Would a 1.5" display work? You can buy these [1] from AliExpress for $15 a piece. And for $19 you can get this board from Sparkfun with a built in LiPo charger [2]. Or course you can go way cheaper on the board + charger, but this one is pretty easy to use if you don't have much experience with electronics.
Well, 15 + 19 is already $34 and that doesn't include a case or battery. Of course there are much cheaper ESP8266 boards you could use rather than the Sparkfun ESP32 Thing but then you have to go through the trouble of programming it, building an enclosure etc all of which is probably going to cost you a lot more than $50.
I agree, doing it yourself is fun, but if cost is your main concern, then DIY is absolutely not the way to go. For reference, I recently finished relatively simple ESP32 sensor project and while the components by themselves probably cost about £20, I ended up spending about £150 in parts and tools over the whole process. The extra cost was down to breaking parts and ordering replacements, needing basic components such as resistors and breadboards which many will already have in their toolbox and needing to make about 10 different orders + associated shipping costs as I went through each revision of the design.
I agree with you. I think kits are too expensive and going the homebrew route is generally more fun and educational. But to answer: ePaper is expensive, $15-20 for that module. The rest of the components are cheap. You're paying for some profit for the designer, amortised development time, assembly (by hand?) and the fact that it should work straight away (i.e. so you don't spend time). Tindie also take a cut, 10-15%? Shipping isn't free for the seller either.
At work I grit my teeth and suggest we buy the dev kits because it's worth paying $100 for an official board to check something works tomorrow, vs 3 weeks for a PCB and 2 days of tinkering. But at home, as a hobbyist, I mutter under my breath and fire up Eagle.
Honestly, $50 is not expensive for a DIY device. If you were to purchase the main components separately, you could expect to pay about $30:
2.9inch E-Ink display module: $18.99 [1]
Wemos D1 Mini 8266 module: $2.55 [2]
600mAh Lipo battery: $1.87 [3]
USB-to-serial converter: $1.08 [4]
3D printed case: $5 ?
On top of that, this is a totally custom designed and assembled PCB which would cost any indie hardware hacker a lot of time and significantly more than $50 to produce.
Of course, if you were to get this mass manufacturered, you could probably bring the cost down to about $25 but I love Tindie because it gives makers a platform to share their products and consumers a place to buy very custom products that they do not have the time or money to make themselves.
Thank you spuz, I totally agree. Full disclosure, I'm the guy who develops and sells these modules. I do this in my spare time. I didn't have any experience in manufacturing and shipping products like these before. A very good friend who lives in China helped me a lot with designing and manufacturing the ESPaper modules. Normally in China you'd have a minimal order quantity of thousands not hundreds. But with his help we can do small batches. Small batches are a driver for the price per piece of course. But there are a lot of other costs involved, pure hardware costs are just little over 50%. You get the ESPaper in a nice package with a pretty enclosure. As somebody mentioned earlier payment gateways want to have a share. And to pay my friend in China for his work and hardware I have to transfer the money using Paypal or banks and they open their hands again. There might even be currency conversions involved, depending on the path the money takes. In rare cases a package gets lost on the way to the buyer or it arrives broken and you have to replace it.
For shipping I use a fulfillment service in China. If you order on Tindie I import the order in my own shop system. From there the order is exported together with orders that came in directly on my shop to the fulfillment center by API. I have to choose the best of sometimes 20 different shipping services and the costs for shipping are different for every case, depending where you live and if value added tax is pre-charged (e.g. EU countries). Then a guy in a warehouse in Dongguan walks to a shelf and picks one of my boxes, labels it and sends it off to you. I had to learn the hard way that sending without tracking is cheaper but quite risky. So I also put insurance on the orders. The guy in the fulfillment center also needs to get paid.
And I spent a lot of time developing a graphics library (MiniGrafx) which gives you a lot more freedom than other libraries available for these displays. And now I'm working on a web server application which will make it super easy to configure the ESPaper remotely. Choose a application (e.g. weather, Calendar, Meeting Room, Sticky Note), configure it and when the device wakes up next time it will download the image information from the server. So all that costs a lot of time and most of the code is open source or will be at one point.
I totally understand if you want to build this by yourself, since I am having a lot of fun doing it. But not everyone has that level of patience or expertise and those who don't I'm offering a short cut.
order enough of them and i expect you could get one of the sellers to give you specs. they just use 433MHz; shouldn't be too hard to talk to them once you know what to send.
I was able to find them here for cheap: http://www.pervasivedisplays.com/products
I have no relation to them, there might be better distributors, and I have not ordered these. They are available via Digikey
SHA-2017 had a really cool badge: https://wiki.sha2017.org/w/Projects:Badge. 2.9" e-paper display, ESP32, 1000mAh LiPo battery and firmware with an online "app store" supporting apps written in micropython.
Sadly, there were only a handful available after the event (for about €30). I'm hoping someone continues with the design, because I can think of quite a few applications, but I'm worried about breaking it.
They look cool! Thanks for sharing.
Asking as a noob to programming electronics, do you have any guides on how I can display a few characters on one of these?
As in which controller to buy, how to interface the controller to the display, and how to set myself up to program such a controller... etc. I can try if there are enough resources, but honestly I'm easily intimidated if someone says "Just get a ESPXYX900 controller and hook it up to ABC IDE and flash this ROM and there you go."
I can program in Python and I have heard of MicroPython. If only I can figure out how to get to a point where I can get my python program to execute on one of these tiny wonders.
I’ll give you a more realistic answer: if you’ve never done microelectronics interfacing, you won’t have much luck until someone develops a driver (“software api”) for a particular eInk display for a platform you’d like to use.
I’ve never used MicroPython, but the C APIs I’ve seen for LCDs for micro controllers are usually pretty straightforward. Depending on the level of abstraction, they might offer a basic “put this B&W/R&G&B pixel at location x,y” or a higher-level “print text xyz” type of interface, both of which are easily exposed to python’s ffi and consuming it from there should be no problem.
But the trick is waiting for someone to get that driver made.
I’ve been meaning to play around with mine, if there’s sufficient interest I could see how realistic writing up some Arduino-compatible code to interface with it and some instructions would be.
Thanks for the straight response. I was afraid this might be the case.
I browsed around Waveshare.com and they seem to have posted "demo code" for the displays you linked before. I will try to muck around with them later, but it'd most likely be beyond my understanding of display drivers.
It'd be incredibly cool to have a cookbook for "Arduino + Tri-color E-Ink display for displaying text" - for beginners. If you think you could muster time & motivation to develop such instructions, I can help with (1) personal donation of $20, and (2) Sponsoring a domain and a basic web page describing the project for others to follow with donation options directed to you.
Agreed. And the other thing that gets me is battery life. If I have to charge something every few weeks, I'd rather just run power to it and be done with it. In which case, I might as well just use a cheap phone.
That is totally up to you. You can run these modules from a wall wart if you like. The beauty about a battery driven device is that installation is so much easier. You configure it, use some magnets to put it on your fridge and it just runs for weeks or months. The module serves a very specific use case: it's like a smart sticky note. Easy to place, easy access to the information.
Right. But if I have to plug something in, then I might as well just use a cheap phone. Color display, full browser, touchscreen, sensors, etc. For twice as much money as this kit, I get a lot more value.
You could hunt for an older ebook reader on eBay with similar hardware if you're willing to spend some time getting it to do what you want. The older Kobos were pretty simple to modify for example.
3" display is enough for my need.
Small LiPo battery works for my need.
I can spend a few hours learning to program this thing with Arduino IDE or whichever tool is needed with a little bit of Internet handholding.
But, >$50(incl shipping) kits don't give me the value I look for. Why are they so expensive?
I'd happily buy a pre-made setup of (controller+LiPo battery+e-paper display) easy to program device if the price is < $30.