Hi Ralph. Great work as always! I’ve worked extensively with the 1.54” displays for the last 9 months developing a product prototype. I’ve got both MH-ET Live and Waveshare brand displays which both use the GoodDisplay displays. Both very nice with the WaveShare being a few mm smaller in physical size. Other than that, they’re both great. Neither have the extra sram memory. That’s why I use mine with ESP32s. Yes, the colour displays are a real disappointment when it comes to refresh times. In fact, the 1.54” black/white/yellow version doesn’t even have the same resolution for it’s size when compared with identically sized b/w and b/w/r displays. And for that reason, you can’t use the same library. What a pain. But the black/white displays are glorious. My app has bitmapped images changing on the screen maybe every 15 seconds and after 9+ months of heavy use, there’s no damage to the b/w displays that I can detect. I’m running mine off esp32 Dev boards like my air conditioner project I showed you back in the summer. No issues. I will say that the partial update mode on the b/w displays is critical to the usability of epaper. The colour ones don’t support partial update so that’s why the full screen updates are the only option. I will say that it seems for mine that rotate really only applies to text and maybe graphics primitives. The bitmap images can’t be rotated in my experience. So I just rotate my images 90 degrees clockwise before I render them as bitmap byte arrays. No problem. I’m a fan of the b/w displays. I won’t be buying any more coloured ones. We’re now starting to see some displays that handle 3 or 4 shades of gray/red. But I expect that’ll still have a refresh performance hit. Enjoy your epaper!
I appreciate your Real World experience of the B&W displays here, Gord. I'll be looking at that library you mention too. It's not the end of the road for this screen yet (despite what I say in next week's video).
The strange update restrictions are not intrinsic to ePaper technology, I suspect these devices have been heavily optimised for low power and display retention at the expense of other qualities, and I suspect they are really intended for labelling applications. After all, the original kindle display was ePaper and has a very fast update, and can be updated as much as you like. Perhaps one of these might make a nice pocket appointment reminder updated every 30 mins or so? Perhaps with a docking station to charge it and provide connection to update the appointment list. As usual Ralph a very interesting video - keep it up!
@@newburypi mostly nearfield.. waveshare does this and a bare 11.2 inch too i think it was. "Waveshare 7.5inch Passive NFC-Powered e-Paper Evaluation Kit with NFC Reader TF Card and ST25R3911B NFC Board Wireless Powering Data Transfer"
Yes, I'm guessing (no more) that these were intended for real commercial applications (shelf edge displays, Kindles, till displays of special offers) and now we're (makers) being offered them but with the constraints they come with and which are not constraints for the original implementation at all!
@@RalphBacon yeah, the original 'role to role' plastic logic epaper was supposed to give you any size display you wanted for pennies an inch, the profiteers seem to have restricted end users kit to tiny epaper sizes though, and the new covid profiteers want you to pay quadruple rates today, shame
The first two are good examples of where this might be used, but even Treebeard moves too quickly for this display! Of course, when not actively moving it would be OK, bar a few leaves and branches occasionally changing a few pixels...
I have a temp/humidity sensor which updates every 4hrs so this would work for me. Didn't know anything about these so this was super useful cos I put the ESP32 to sleep after sending data to Google Sheet so it could still show latest value. Very useful video for me! Thanks
Thanks Ralph, back when I was fooling around with that stuff I tried using an Epaper Display to no avail. I wanted to make a simple outdoor weather station that would gather data points every do often, but it would only transmit the data back to the indoor reviver station with the Epaper Display. I figured gather data points every minute or so, and then transmit data every half hour or if there is a sudden sustained change for 7 minutes or longer. Indoors you can track of your outdoor air pressure to see if it's rising or falling. The EpaperDisplay would be perfect to show the temp., humidity, rising or falling pressure, if it has been raining or not, and total rainfall today, e.t.c.
That would certainly be a perfect implementation of an ePaper screen, Steven. You could even update every 5 minutes if your transmitter can stand the current consumption. The receiver would need to have something active to detect the transmission packet but other than that everything powered off, so could be battery powered too.
@@RalphBacon they could both be battery operated sleeping most of the day. Nevertheless you could track your weather, not the weather on the other side of town.
Ralph sure like that the sound level is so consistent between the cuts thanks. I had my 5 year old grandson last night he had a restless night and we watched you twice Glad to see you back at it 😀
Oh wow! Twice you say, Mark? A sure glutton for punishment! But seriously, thanks for watching and hopefully gaining some insights into these ePaper displays.
Thanks Ralph. This is a technology update for me. I played with a B/W e-paper display a while back and found it to be an interesting device but not one for which I had an immediate need. A couple of interesting points: my devise had no warning about continually applying power or about frequently updating the disply, and (if memory serves) I had the ability to update a portion of the the screen. I clearly remember watching a display with unchanging text and a counter that updated on the second. The update time for the counter was only a fraction of the time required to update the entire screen. This was a strong point for me, so I hope they have not lost this feature.
You're referring to a partial refresh, Dale, and not all screens support that - but this one should, apparently. Which begs the question, why doesn't the software do this (in a demo, for example). I guess I'd have to investigate that aspect further, as what you're saying sounds a good selling point for the screen.
I have been using a 4.2 inch screan displaying a weather station by UA-cam presenter G6EJD - David . It updates every 30 mins with just a small flash but it is only black and white and then the ESP32 goes to sleep. It might be worth getting in contact with Dave as he has done a lot with this type of screan.
Have had a Kobo Glo ereader for several years now... love it or the epaper display - WITH BACKLIGHT!!! Naturally Amazon then copied the idea! ;) It can do partial refreshes a lot faster, and a full refresh in under 2 seconds. I played with a black/white epaper display with an ESP8266 (I avoided the tri-state ones because of the time issue), and was updating it every minute like a clock without any issues. I also have a eink temperature/humidy display that updates every 30 seconds or faster, but that is only partial refreshes, and then a full screen refresh every half hour or so. It is pretty neat tech, and is perfect for things you want to be able to update, but not fast... things like price tags (as you mentioned), calendars, temperature, id tags, etc.
All part of the learning curve... And if it 'just worked' the first time, where would be the challenge/fun in that? ;) BTW, the temp sensor I have is the version one of this (non-bluetooth)... Over a year old, and still chugging along well. banggood.app.link/eHx90Lh3Qab
One use I put these too a few months back was a weather centre running on esp32. It displayed data from opennweather website through their api. This gave hourly and 5 day forecast.. Added humidity, temp, pressure sensors as well. Worked great on batteries with these displays. A crappy lion cell gave 2 weeks and if you upped the capacity you could have had months. Update was every 20 mins I think.
Hey Ralph, got my first ePapier Display about 4 weeks ago. And went a totally different way than you did: we're using the display for displaying measurement data over a rf24l01 connection. The display is a 4.2/300x400 pixel waveshare display with some logic onboard (and no color), so I can interface an ESP8266 (WEMOS D1) to the display without a lot of hassle - and without tearing these flex-connectors :) The ESp seems to be a way better match, since I didn't struggle with SRAM. As a library, I went for the GxEPD2, and after the intial cursing and hair-pulling, this really starts to work great. There's much similarity to the u8g2 for OLed Displays, so it feels a bit like home. GxPD2 can use the Adafruit GFX Library, so you get graphic primitives the easy way. And - you can import your own fonts. Adafruit has a fontconverter for that - wich you have to compile yourself... I know: what? So I threw it all into a VM, installed all these tools I'll never used in my life and did a successful compile run... talking about wasted time... anyways: it works. Refresh times for BW aren't that bad - I measured about 700ms for a complete screen refresh - while your MCU does nothing else. That could be bad for anything time critical (i.e. Wifi), but that's what you get. We do partial refreshes every two seconds - up til now the display didn't fail. Not sure if the 180 seconds you mentioned are only for colour displays - we're going to try this out :) Partial refreshes work pretty good - even after hours of 2 sec updates, text won't degrade. So - maybe your countdown can be done some way?
Hmm. That warning was not specific to this display, it was ePaper displays in general. But _partial_ refreshes can happen more frequently, as you say; I just couldn't find an example of how to do this.
@@RalphBacon With the GxEPD2 Library, display() takes a parameter; doing display.display(true); - triggers a partial update. Not sure if the adafruit-lib you're using does the same :\ And - as Andrew said - could be the case, that colour displays won't do a partial. Fingers crossed!
I've been using a Waveshare 4.2 BWR display for a year now driven by a LOLIN32 using the GxEPD2 library and I do a refresh every 30 minutes, it displays the next 11 events in my Google calendar because my memory is rubbish.
Well that was disapointing. NOT your video, but thr EPaper display. It is truly challenging to percieve a UI that would benefit from such a static display. It could be used to indicate the time of the next step in a sequencer such as a central heating control. It could be used to indicate the detail of the last alarm. However, it would be useless for programming a central heating control and the alarm indication would only be useful until one tried to change settings etc in response to said alarm. Oh! I just thought of an application: it could be used to display the contents of a large text file, given that it takes a few minutes to read the page. Somebody should take that idea up. I really had high hopes for EPaper. The fact that it draws no power for displaying static text would be very useful but the reality kinda puts the khyber on an interactive UI. Thanks for the very valuable heads up and for taking one for the team.
You are not the only disappointed person here, Michael. Some have indicated here that _partial_ screen updating might be possible more frequently but I never found out how to do that.
adafruit's gfx library (lacks basic functions for many boards), MQTT library (doesn't have several standard things like retain bits etc), and others have a lot of issues and are poorly written. It's unfortunate because they charge a premium for their devices.
And I thought it might be "pay back" time for me, so I opted to buy their screen/module. Whilst OK in the overall picture, I'm slightly disappointed about the white text on red box not working, but also no obvious way of doing a partial (and more frequent) refresh, as others have indicated here. Drat!
@@RalphBacon Yea it's unfortunate. The other library you used seemed to do it well, it might not be too hard to get that going horizontally on the screen.. or maybe adafruit doesn't even know their red background doesn't work...
I always thought these displays would be good for a event days count down. Only update the display once a day (Midnight). Like 125 days til Holiday, or wife's birthday, anniversary
Got a bunch of e-paper pricetags and they are a perfect usecase for them see an example of hacking them here ua-cam.com/video/c62D3Z-c5IM/v-deo.html With a custom firmware on the internal chip the estimated battery life is at about 5 years with 3 updates a day
Oh is that all, Aaron, 5 years battery life!!! Yes, the unplugged one on my workbench still is showing the same image after 2 weeks now so that is a big plus, for sure.
Good day, again, Ralph. I don't know if I could have some use for such a display, but it sure is good to know it's something that exist. One thing pops to mind, though. Is it possible to have some shades of grey or it's only black and white .. and red ? The absence of mid roll ads is something I appreciated watching this video. Thank you, my Friend ! Have a great day and stay safe !
Some newer screens have up to 4 shades of grey but I suspect they will suffer from the refresh flashy-flashy delay that this one did (just guessing). And I'm glad you didn't miss the mid-roll ads for items you have no intention of every buying!
If you decide not to clear the page but rather ad a second line of text under the previous printed text line, can that be done without the 3 minute delay?
Not with that display AFAIK... the tricolours don't support partial screen updates... Meaning it's the full screen 8 second update, rather than the 0.3 second partial refresh (or 2 second full refresh) of a B&W only display. Who would have thought that extra colour would be such a pain! :-O
I often order things and then think why, like oleds I get confused see a nice picture and then the thing arrives tiny about the size of a postage stamp and I cry a little for not fully reading the blurb:-)
No, they can be updated quickly (some of them are like 0.5 seconds) some of the red ones are faster as well. eink is better for stuff that barely changes though, it can be unplugged and still hold it's display (which makes it very useful for those e-book readers)
@@azyfloof Yea IDK, I never knew there were ones that had such a long wait time, but I've also never even looked at tri-colored ones (and still haven't, and probably won't lmao) black/white good enough for me on these low powered displays.
B&W screen update faster (less flickering) but Adafruit insist that the 180 seconds applies to all ePaper screens - but many here in the comments indicate that might not always be the case, especially if we can partially update the screen (that wasn't updated before).
@@RalphBacon Stands to reason the monochrome one updates faster cause there's less going on. The black white and red ones use different funky voltages to hold the three different particles in different planes, so the timing is more complex. Still, three minutes *between* updates sounds excessive, I'd love to know Adafruit's reasoning. Think I'm gonna have to delve into that
Not uncommon for Adafruit code to have a lot of bugs in it. Or library code in general for that matter. Many of them aim for quantity instead of quality.
I don't want to dis[respect] Adafruit as I think they do a great job of spreading the Arduino (and other) Word, but I have had to modify a few of their libraries to get them to work (or add missing features). I guess they always have other fish to fry.
I'll be certainly looking at this, Gord. It also seems that choosing a display with RED was possibly a mistake as not only is it slower but also prevents partial refreshes. Experience never does come cheap.
@@RalphBacon Hi Ralph. If you decide to hook up your display to an ESP32 Dev Kit using the GXEPD2 library, the typical pins are: SDI - 23, SCLK - 18, CS - 5, DC - 22, RST - 21, BUSY - 4 Happy epapering!
I've not tried the 3 colour version, been using a b&w epaper display from waveshare for 3 years in my radio streamer project to display the radio station logo, the unit failed a couple of months back, I had a spare available that I swapped out, from checking the failed unit the epaper part is ok, it's the board that has failed, the board on the replacement is a slightly different design in that it has a chip that my original doesn't have. Reason I went of an epaper is that I use my radio streamer in the bedroom and didn't want a display that would be noticeable when wanting to get to sleep, with it's high contract I can easily see the logo from 4 metres away. For the first year I was doing partial refreshes, you can get 3 to 5 partial updates before the logo shows fade from previous refreshes and you'd need to do a full refresh to get it vivid again. I now just do full refreshes, the appear of partial refreshes isn't as important as I thought it would be. Next I'll be looking at what to show on the display when I'm not playing the radio, thoughts are ISS passes, local weather, tide and river levels. github.com/lakeuk/Runeaudio-extensions
@@RalphBacon This clip in real-time was my partial update tests, as each update happens you can see more of the previous refreshes. ua-cam.com/video/jiGQ_NCsV8c/v-deo.html This second clip is speeded up, it's still using partial refresh but to avoid previous BMP imprint that you see in the first clip I had a white frame update in-between. ua-cam.com/video/SsokkCtfI-w/v-deo.html Currently I'm using full refresh code so get the full black frame when it changes stations. I only tend to change stations a few times a day. I wasn't aware of the 3mins recommendation, looking at waveshares FAQs this recommendation only applies to non-partial versions of the epaper displays, their demo for the partial compatible epaper include a clock changing ever second for 5-10 seconds.
Thanks for that information; it seems that B&W partial refreshes are more useful than colour, full-screen ones every 3 minutes. I will continue my investigations on the ePaper, perhaps non-Adafruit versions!
Hey Ralph! Depending on the display, so long as you flash full black, full white on refreshing the content, you can update it semi-frequently. If you look at the Amazon Kindle or any similar e-reader that uses eInk, they have ways to get around the limitations of the refresh rate. You wouldn't be able to put a countdown clock on it, but you might be able to use it for a clock or something every minute (since you could just refresh those pixels), depends on the technology though. I got a 2.75" screen to test things out with, but it needs a bit of a better processor to be able to handle the buffering and management of refreshing the individual sections. Edit: I also think u8glib2 has support for epaper displays too, which is quite a nice display library. :)
I'm beginning to think, Jess, that using the Adafruit module (with their library) was not the best approach after all. A raw screen with a separate driver and an ESP32 (for example, ie more SRAM) and a different library that allowed partial refreshes would have been "better". I might actually look into this a bit deeper and see what I can find.
@@RalphBacon Yeah, the one I found came with a connector for the raspberry pi and then had pins out for SPI (if I recall correctly), it was the same size as the Pi Zero W (which is a very nice, but smaller, slower and cheaper RPI board). Heath hasn't been that great for a few months though so I haven't been working, doing any of my projects or really paying much attention on UA-cam. Couldn't concentrate at al! Seems the whole world has gone a bit silly. I even forgot to email you about those naked Arduino modules you asked if I wanted one, just to give you the address. :( Sorry about that. I'm sorry to hear that your house sale fell through, I know how much stress is involved in just moving from rented places, so i can only imagine it's even worse selling somewhere to buy another place. Oh and remember the On, Off Kill circuit (the one to replace that LTC chip) that you designed for the ATTiny85 and you challenged me to get it working on the ATTiny13? A friend and I are designing a circuit board for it, making it as small as possible but with the highest ratings. At last count, the board was only 2cm x 2cm but could switch up to 8A! I'd love to send you one when it's done if you don't mind? I'm thinking of going back to the '85 just because the code space is very tight on the 13. :) Stay safe, catch you soon.
The space on the ATTiny13 is incredibly tight, agreed. Whilst my Door Open fridge alarm was an interesting academic exercise you do have to wonder whether such microcontrollers even have a place in the hobbyist arena (ie when you just buy one or two) any more.
Interesting. I'd been thinking about getting one of these to use in place of an OLED on some of the test fixtures I build. I guess that wouldn't work out very well, so thanks for the video. I wonder how this is different from what they use in things like the Nook Glow? Because I can flick back and forth and have it refresh the screen once a second or so, and it doesn't seem to have any problem. Also, none of the weird flashing and flickering during updating.
It seems the B&W displays (perhaps with libraries other than Adafruit's) allow _partial_ display updates more frequently so you still might be able to use them.
I played with a three colour epaper display and only got it runnig with a lowlevel library. It uses two bitplanes, one for black and one for red. If I remember correctly on both bitplanes, white is represented by 1. So I guess the library you used did not produce correct bitplanes ?
I have the ttgo esp32 epaper display with the badge demo code. still showing the same information i wrote to the screen over 3 weeks ago and haven't given it any power since writing.
Let me see... 32K bits with 8 bits in each byte, carry the one, divide by 8, subtract the first number you thought of if it's Wednesday... OMG you're right. Doh! 8 x 4 = 32 and I chose the wrong operand! Double Doh!🤦♂️
hi Ralph can you do a video on SPIFFS , i wanted to run a full website using SPIFFS and call elements from the normal memory but just cant get my head around it . your style of education is at my level of understanding . so i ay have a chance of following it.
Hi Ralph interesting display, your talk about powering off the display after an amount of time. A thought came to me could you not combine your project on the MOSFET power circuit to power off the Display when not in use and only power up when the Arduino has something new to display and it’s over 3 minutes.
IMO using these for pricing, says "dishonest business practice is standard here." Like, "this was $5.99 for the last guy, (the one in the cheap tacky track suit), but for you... in those threads... looks like you'd pay $9.99 (as the prices roll on the next isle over).' - So basically scAmazon. I haven't used epaper before. I thought about putting one in an AVR transistor tester at one point, but never did. It would be nice to have the transistor pinout remain visible until the next test is done. I thought it would be cool to use one of the tiny displays for a battery indicator on a deep sleep battery powered project. For a larger type of display like yours, I think I would make a daily weather forecast display although something like that is better suited for an ESP8266 or 32. I don't think it will help, but Ben did a video on the refresh physics behind epaper on his Applied Science channel awhile back :-) ua-cam.com/video/MsbiO8EAsGw/v-deo.html Thanks for the upload. -Jake
@@RalphBacon I watched it again after grabbing the link. He does animations at around 3 Hertz, and a counter to. His code is posted on his github, is arduino based, and he goes into the details too. Just don't get too distracted by that $30k scope Tek loaned him :-) I know how it is though. When I'm "over a project," I'm emotionally done despite any ulterior motivations I think I should have.
Nice video Ralph! They are frustrating little beasts aren’t they? I have been playing with e-ink display for my GPS project, using an early 1.54” 200x200 pixel screen from Heltec, and found the GxEPD2 library from Jean-Marc Zingg very helpful. Provided you remain aware of the potential to harm the screen, his partial update routines are brilliant. My display shows a square labelled for the OS Map grid reference (calculated from the GPS lat/long) and moves a dot around the square in real time using partial updates, representing the user’s location. Full refresh when you move to a new square. I have a version that runs on the same 2.13” Adafruit RBW screen, but without the partial updates. I think the Adafruit extras might mean that you’re locked in to using their library. Do take a look at Zingg’s excellent work here github.com/ZinggJM/GxEPD2
@@GnuReligion My first prototype is described here electronicssimoninthelakes.wordpress.com/2020/03/20/gps-uk-os-grid-reference/ It’s moved on quite a bit from there, so I’ll update again when the current problems have been ironed out!
@@RalphBacon indeed it is! To be honest, I had completely forgotten about the three minute rule until I watched your video, and even now I am somewhat sceptical as I have been field testing this evolving project for many weeks. The mercury switch has been ditched in favour of a “screen update” interrupt button - which I press far more frequently than once every three minutes - and it seems to be coping without deterioration. Time will tell, I guess. Here’s the square version which updates the moving dot in real time using GxEPD2 partial updates. This was more to satisfy my curiosity than for serious consideration in the finished product but it works very well. Sorry, no video! electronicssimoninthelakes.files.wordpress.com/2020/10/img_4064.jpg
Yes, I'm still thinking of where I might use this. At $20 it wasn't cheap so I'd like to use it somewhere meaningful. I have a couple of ideas but I'll tarry a while before making a decision.
Price aside, I'm disappointed in the technical limitations of these displays. The aesthetics during refresh are horrible, and one refresh every 180 seconds - can you imagine how few Paperwhites Amazon would have sold were the experience similar? Yes, I'm sure there are use cases for this display, but they seem to be few and far between. After all, if an imaginative guy like you struggles to find a use...
I hear you, Leroy. The black & white displays are better in this respect as they (1) display more quickly and (2) can be 'partially' refreshed so that the whole screen is not refreshed with the flicker. I've still got a B&W version on my ToDo list as I feel they are currently the better option for general use.
Hi Ralph, here’s a link to Kevin Darrah’s work with ePaper displays and low power MCUs. www.kevindarrah.com/wiki/index.php?title=EPaperBoard . His video encouraged me to buy a 4.2” screen and experiment. I used mine for a while display the data from my weather station. Unfortunately the weather station stopped working but I’ve not been successful in troubleshooting it.
I shall watch that later. Of course, young Kevin is using a larger screen well beyond my modest price range but it will be exhibiting the same behaviour, I suspect.
Ouch! That's quite a severe judgement, John. I agree the colour ones are slow but they do consume zero current once the display is changed. The Black and White displays seem a lot quicker and can be updated more frequently too. So for a weather station that updates every 5 minutes these would all be ideal. Or, their original purpose, OTA shelf edge price labels that can be changed at a whim (eg time of day). Not quite rubbish, then.
Hi Ralph. Great work as always! I’ve worked extensively with the 1.54” displays for the last 9 months developing a product prototype.
I’ve got both MH-ET Live and Waveshare brand displays which both use the GoodDisplay displays. Both very nice with the WaveShare being a few mm smaller in physical size. Other than that, they’re both great. Neither have the extra sram memory. That’s why I use mine with ESP32s.
Yes, the colour displays are a real disappointment when it comes to refresh times. In fact, the 1.54” black/white/yellow version doesn’t even have the same resolution for it’s size when compared with identically sized b/w and b/w/r displays. And for that reason, you can’t use the same library. What a pain.
But the black/white displays are glorious. My app has bitmapped images changing on the screen maybe every 15 seconds and after 9+ months of heavy use, there’s no damage to the b/w displays that I can detect. I’m running mine off esp32 Dev boards like my air conditioner project I showed you back in the summer. No issues.
I will say that the partial update mode on the b/w displays is critical to the usability of epaper. The colour ones don’t support partial update so that’s why the full screen updates are the only option.
I will say that it seems for mine that rotate really only applies to text and maybe graphics primitives. The bitmap images can’t be rotated in my experience. So I just rotate my images 90 degrees clockwise before I render them as bitmap byte arrays. No problem.
I’m a fan of the b/w displays. I won’t be buying any more coloured ones. We’re now starting to see some displays that handle 3 or 4 shades of gray/red. But I expect that’ll still have a refresh performance hit.
Enjoy your epaper!
I appreciate your Real World experience of the B&W displays here, Gord. I'll be looking at that library you mention too. It's not the end of the road for this screen yet (despite what I say in next week's video).
The strange update restrictions are not intrinsic to ePaper technology, I suspect these devices have been heavily optimised for low power and display retention at the expense of other qualities, and I suspect they are really intended for labelling applications. After all, the original kindle display was ePaper and has a very fast update, and can be updated as much as you like.
Perhaps one of these might make a nice pocket appointment reminder updated every 30 mins or so? Perhaps with a docking station to charge it and provide connection to update the appointment list.
As usual Ralph a very interesting video - keep it up!
I've seen many grocery store shelves with e-paper price tags. An ideal use. Need to find out if they are near-field updated or wifi.
@@newburypi mostly nearfield..
waveshare does this and a bare 11.2 inch too i think it was.
"Waveshare 7.5inch Passive NFC-Powered e-Paper Evaluation Kit with NFC Reader TF Card and ST25R3911B NFC Board Wireless Powering Data Transfer"
Yes, I'm guessing (no more) that these were intended for real commercial applications (shelf edge displays, Kindles, till displays of special offers) and now we're (makers) being offered them but with the constraints they come with and which are not constraints for the original implementation at all!
@@RalphBacon yeah, the original 'role to role' plastic logic epaper was supposed to give you any size display you wanted for pennies an inch, the profiteers seem to have restricted end users kit to tiny epaper sizes though, and the new covid profiteers want you to pay quadruple rates today, shame
Calendar, TODO list, high speed gaming display for Treebeard the Ent.
The first two are good examples of where this might be used, but even Treebeard moves too quickly for this display! Of course, when not actively moving it would be OK, bar a few leaves and branches occasionally changing a few pixels...
I have a temp/humidity sensor which updates every 4hrs so this would work for me. Didn't know anything about these so this was super useful cos I put the ESP32 to sleep after sending data to Google Sheet so it could still show latest value. Very useful video for me! Thanks
Glad it helped! Sounds like an ideal addition to your project. If you're using an ESP32 you don't need the module with extra SRAM either.
Thanks Ralph, back when I was fooling around with that stuff I tried using an Epaper Display to no avail. I wanted to make a simple outdoor weather station that would gather data points every do often, but it would only transmit the data back to the indoor reviver station with the Epaper Display. I figured gather data points every minute or so, and then transmit data every half hour or if there is a sudden sustained change for 7 minutes or longer. Indoors you can track of your outdoor air pressure to see if it's rising or falling. The EpaperDisplay would be perfect to show the temp., humidity, rising or falling pressure, if it has been raining or not, and total rainfall today, e.t.c.
That would certainly be a perfect implementation of an ePaper screen, Steven. You could even update every 5 minutes if your transmitter can stand the current consumption. The receiver would need to have something active to detect the transmission packet but other than that everything powered off, so could be battery powered too.
@@RalphBacon they could both be battery operated sleeping most of the day. Nevertheless you could track your weather, not the weather on the other side of town.
Ralph sure like that the sound level is so consistent between the cuts thanks.
I had my 5 year old grandson last night he had a restless night and we watched you twice
Glad to see you back at it 😀
Oh wow! Twice you say, Mark? A sure glutton for punishment! But seriously, thanks for watching and hopefully gaining some insights into these ePaper displays.
Thanks Ralph. This is a technology update for me. I played with a B/W e-paper display a while back and found it to be an interesting device but not one for which I had an immediate need. A couple of interesting points: my devise had no warning about continually applying power or about frequently updating the disply, and (if memory serves) I had the ability to update a portion of the the screen. I clearly remember watching a display with unchanging text and a counter that updated on the second. The update time for the counter was only a fraction of the time required to update the entire screen. This was a strong point for me, so I hope they have not lost this feature.
You're referring to a partial refresh, Dale, and not all screens support that - but this one should, apparently. Which begs the question, why doesn't the software do this (in a demo, for example). I guess I'd have to investigate that aspect further, as what you're saying sounds a good selling point for the screen.
I have been using a 4.2 inch screan displaying a weather station by UA-cam presenter G6EJD - David . It updates every 30 mins with just a small flash but it is only black and white and then the ESP32 goes to sleep. It might be worth getting in contact with Dave as he has done a lot with this type of screan.
A weather display would be good for this type of screen, John, certainly. I'll look up David on UA-cam, thanks for the tip!
Have had a Kobo Glo ereader for several years now... love it or the epaper display - WITH BACKLIGHT!!! Naturally Amazon then copied the idea! ;) It can do partial refreshes a lot faster, and a full refresh in under 2 seconds. I played with a black/white epaper display with an ESP8266 (I avoided the tri-state ones because of the time issue), and was updating it every minute like a clock without any issues. I also have a eink temperature/humidy display that updates every 30 seconds or faster, but that is only partial refreshes, and then a full screen refresh every half hour or so. It is pretty neat tech, and is perfect for things you want to be able to update, but not fast... things like price tags (as you mentioned), calendars, temperature, id tags, etc.
Perhaps I should have gone for the black and white display that allows partial updates. Sigh.
All part of the learning curve... And if it 'just worked' the first time, where would be the challenge/fun in that? ;) BTW, the temp sensor I have is the version one of this (non-bluetooth)... Over a year old, and still chugging along well.
banggood.app.link/eHx90Lh3Qab
One use I put these too a few months back was a weather centre running on esp32. It displayed data from opennweather website through their api. This gave hourly and 5 day forecast.. Added humidity, temp, pressure sensors as well. Worked great on batteries with these displays. A crappy lion cell gave 2 weeks and if you upped the capacity you could have had months. Update was every 20 mins I think.
Interesting! And a perfect Real World example of where this screen could be put to use.
Great investigation into an often overlooked type of display. Thanks!!
I admit to feeling a little disappointed with the constraints of the screen but many comments here show that it can be very successfully used.
Hey Ralph,
got my first ePapier Display about 4 weeks ago. And went a totally different way than you did: we're using the display for displaying measurement data over a rf24l01 connection. The display is a 4.2/300x400 pixel waveshare display with some logic onboard (and no color), so I can interface an ESP8266 (WEMOS D1) to the display without a lot of hassle - and without tearing these flex-connectors :)
The ESp seems to be a way better match, since I didn't struggle with SRAM. As a library, I went for the GxEPD2, and after the intial cursing and hair-pulling, this really starts to work great. There's much similarity to the u8g2 for OLed Displays, so it feels a bit like home.
GxPD2 can use the Adafruit GFX Library, so you get graphic primitives the easy way. And - you can import your own fonts. Adafruit has a fontconverter for that - wich you have to compile yourself... I know: what? So I threw it all into a VM, installed all these tools I'll never used in my life and did a successful compile run... talking about wasted time... anyways: it works.
Refresh times for BW aren't that bad - I measured about 700ms for a complete screen refresh - while your MCU does nothing else. That could be bad for anything time critical (i.e. Wifi), but that's what you get.
We do partial refreshes every two seconds - up til now the display didn't fail. Not sure if the 180 seconds you mentioned are only for colour displays - we're going to try this out :) Partial refreshes work pretty good - even after hours of 2 sec updates, text won't degrade. So - maybe your countdown can be done some way?
Hmm. That warning was not specific to this display, it was ePaper displays in general. But _partial_ refreshes can happen more frequently, as you say; I just couldn't find an example of how to do this.
I think the color modules don't support partial.
@@RalphBacon With the GxEPD2 Library, display() takes a parameter; doing
display.display(true);
- triggers a partial update. Not sure if the adafruit-lib you're using does the same :\ And - as Andrew said - could be the case, that colour displays won't do a partial.
Fingers crossed!
I'll check it out!
I've been using a Waveshare 4.2 BWR display for a year now driven by a LOLIN32 using the GxEPD2 library and I do a refresh every 30 minutes, it displays the next 11 events in my Google calendar because my memory is rubbish.
Excellent Real World example, for erm... darn, I can't remember what I was going to say now.
Well that was disapointing. NOT your video, but thr EPaper display. It is truly challenging to percieve a UI that would benefit from such a static display. It could be used to indicate the time of the next step in a sequencer such as a central heating control. It could be used to indicate the detail of the last alarm. However, it would be useless for programming a central heating control and the alarm indication would only be useful until one tried to change settings etc in response to said alarm. Oh! I just thought of an application: it could be used to display the contents of a large text file, given that it takes a few minutes to read the page. Somebody should take that idea up. I really had high hopes for EPaper. The fact that it draws no power for displaying static text would be very useful but the reality kinda puts the khyber on an interactive UI. Thanks for the very valuable heads up and for taking one for the team.
You are not the only disappointed person here, Michael. Some have indicated here that _partial_ screen updating might be possible more frequently but I never found out how to do that.
adafruit's gfx library (lacks basic functions for many boards), MQTT library (doesn't have several standard things like retain bits etc), and others have a lot of issues and are poorly written. It's unfortunate because they charge a premium for their devices.
And I thought it might be "pay back" time for me, so I opted to buy their screen/module. Whilst OK in the overall picture, I'm slightly disappointed about the white text on red box not working, but also no obvious way of doing a partial (and more frequent) refresh, as others have indicated here. Drat!
@@RalphBacon Yea it's unfortunate. The other library you used seemed to do it well, it might not be too hard to get that going horizontally on the screen.. or maybe adafruit doesn't even know their red background doesn't work...
I would try drawing the red rectangle, then the white-text-with-red-background on top.
Yup, did that. Worked in the other library but not the Adafruit one. Weird.
I always thought these displays would be good for a event days count down. Only update the display once a day (Midnight). Like 125 days til Holiday, or wife's birthday, anniversary
Sounds like a good implementation. That would run for years on a single battery with the microcontroller in Deep Sleep for most of the time.
Got a bunch of e-paper pricetags and they are a perfect usecase for them see an example of hacking them here ua-cam.com/video/c62D3Z-c5IM/v-deo.html
With a custom firmware on the internal chip the estimated battery life is at about 5 years with 3 updates a day
Oh is that all, Aaron, 5 years battery life!!! Yes, the unplugged one on my workbench still is showing the same image after 2 weeks now so that is a big plus, for sure.
Good day, again, Ralph.
I don't know if I could have some use for such a display, but it sure is good to know it's something that exist.
One thing pops to mind, though. Is it possible to have some shades of grey or it's only black and white .. and red ?
The absence of mid roll ads is something I appreciated watching this video. Thank you, my Friend !
Have a great day and stay safe !
Some newer screens have up to 4 shades of grey but I suspect they will suffer from the refresh flashy-flashy delay that this one did (just guessing). And I'm glad you didn't miss the mid-roll ads for items you have no intention of every buying!
If you decide not to clear the page but rather ad a second line of text under the previous printed text line, can that be done without the 3 minute delay?
Only if we can figure out how to do a "partial refresh", which I was expecting to find in the Adafruit demo but failed to do so.
Not with that display AFAIK... the tricolours don't support partial screen updates... Meaning it's the full screen 8 second update, rather than the 0.3 second partial refresh (or 2 second full refresh) of a B&W only display. Who would have thought that extra colour would be such a pain! :-O
The reason for the flick when using red, is that the RED ball in the bottom of the silo, that holds the colour balls.
Interesting walkthrough👍😀
Good to know, Asger. I see that true (multi) colour is now available (for a silly price) for these sorts of larger screens.
I often order things and then think why, like oleds I get confused see a nice picture and then the thing arrives tiny about the size of a postage stamp and I cry a little for not fully reading the blurb:-)
The devil is _always_ in the detail. Yes. We've all done that.
The maximum 3 minute update rate is a real kick in the teeth :( Does the basic monochrome display exhibit the same restriction?
No, they can be updated quickly (some of them are like 0.5 seconds) some of the red ones are faster as well. eink is better for stuff that barely changes though, it can be unplugged and still hold it's display (which makes it very useful for those e-book readers)
@@gg-gn3re I wonder why these ones need three minutes, that's crazy 😮 I have a monochrome one to play with at some point
@@azyfloof Yea IDK, I never knew there were ones that had such a long wait time, but I've also never even looked at tri-colored ones (and still haven't, and probably won't lmao) black/white good enough for me on these low powered displays.
B&W screen update faster (less flickering) but Adafruit insist that the 180 seconds applies to all ePaper screens - but many here in the comments indicate that might not always be the case, especially if we can partially update the screen (that wasn't updated before).
@@RalphBacon Stands to reason the monochrome one updates faster cause there's less going on. The black white and red ones use different funky voltages to hold the three different particles in different planes, so the timing is more complex.
Still, three minutes *between* updates sounds excessive, I'd love to know Adafruit's reasoning. Think I'm gonna have to delve into that
Very informative video SIR
Thanks! Nice to hear from you, Muhammad.
Not uncommon for Adafruit code to have a lot of bugs in it. Or library code in general for that matter. Many of them aim for quantity instead of quality.
I don't want to dis[respect] Adafruit as I think they do a great job of spreading the Arduino (and other) Word, but I have had to modify a few of their libraries to get them to work (or add missing features). I guess they always have other fish to fry.
And I do recommend the GXEPD2 library from Marc Zinng (ZinngM) on github. Really well supported.
I'll be certainly looking at this, Gord. It also seems that choosing a display with RED was possibly a mistake as not only is it slower but also prevents partial refreshes. Experience never does come cheap.
@@RalphBacon Hi Ralph. If you decide to hook up your display to an ESP32 Dev Kit using the GXEPD2 library, the typical pins are: SDI - 23, SCLK - 18, CS - 5, DC - 22, RST - 21, BUSY - 4 Happy epapering!
I've not tried the 3 colour version, been using a b&w epaper display from waveshare for 3 years in my radio streamer project to display the radio station logo, the unit failed a couple of months back, I had a spare available that I swapped out, from checking the failed unit the epaper part is ok, it's the board that has failed, the board on the replacement is a slightly different design in that it has a chip that my original doesn't have. Reason I went of an epaper is that I use my radio streamer in the bedroom and didn't want a display that would be noticeable when wanting to get to sleep, with it's high contract I can easily see the logo from 4 metres away. For the first year I was doing partial refreshes, you can get 3 to 5 partial updates before the logo shows fade from previous refreshes and you'd need to do a full refresh to get it vivid again. I now just do full refreshes, the appear of partial refreshes isn't as important as I thought it would be.
Next I'll be looking at what to show on the display when I'm not playing the radio, thoughts are ISS passes, local weather, tide and river levels.
github.com/lakeuk/Runeaudio-extensions
That display on your GitHub looks nice! How often do you do the partial refreshes? Can you do them every few seconds without damaging the screen?
@@RalphBacon This clip in real-time was my partial update tests, as each update happens you can see more of the previous refreshes.
ua-cam.com/video/jiGQ_NCsV8c/v-deo.html
This second clip is speeded up, it's still using partial refresh but to avoid previous BMP imprint that you see in the first clip I had a white frame update in-between.
ua-cam.com/video/SsokkCtfI-w/v-deo.html
Currently I'm using full refresh code so get the full black frame when it changes stations. I only tend to change stations a few times a day. I wasn't aware of the 3mins recommendation, looking at waveshares FAQs this recommendation only applies to non-partial versions of the epaper displays, their demo for the partial compatible epaper include a clock changing ever second for 5-10 seconds.
Thanks for that information; it seems that B&W partial refreshes are more useful than colour, full-screen ones every 3 minutes. I will continue my investigations on the ePaper, perhaps non-Adafruit versions!
Hey Ralph! Depending on the display, so long as you flash full black, full white on refreshing the content, you can update it semi-frequently. If you look at the Amazon Kindle or any similar e-reader that uses eInk, they have ways to get around the limitations of the refresh rate. You wouldn't be able to put a countdown clock on it, but you might be able to use it for a clock or something every minute (since you could just refresh those pixels), depends on the technology though. I got a 2.75" screen to test things out with, but it needs a bit of a better processor to be able to handle the buffering and management of refreshing the individual sections.
Edit: I also think u8glib2 has support for epaper displays too, which is quite a nice display library. :)
I'm beginning to think, Jess, that using the Adafruit module (with their library) was not the best approach after all. A raw screen with a separate driver and an ESP32 (for example, ie more SRAM) and a different library that allowed partial refreshes would have been "better". I might actually look into this a bit deeper and see what I can find.
@@RalphBacon Yeah, the one I found came with a connector for the raspberry pi and then had pins out for SPI (if I recall correctly), it was the same size as the Pi Zero W (which is a very nice, but smaller, slower and cheaper RPI board).
Heath hasn't been that great for a few months though so I haven't been working, doing any of my projects or really paying much attention on UA-cam. Couldn't concentrate at al! Seems the whole world has gone a bit silly. I even forgot to email you about those naked Arduino modules you asked if I wanted one, just to give you the address. :( Sorry about that.
I'm sorry to hear that your house sale fell through, I know how much stress is involved in just moving from rented places, so i can only imagine it's even worse selling somewhere to buy another place.
Oh and remember the On, Off Kill circuit (the one to replace that LTC chip) that you designed for the ATTiny85 and you challenged me to get it working on the ATTiny13? A friend and I are designing a circuit board for it, making it as small as possible but with the highest ratings. At last count, the board was only 2cm x 2cm but could switch up to 8A! I'd love to send you one when it's done if you don't mind? I'm thinking of going back to the '85 just because the code space is very tight on the 13. :)
Stay safe, catch you soon.
The space on the ATTiny13 is incredibly tight, agreed. Whilst my Door Open fridge alarm was an interesting academic exercise you do have to wonder whether such microcontrollers even have a place in the hobbyist arena (ie when you just buy one or two) any more.
Interesting. I'd been thinking about getting one of these to use in place of an OLED on some of the test fixtures I build. I guess that wouldn't work out very well, so thanks for the video. I wonder how this is different from what they use in things like the Nook Glow? Because I can flick back and forth and have it refresh the screen once a second or so, and it doesn't seem to have any problem. Also, none of the weird flashing and flickering during updating.
It seems the B&W displays (perhaps with libraries other than Adafruit's) allow _partial_ display updates more frequently so you still might be able to use them.
I played with a three colour epaper display and only got it runnig with a lowlevel library. It uses two bitplanes, one for black and one for red. If I remember correctly on both bitplanes, white is represented by 1. So I guess the library you used did not produce correct bitplanes ?
I'm assuming that too, Fred, as there is no physical limitation regarding the white-on-red scenario.
Hi Ralph, nice looking displays but can't think of a use for myself at the moment and a bit pricey.
Me neither! Not with their limitations, but then experience doesn't come cheap, hey?
I have the ttgo esp32 epaper display with the badge demo code.
still showing the same information i wrote to the screen over 3 weeks ago and haven't given it any power since writing.
As a badge, these would work very well. Anything that is pretty much static. 3 weeks you say? Will probably stay that way for months!
32k bits is 4k bytes, btw. :)
Let me see... 32K bits with 8 bits in each byte, carry the one, divide by 8, subtract the first number you thought of if it's Wednesday... OMG you're right. Doh! 8 x 4 = 32 and I chose the wrong operand! Double Doh!🤦♂️
hi Ralph can you do a video on SPIFFS , i wanted to run a full website using SPIFFS and call elements from the normal memory but just cant get my head around it . your style of education is at my level of understanding . so i ay have a chance of following it.
Great suggestion! I might well so that, it's on the list!
In fact, sooner than you might expect... keep tuned.
Hi Ralph interesting display, your talk about powering off the display after an amount of time. A thought came to me could you not combine your project on the MOSFET power circuit to power off the Display when not in use and only power up when the Arduino has something new to display and it’s over 3 minutes.
You could do that, or you could just power down the display by using the ENABLE (unused pin, in my demo) to turn it off. Either should work.
IMO using these for pricing, says "dishonest business practice is standard here."
Like, "this was $5.99 for the last guy, (the one in the cheap tacky track suit), but for you... in those threads... looks like you'd pay $9.99 (as the prices roll on the next isle over).'
- So basically scAmazon.
I haven't used epaper before. I thought about putting one in an AVR transistor tester at one point, but never did. It would be nice to have the transistor pinout remain visible until the next test is done.
I thought it would be cool to use one of the tiny displays for a battery indicator on a deep sleep battery powered project.
For a larger type of display like yours, I think I would make a daily weather forecast display although something like that is better suited for an ESP8266 or 32.
I don't think it will help, but Ben did a video on the refresh physics behind epaper on his Applied Science channel awhile back :-)
ua-cam.com/video/MsbiO8EAsGw/v-deo.html
Thanks for the upload.
-Jake
I'll be interested to see that video later as I want to know why these cannot be refreshed more frequently! Thanks for the info, Jake.
@@RalphBacon
I watched it again after grabbing the link. He does animations at around 3 Hertz, and a counter to. His code is posted on his github, is arduino based, and he goes into the details too. Just don't get too distracted by that $30k scope Tek loaned him :-)
I know how it is though. When I'm "over a project," I'm emotionally done despite any ulterior motivations I think I should have.
Nice video Ralph! They are frustrating little beasts aren’t they?
I have been playing with e-ink display for my GPS project, using an early 1.54” 200x200 pixel screen from Heltec, and found the GxEPD2 library from Jean-Marc Zingg very helpful. Provided you remain aware of the potential to harm the screen, his partial update routines are brilliant.
My display shows a square labelled for the OS Map grid reference (calculated from the GPS lat/long) and moves a dot around the square in real time using partial updates, representing the user’s location. Full refresh when you move to a new square.
I have a version that runs on the same 2.13” Adafruit RBW screen, but without the partial updates. I think the Adafruit extras might mean that you’re locked in to using their library.
Do take a look at Zingg’s excellent work here github.com/ZinggJM/GxEPD2
All very interesting. A low-power, GPS-centered, long distance hiking map is just the application I would like to try with an ePaper display.
@@GnuReligion My first prototype is described here electronicssimoninthelakes.wordpress.com/2020/03/20/gps-uk-os-grid-reference/
It’s moved on quite a bit from there, so I’ll update again when the current problems have been ironed out!
Is that the same screen as in my demo, Simon? How often to you update it? More often that every 3 minutes, I'm guessing!
@@RalphBacon indeed it is! To be honest, I had completely forgotten about the three minute rule until I watched your video, and even now I am somewhat sceptical as I have been field testing this evolving project for many weeks. The mercury switch has been ditched in favour of a “screen update” interrupt button - which I press far more frequently than once every three minutes - and it seems to be coping without deterioration. Time will tell, I guess.
Here’s the square version which updates the moving dot in real time using GxEPD2 partial updates. This was more to satisfy my curiosity than for serious consideration in the finished product but it works very well. Sorry, no video!
electronicssimoninthelakes.files.wordpress.com/2020/10/img_4064.jpg
I think is really cool technology but the implementation reduces the use cases
Yes, I'm still thinking of where I might use this. At $20 it wasn't cheap so I'd like to use it somewhere meaningful. I have a couple of ideas but I'll tarry a while before making a decision.
Price aside, I'm disappointed in the technical limitations of these displays. The aesthetics during refresh are horrible, and one refresh every 180 seconds - can you imagine how few Paperwhites Amazon would have sold were the experience similar? Yes, I'm sure there are use cases for this display, but they seem to be few and far between. After all, if an imaginative guy like you struggles to find a use...
I hear you, Leroy. The black & white displays are better in this respect as they (1) display more quickly and (2) can be 'partially' refreshed so that the whole screen is not refreshed with the flicker.
I've still got a B&W version on my ToDo list as I feel they are currently the better option for general use.
Hehehe new haircut, DIY i suppose? :)
Yes 😁
@@RalphBacon looks good!
Hi Ralph, here’s a link to Kevin Darrah’s work with ePaper displays and low power MCUs. www.kevindarrah.com/wiki/index.php?title=EPaperBoard . His video encouraged me to buy a 4.2” screen and experiment. I used mine for a while display the data from my weather station. Unfortunately the weather station stopped working but I’ve not been successful in troubleshooting it.
I shall watch that later. Of course, young Kevin is using a larger screen well beyond my modest price range but it will be exhibiting the same behaviour, I suspect.
"Sorry, did you mean Office Fan?"....
Erm... where, John?
@@RalphBacon You told your Alexa to turn on the Office (Workshop) Lights mine replied!!! lol
I have contol of the world via my videos!
Lets face it, its expensive, its very very very slow, basically, it complete RUBBISH !
Ouch! That's quite a severe judgement, John. I agree the colour ones are slow but they do consume zero current once the display is changed. The Black and White displays seem a lot quicker and can be updated more frequently too. So for a weather station that updates every 5 minutes these would all be ideal. Or, their original purpose, OTA shelf edge price labels that can be changed at a whim (eg time of day). Not quite rubbish, then.