 4x20 or better yet a 4x28 character display, but nobody makes a 4x28.
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John Larkin Highland Technology, Inc
lunatic fringe electronics
How does that work? How can you use a line as a select and a data bit at the same time? You mean a passive pull up/down overdriven by the controller at run time?
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