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!
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 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
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.
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.
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.
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.
Yes! I've been waiting for this series. I've been wanting to experiment with LCDs for a while, plus I got a Raspberry Pi Zero (and RPZW) coming in the mail. Can't wait!
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 th-cam.com/video/4EL4xBxc5IA/w-d-xo.html
Dave, I loved this, thank you. I had to wait for the right day to watch it and pay attention properly, but this looks like being a really good series, thank you.
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.
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.
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.
Super useful, always fabulous learning how to do stuff & LCD displays are things I have stayed away from as there are so many possibilities, but this series looks like it will really help me get to be able to confidently use these lovely things. Thank you!
Great intro! Two questions about defects: 1) Is a black, distinct irregular blob the LC fluid leaking? 2) What is/causes a round-ish fuzzy "burn" spot?
Thanks for the video. Ever since I pulled apart things as a kid I've always wondered how LCD's were actually driven. They've been a mystery up until now :).
very informative. loved it. This video is no less than a blessing for me as i am working on these displays these days. Cant wait for the next videos. Thanks.
Good intro to LCDs. I package these displays into our products at work but not being a circuit designer it's nice to pick up the basics here. I hope you are going to cover how to interface these with micro controllers and give some cover to font sets to use. 5*'s Dave!
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?
In some cases reflective LCDs can be backlit but only 5~20% of light may pass through the reflective layer. Just use other types of LCD, such as transflective LCD!
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
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.
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
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.
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.
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.
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
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.
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.
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
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.
I'm new to electronics so I love watching your videos to gain knowledge. The only thing I don't understand is, if dc voltage will kill lcd's after a while, than how do calculators use lcd's?
You're wellcome. If you are capable of reading a datasheet, you could try the Microchip PIC16F916 microcontroller. In section 9 there is a description of different LCD drive modes.
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
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
BTW, why aren't reflective colour LCDs used in low power applications and ebook readers (instead of e-ink, which is expensive, especially in colour)? Are they more expensive?
GRBTutorials they are in some cases, the pebble smart watches and several activity trackers are using LCD for great power efficiency. Lcd does require a small hold current though and true flipping ink displays just stay.
GRBTutorials LCD "e-paper". Unfortunately vague term of e-paper used widely in market, e-ink is a brand (although used generically like Kleenex) of bit flipper display and there are others but any display that looks paperish could be called e-paper (think it is a specific brand as well.)
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!
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.
How can this trick work in case of large number of segments where you run out of GPIOs to drive each segment individually?
@@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 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
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.
There is a video which shows flicker on a Gameboy DMG. Can you let a passive LCD flicker faster than the eye can see using software?
Another presentation (style and content), many will want to emulate. Dave Jones, the educator!
Cheers.
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.
I was looking for the second video, then I realized it was published yesterday! I'm finally caught up. I thought this day would never come.
very useful tutorial, thanks Dave, looking forward to the next part :)
Dave, a tutorial on the multiplexing biasing would be great.
Thanks Dave. Looking forward to next video in the series. Very interesting topic.
Same. I want an LCD for my multimeter!
@@GRBtutorials hi, if you need an lcd, welcome to contact us at: www.szmaclight.com
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.
That was an excellent video Dave!
Excellent video, just in-depth enough to explain the differences, looking forward to the rest of the series
I've always wanted to know how to get custom lcd displays made. Looking forward to the other videos!
I love his enthusiasm! It's so adorable and makes me want to learn more
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.
Very useful video, it helps a lot. So easy to understand even for non Aussie listeners.
Dave is full powered today hahaha
My mom had a 16 segment display on a Hifi and I always sat in front of it watching the text scroll. Amazed.
Yes! I've been waiting for this series. I've been wanting to experiment with LCDs for a while, plus I got a Raspberry Pi Zero (and RPZW) coming in the mail. Can't wait!
do a tour of an lcd factory. i really liked that interview with those Aussie calibration engineers.
+TheAstronomyDude I would if there was one in Australia?
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 th-cam.com/video/4EL4xBxc5IA/w-d-xo.html
You tease! You get me excited for designing a LCD and now I have to wait.
:(
Thanks Dave! Looking forward for the next parts of the series!
This just took a lot of mystique out of the world, but it is very cool to see that simplicity was always there.
Dave, I loved this, thank you. I had to wait for the right day to watch it and pay attention properly, but this looks like being a really good series, thank you.
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.
You can buy microprocessors that do all of that in a tiny package for about two bucks.
Ben Eaters worst video card shows how to read out a frame buffer and send serial data without blocking a CPU.
uSupply LCD at 22:10! :)
I noticed that too. Is this the LCD you're going to show how to design?
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.
Did you purchase the LCD displays with money you withdrew from the ATM machine after you entered your PIN number?
John Drachenberg I think he did, and he drove them with AC current while squeaking in the HF frequency spectrum.
Thanks much. It was great to learn about the different types. Looking forward to following the series and learning more.
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.
Great video, thanks Dave! We want more content from the junior Dave as well please.
That was a great tutorial on LCD display types. Spot on and makes understanding of these items so much easier
+Bruce Woods glad you liked it
Good things come to those who patiently wait. :) Thank you for an awesome video!
Super useful, always fabulous learning how to do stuff & LCD displays are things I have stayed away from as there are so many possibilities, but this series looks like it will really help me get to be able to confidently use these lovely things. Thank you!
Oh man this is great, can't wait for the part about designing a custom one, I've always wanted to do that!
Awesome tutorial Dave.... looking forward to the next episode.....
💚💚💚💚 bookmark/ notes: 11:14 strip / eraser pressure for the changing lcd …..ect……tbc….-g-b, bot
I love starburst displays too, and share your unabashed expression of glee.
Great intro! Two questions about defects: 1) Is a black, distinct irregular blob the LC fluid leaking? 2) What is/causes a round-ish fuzzy "burn" spot?
That that would be leakage. No fixing that.
Great video, very interesting. Looking forward to the rest in the series.
Love your instructional videos. Always learn something.
Great tutorial! Looking forward to the future videos in the series!
Thanks for the video. Ever since I pulled apart things as a kid I've always wondered how LCD's were actually driven. They've been a mystery up until now :).
very informative. loved it.
This video is no less than a blessing for me as i am working on these displays these days.
Cant wait for the next videos.
Thanks.
Good intro to LCDs. I package these displays into our products at work but not being a circuit designer it's nice to pick up the basics here. I hope you are going to cover how to interface these with micro controllers and give some cover to font sets to use. 5*'s Dave!
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?
How come that single-digit LCD has so many pins? It should only have 8 segments + common, but it seems to have 20. Is it just multiple connections?
In some cases reflective LCDs can be backlit but only 5~20% of light may pass through the reflective layer. Just use other types of LCD, such as transflective LCD!
That's probably a shit reflective display then!
EEVblog
Very common in Chinese displays! :)
love this kind of video, good topic, very informative, so worth the watch.
Super video, thanks, Dave! Some overview and then making an actual device is the best type of video for hobbyist like me :)
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
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.
The exact frequency is mostly important for the lifetime of the LCD. You should see something!
G'day mate, love it when I click on a random TH-cam video and it's another Aussie
Great video, looking forward to the rest of the series. I wonder why a channel like this would have it's videos demonetized though.
More tutorials like this please !
Off topic, I dig the chart behing you in the around 1:00 into the video. Please provide a bit of info on it.
Wonderful description!
good tutorial please keep going on with LCDs
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
Dave, it would be great if you can do a video on the operating hours and life of these LCDs.
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.
Good vid, Dave. Keep up the good work.
_Dave trims his right index fingernail at_ *13:50**.* ✂👆🏻
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.
so its not possible to make a transflective TFT?
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.
thank you very much for the explanation!
The LCD you removed from the zebra strips was a transmissive unit....
This is a great video, love to see this type of content dave!
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.
Amazing video Dave! Can't wait for the next ones :)
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
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.
An interesting topic Dave well done.
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.
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
Awesome! Will you do one on OLED displays too? Maybe do a teardown of one also?
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.
I'm new to electronics so I love watching your videos to gain knowledge. The only thing I don't understand is, if dc voltage will kill lcd's after a while, than how do calculators use lcd's?
The same way as any other app. having a LCD. The calculators control IC holds an AC driver circuit.
MrJetra thank you for responding!
You're wellcome. If you are capable of reading a datasheet, you could try the Microchip PIC16F916 microcontroller. In section 9 there is a description of different LCD drive modes.
Hi, Dave , great video, very informative, I will recommend it for reference.
Is it at all possible to get that long-sleeve shirt even thought their no longer available? I really want one.
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
Great video Dave!!! Very informative and interesting!!!
Nice video! Looking forward to see the next one 😊
today you are a rocket star.
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.
I guess there is an oxide layer everywhere, but on the original contacts.
Loved this video, thanks Dave!
Cool! I have a raw glass LCD. Have no idea where I got it, had no idea how I would use it, and still wouldn't use it since I have to drive it!
10:38 i have one of these screens but i took off the electro-pink thingys and i am wondering how to turn it on with just my hands. Any suggestions?
Excellent explanation!
Thank you for a cool educational video, Dave!
Awesome video, looking forward to more.
You actually have transmissive LCD in your lab - the 2x16 one you took apart (that blue one) is transmissive :)
What's your go-to prototype display driver/LCD for one off stuff?
Depends on the app. It if was a commercial one-off test jig or something for example then something like the 4D Systems modules are the way to go.
EEVblog hey Dave big hello from the uk
You can most probably use cheap FPGAs when it comes to parallel logic. I am expecting you to talk about it in the follow-up episode...
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
I really like where this is going! :)
fantastic video. I really appreciate this type of tutorial.
BTW, why aren't reflective colour LCDs used in low power applications and ebook readers (instead of e-ink, which is expensive, especially in colour)? Are they more expensive?
GRBTutorials they are in some cases, the pebble smart watches and several activity trackers are using LCD for great power efficiency. Lcd does require a small hold current though and true flipping ink displays just stay.
Didn't the Pebble use e-ink display?
GRBTutorials LCD "e-paper". Unfortunately vague term of e-paper used widely in market, e-ink is a brand (although used generically like Kleenex) of bit flipper display and there are others but any display that looks paperish could be called e-paper (think it is a specific brand as well.)
So that's how they made it colour. Still, it could be used in multimeters, for example (probably going to use one for mine).
Cheap LCD cannot do white and also fade out if you look just at a slight angle.
please do a series on camera devices or camera sensors also
awesome video btw waiting for next one
Can you still get custom VFDs?
19:00 isn't the glass of the 16x2 character lcd transmissive?
Very clear video tutorial!