5:38 Funny case in fact about LCD's being sluggish when cold, my mom's car has an LCD displaying (among other info) the outside temperature. When it gets near or below freezing, the temperature indication will blink to alert you to that. Except that precisely because it is cold, the blinking will be almost unnoticeable since the indicator hardly fades before it comes back on again.
There is a video about the Gameboy DMG LCD. Strobe light or a fast camera shutter show that it flickers faster than the human eye can see. Do Gameboys fail in winter?
@@ArneChristianRosenfeldt They won't fail just from a low temperature. The cold will negatively affect the screen's responsiveness, causing what is called ghosting. You will see an after image when something disappears from the screen, or a fading trail behind something moving across the screen. But this effect disappears when the display is warmed up again.
@@MicraHakkinen good thing that the liquid is not water and can’t break stuff as it freezes. I was just wondering: I know the ghost of the cursor on Ti Z80 based calculators, but there is no ghost on Gameboy.
Well, you actually can drive a simple LCD display with common microcontroller GPIO if you need. Just drive the common electrode and inactive segments low while driving active segments high for 100 ms then switch everything by inverting the output: high on common and inactive and low on active segments for another 100 ms. That way you generate AC square waveform with no DC component relative to the common LCD electrode.
@@gauravsingh84for starters, a lot of these don’t have one common electrode, but a matrix of rows and columns. At least logical, even if not laid out as such. Then if you pay enough you get a ton of GPIO . Enough for segment LCDs. Not enough for Gameboy DMG.
I sometimes used "simple" LCDs directly connected to a micro. You can do that without burning out the display by generating the AC in software. Connect both the common and the segments to GPIOs. Set the common to high and the segment to low and reverse that every 1/100s using an interrupt. To turn off a segment set its GPIO to the same logic level as the common (so no voltage across that segment, even if both the common and the segment change level every 1/100s). With clever programming you can even drive multi common displays this way.
I still find it absolutely amazing that LCDs are in everything from cheap calculators to 100" 4K Dolby Vision enabled TVs. You don't get that kind of scaling from any other display technology.
I know it's pretty much common sense that we're surrounded by plastic. But I had the same sense of sort of awe (and horror) when I looked around my house and struggled to find anything that didn't have plastic of some sort in it. The only things really were things like seashells I collected, and maybe my dry wall? Oh and I guess my clothes... well except for the buttons and probably tags. It's mind boggling to realize I'm not just surrounded by the stuff, it's in literally EVERYTHING I own. I feel like this is gonna be one of those things we look back on in the future and say "wtf were they thinking?" Like we do with victorian practices. Like using tobacco smoke enemas to cure drowning. Seriously, they actually had rescue kits to do this set up on the Thames. Or using benzene as an aftershave, when we now know it causes leukemia. And the classic opium and cannabis tincture for your baby when they won't sleep. Probably because they're addicted to opium. Not to mention the horrible adulterants that were added to food. There was a book of advice for housewives that suggested adding borax to sour milk to mask the sour taste so you can keep drinking it longer. Wasn't Victorian England so magical? lol
This is exactly what I expect from your channel. A way to learn electronics, combined with your experience, not seen in any other channel. A bit of stuff for the beginner, a bit of new stuff for the experiences. Great subject!
As far as driving them, can't you put them between 2 output pins of a micro? And have the pins alternate between 1 and 0 in opposite phase? That's AC. Actually I tried that with an Arduino and didn't get anything, wasn't sure if I'd got the frequency right. That said I didn't know the pinout, just a random scrap glass module, tried running wires between contacts at random, and guessing the frequency, between about 10 and 100Hz.
Thanks a lot for your video about displays. I am just disappointed that most displays used in DIY projects are simple few segments LCD or up to 640x480 displays. I would however like to use smartphone displays having much higher resolutions for displaying good quality images. those displays are mainly driven by the MIPI standard. I am still looking in ways to interface those displays with simple microcontrollers and by using an intermediate graphic driver having a frame buffer. The microcontroller would just fill the frame buffer (for picture display , low refreshment would be ok) and the graphic driver would control the "smartphone" quality display accordingly. Maybe this could be an interesting subject for a future video.
It's actually possible to drive the through-hole type (the simplest) LCDs using GPIO output pins by reversing the drive polarity in a loop (I used a 4Hz timer). I used a TI MSP430F2272 micro-controller that had all the required GPIOs.
I was thinking the same when I paused the video to have a closer look at the display. The uSupply has been a long time coming. I'm looking forward to seeing that project becoming available as something we can buy or as a kit we can build.
Cool. I hope I can fix my Viewsonic 17" LCD which flicker every 15 seconds after 30 minutes of being ON. I replaced all capacitors but it still flickers. Where should I check next? Also the OLED of my Wacom Intuos won't turn ON (it used to display a display but some lines are missing), what should I check on that Wacom's OLED section/module? Thank you. God bless, Rev. 21:4
Those bare LCDs are a pain to drive without a driver chip. I find it much easier to salvage a VFD from something, than to get a random LCD working. I do like using the old 84x48 Nokia LCDs in projects though, they are dirt cheap and simple to drive over SPI.
wait... i noticed that i can view the screen of my 3ds just fine in direct sun and indoors so i think it uses a transflective display. i dont know how they were able to get the 3d technology to work with this sort of display though
Third time's the charm, eh Dave? That really small character LCD is actually used in one product I own, and one I want to own. the TNS-HFC5 Famicom cartridge and OSSC line doubler both use it in its I2C form as the AQM0802 (8 x 2) A or GW (backlight). It's a pretty nice little screen.
This big single digit LCD (or a similar one) was used in a clock circuit published in one of these electronic paper magazines. I think it was elektor. It was 10+ years ago. Point is: Since they are static they just used 74HC595 or 4094 (can't remember exactly) to drive all the segments. The common pins were tied together and driven by something else. The microcontroller had to do the AC switching of course. The display is so big that it was no problem to hide the DIL ICs underneath it.
Is there a trick to refitting the zebra strip to those lcd's? I remember I pulled one apart and reassembled and it never worked properly again. Seemed to need to put pressure on it to get it to work after that.
If you don't need anything huge, and especially for hobbyist use, it's just cheapest and fastest to use modules with built in driver and memory, like HD44780-compatible modules (usually with 5mm letters, but there's also a huge 20x4 display with 8mm letters that i've seen), Nokia LCD clones with SPI, monochrome graphic LCDs with ST7565 or something like that. The go-to is certainly HD44780, the smaller ones cost pretty much nothing and you can just keep a bunch.
Siana Gearz Thanks for sharing. Believe it or not there are even some rarer 1602 character LCD's that come in an "XL" variety. They are larger than the 2004's, and run on the same HD44780 driver. I've been learning about the LCD's associated with the OSHW AVR Transistor Tester project recently. (HD44780 (16×2 Character), ST7036 (DOGM), PCF8812 (Nokia 3410), PCF8814 (Nokia 1100), PCD8544 (Nokia 3310/5110), SSD1306 (OLED), NT7108/KS0108 (Graphic), ST7565 (Graphic), LCD2004, (20×4 Character), ST7735 (TFT), ILI9341 (TFT), ILI9342 (TFT), ST7920 (Graphic)) I have a little more than half of those on my bench. The cheap Chinese graphics displays are not very commonly used on the more professional EE projects I've seen. I want to know if there are other basic options that do not cost a fortune. Character displays are great for cheap functionality, but they are a bit dated tech in my opinion. I haven't tried the integrated uC options like the Nextion displays (yet). I'm mostly I interested in discovering the respectable EE world outside of eBay/AliEx/affiliate link content creators ;) -Jake
You could perhaps get more success from SerpantZA, though I doubt it - he figured out where youtube get their Silver Play Button awards manufactured locally to him in China and tried to get a factory tour even turning up at the factory gate ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-4EL4xBxc5IA.html
I have the Display'o'tron Hat for the RasPi, from what I understand this LCD is a COG type, already mounted on a PCB board for convenience. It uses the serial i2c bus on the GPIO but i think it supports other modes too, i'd love to learn how to interface with this directly instead of using the python library.
19:02 isn't the blue one(@ 10:38) transmissive? at least I thought that since the ones like that "blue backlight lcd 16x2 whatever" seem to be unusable unless you use the backlight
One thing I have always been curious about with both LCD and LED 7-segment number displays: why do so few of them have the "bottomless" 9s, while most use the bottom segment with their 9s? I think the bottomless 9s look cooler (although I can see why you'd avoid the topless 6s, as they might be mistaken for a b, or vice versa), and it seems they would save power?
This is the 2nd video link "How to drive LCD" ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ZP0KxZl5N2o.html and 3rd "Custom LCD design" ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ZYvxgl-9tNM.html
I have a old cog screen lcd, with out of production ic driver, with específic pin descripition layout. Today, i see many ic drivers compatible with the same resolution (128*64) but not with 36 pin and same descripition interface. There is another way to solve this problem without buy a single one custom screen?! Emulator, Arduíno, any help?! I just want repair one an RC Radio, and learn something.
Can you do a video on how to change the polarizer film? My battery charger has been used for 10 years and the LCD screen has faded. It is using flat flex that glue onto the board, and can't be removed, I'm afraid damage the flat flex while changing the polarizer film and leave it as it is while still using as it is still working. Thank you
The LCD display is the same colour as the table under it, if it wasn't for the silver connectors it would look like the display as appearing on the table by magik.
Great. This is what the old Dave did so well. Yes Dave, you stopped doing what you were good at. Your viewers are not the problem. Please do more, not less, teaching rather than ranting.
Thanks for that video! What would be also very interesting to see a comparision between LCD and TFT. How is the readability between LCD and TFT under daylight conditions? Is an LCD still the best readable display for outdoor products? Lots of motorbikes are switching to TFT-Cockpits but I'm not sure if these are transflective TFTs?
Technically, TFT's *are* LCD's, but unlike LCD's, they *require* a backlight. TFT = Thin Film Transistor, where each pixel (or do they have them with segments too?) has an associated transistor that turns it on or off, thereby blocking the light coming from the backlight, or letting it through.
I doubt. The transistor layer would damp the incomming light so much that it would be practically unusefull. You need to take into account that the transistor layer is located on the inner side of the rear glass plate (where the LC liquid is). The reflector is placed outside. The light must pass the transistor layer twice.
Where can one get a transparent (very clear) or "transmissive" LCD? Seems like they're not very wide-spread. Just a couple of videos on youtube that show off a couple of products in Japanese.
Hi Dave, I have seen some see through LCDs on AliExpress. I am not asking about see through OLEDs. I am asking about segment displays. They are normally alarm clocks with see through segment display. What is the technology behind them? Thanks
I have some of the very same 7-segment single digit displays and had some fun turning on the segments by touching them with my fingers. Got them quite a few years ago intending to build a clock with them but haven’t gotten around to it as yet. What I have been looking for is a 12-14 digit 7 segment static drive (non-mux) display. I don’t suppose anyone out would know where I could buy one?
Could you read the display too? That way one could refresh without memory. Have a window comparator check if the voltage is not around zero and then invert the voltage to full level.
In more Advanced applications there is not a common electrode, but rows and columns. You apply voltage pulses ( limited by chemical reactions) only for short duty.
Ah, so it IS possible to have an LCD screen that can use either reflected light or a backlight! I've been wondering for years if it was possible, and if so, why the phone manufacturers don't use it for their screens. Seems like it would be a good way to save battery power. Reflection when it's bright, backlight when it's dim.
I am looking forward to future videos. Interfacing the smaller two of 4 line displays with on-board driver chips is easy enough to understand but interfacing say a color display from a laptop, I'm lost. Displays for the Pie are available but you hook them up and run the software but that doesn't help understand how the interface works. Hope in the future you can cover the different interface requirements to these displays.
Great video! How would one go about to get a replacement lcd? I have an old electric surface plane meter with a broken display. I have had zero luck finding anything remotely like it when googling for replacement displays.
I'm concerned of the costs. If you are designing displays in a business, the design costs are not a large problem because you normally can spread the costs out over the production lifetime. But is it affordable for hobbyists to design their own displays? I doubt, but let's see what Dave comes up with.
I wonder what's the largest 14 or 16 segment LCD display out there? Is there any that's like 100 characters x 40 rows or something like that? I maybe exaggerating a bit there but would be interesting to see what the largest they go to is.
This is probably a lame question: Have you ever tried to use the electric field of a say a capacitor to light up LCDs not in a pattern but as an application like a flashlight. If all it takes to light up the LCD material is an electric field the field of a charged capacitor could act as a very long lasting LCD lighting device? Charge the capacitor and the LCD lights as long as the cap has an electric field, and a cap is nothing but an electric field.
Do you get the backlash I get every time I mention patreon? I mention that word, and loose about 500 subscribers immediately and get every crackpot tell me a story why they will never support anyone on patreon and how patreon funds hate groups ect.
I mentioned that in light to the demonitozing by youtube that I was going to start putting up some exclusive videos for patreon supporters in an attempt to grow my patreon base, as out of 26,000+ subscrivers, I have 40 or so patreon supporters. It blew up in my face and I lost close to 1000 subscribers over about a week. I do release some exclusive content for patreon supporters, and some long edits of public videos, but I still see very few people willing to support me. It is still 99.9% youtube revenue that keeps my channel going, which like yours is mostly an electronics repair / build channel that I have had going for about 6 years.
Yes that is one way to look at it :) Every content creator is more than happy to loose a few undesirables. You know the ones that thumb down every video no matter what, or criticize the way you do something, or the way you pronounce a word. If I could I would reach out ans slap a few people that try to convince me that the word SOLDER, is pronounced sodder and I get the same people trying to "educate" me.
