paperd.ink is a 4.2" e-paper display coupled with an ESP32 microcontroller. It's open-source,
fully hackable and all the PCB and 3D printing files are available on our Github repo. It’s low
power so you can run it for a month on a single charge. Update wirelessly using WiFi, Bluetooth. Display your calendar, to-do list, weather, custom images, whatever you want. Code using
micropython, Arduino, or ESP-IDF.
It was too hard to launch a hardware product on a shoestring budget dealing with way too many issues amidst the pandemic. But thanks to the HN community, we got a great response last year on our prototype which gave us confidence to move forward!
Looks awesome! For the <20uA deep sleep power consumption, is that out of the box when calling the ESP32's deep sleep? Or does it require any extra work like desoldering power LEDs and USB chipsets?
Oh no need to desolder, just disable some MOSFETs usings GPIOs in the code. The MOSFETs enable/disable parts of the circuit like SD card, e-paper, battery monitoring, etc
If I may, one suggestion regarding the plastic frame - maybe work a bit on the quality and feel of the frame (unless pictures are of a prototype). I know it may not sound like a big deal, but I think that a good product presentation goes a long way.
“You can download the STEP files from our Github repository to 3D print your own if you decide to go with the latter. Or even design your own!”
It would be really cool to mill the same design out of wood. An alternative design could be stackable layers of wood & plastic, similar to the RPi “zebra” cases.
I built a similar project (https://github.com/taylorconor/inkymon) using an Inky wHAT e-ink dev board [1] connected to a Raspberry Pi Zero, which seems to be the same display as used here.
It's really not fit for this calendar / todo list use-case. It's not possible to get much information density on a 400x300 two-tone display. No anti-aliasing or hinting on the fonts, for example. So you either need great eyesight or very few todos :)
I used the Inky Impression with some bash scripts, also connected to a Zero. It has 7 colours, which gives some neat expression. Here's a Twitter thread with pictures: https://twitter.com/berenguel/status/1344016064196304899
The rotating images keep me entertained during the workday.
The website is not stating one of the most important fact: what is the size of the display? Also on indiegogo you need to scroll and read a lot until you find what size. It is 4.2".
Sorry this is the best pricing we have right now. And no plans yet for the 6" version, depends on how we do on this one. E-paper is quite hard to source and is expensive.
Similar product: M5Stack Paper [0], has a 4.7 e-paper display and is based on the ESP-32. M5Stack also sells on AliExpress and ship surprisingly fast there.
It's not listed on aliexpress anymore, it's out of stock on their own site and on banggood where it was listed as in stock my order just sat as processing for 2 months and then they cancelled it with the reason "Some of the items in your order are out of stock". When they cancelled my order the product was still listed as "in stock" on their site.
From my experience M5Stack products pop in and out of stock in AliExpress frequently. I own a lot of them, and just check AliExpress until it’s available. Recently, their shipping time has improved there, my last purchase was made in May 26th, shipped in May 27th, and delivered to my house in Brazil on June 7th.
Since February, every time I go to their shop (both on their site or AliExpress)it's always out of stock. I don't know if they sell batches very quickly or have been out of stock for months.
I've seen another supplier selling them, but like 30 or 40% more expensive, for more than 100$.
Congrats on launching. Looks really promising and I'm excited what can be done with it. Any thoughts on final pricing? I understand the biggest cost are those overpriced e-ink panels, will the post-indiegogo price also be around 60 EUR?
Thanks! That's correct, e-paper displays and the silicon chip prices are high right now (the last we checked before our campaign launch in April) plus the inflation and uncertainty around shipping. The answer to your question is difficult to give right now, it depends on how many orders we get and what price we're able to negotiate. We put all our savings into the prototype and have been bootstrapped, thus the crowdfunding. Hopefully we'll be in a strong position with enough orders to get good prices after the campaign. Hope that helps!
This is a big deal because it’s a tablet with a GUI without Linux. This allows it to run on a microcontroller-class processor, with absolutely zero software bloat. Even if you wanted to slow it down with bash scripts and python, you couldn’t.
Looks very promising, but I am curious regarding the fixed goal of €25000: according to a quick napkin calculation, summing up all the units up for sale with their respective price, that still is only €20500, how does it work? Will you add more units to the page down the line?
The answer is in our FAQ. There were secret perks (accessible through the link) to our early backers which were sold, that's why even the number of backers won't match on the public page.
Not an export on this but I heard what blocked a lot of projects based on kindles was the proprietary waveform driver stuff to draw on the displays. Meaning that basic linux had supper inefficient redraw behavior compared to what the eBooks are doing.
Product is looking very promising.
Unfortunately using Indigogo. This is literally the worst crowd funding platform I know. Lots of scam going on and Indigogo doesn’t care a bit about the backers because they get their share. Therefore this place is dead to me.
Unfortunately none of the major crowdfunding platforms support our country to collect funds. It's sad that you have a product but would not be able to launch it because of these issues. We somehow managed to go on IGG so that's the best bet we have right now.
It looks like none of the buying options include the display, just the board or board and enclosure. Is the display on the back side? Just not pictured or listed?
If it has to be purchased separately, it’s not called out either and there’s no reference to which display to buy on the indigogo page.
Buy a reMarkable 1 tablet (~$230) and put a VNC client on it, or run an alternative OS like Parabola-rM (http://www.davisr.me/projects/parabola-rm/). They have high-quality (flexible backplane) panels that are now sold cheaply.
I’m utterly inexpert in this area, but that doesn’t sound right at all; I think it should be more like 2–3 months, and probably even more.
3–4 days on a 2000mAH battery means over 20mAH per hour. You say deep sleep uses <20μA, which would be under 0.1% of the total here, so we can call that rounding error and just focus on the time when it’s actively doing something. Assume it wakes up every hour, takes 12 seconds to connect, fetch and render, before returning to deep sleep. 20mAH in 12 seconds is 6 amps. I’m not familiar with the actual power consumption figures, but https://lastminuteengineers.com/esp32-sleep-modes-power-cons... suggests an ESP32 chip with everything on is using up to about 260mA, and I seem to recall hearing that e-ink displays used a few milliwatts, but it’s hard to find details. All up, my extremely rough estimates are coming to active consumption more like 300mA, not 6A—so more like three months than three days.
(I haven’t been careful with the voltages in these calculations, but my impression is that you’re looking at about 3.3–3.6V on the battery and ESP32 chip. I think the 300mA is probably fairly significantly on the high side, since most of the system won’t be in use for all of that nominal 12 seconds. But I caution you again that I’m not competent in this field; I’m just a layman that thinks the numbers didn’t add up.
While I’m talking: why do most of these things, especially the batteries, cite current figures rather than power figures? Is there a genuine reason, or is it some kind of historical mistake, or something else?)
You're right, we made a mistake. I checked with my partner. Thanks for pointing out, it would be at least 1-1.5 months for 2000mAh. Talk about short selling yourself!
E-papers have a slow refresh rate, it takes about 5 seconds to display a completely new image. And considering it takes about 15 seconds to connect and download an image (based on network speed), we get current spikes upto 300-400mA during WiFi transfer. We can expect conservatively a 1-1.5 months life from a 2000mAh battery.
The mAh unit enables us to compare batteries easier I believe. Standard LiPo are 3.7V so given a mAh rating its easier to know which will last longer. While for a Wh unit you would have to calculate it.
> why do most of these things, especially the batteries, cite current figures rather than power figures? Is there a genuine reason, or is it some kind of historical mistake, or something else?
I agree it's not so helpful in practice; I think though it's because they're a store of charge, N electrons = capacity in Coulombs, and 1C = 1As (by definition) or more familiarly 1/3600 Ah.
This is true load or no load, so from C (As) and V (= J/C) you know the charge stored and the rate of depletion.
Maybe the real error is not Ah instead of Wh, but V instead of J, since the former will drop off non-linearly (in practice) under load and while draining, or with temperature; whereas I think J & C independently 'when new' would give a better picture, or at least one that will more obviously change over the life of the battery?
Sounds very reasonable, thank you! I could make it refresh 1/12th of the time (twice a day) and that should get me well past once a year maintenance levels. seems pretty reasonable of a product after all.
If I put something like this in my bathroom, where it could be exposed to freckles of water droplets and humidity often, how concerned do I need to be of a malfunction that could be disastrous (such as starting a fire when I'm out of the home)?
personally, I've opted out to use an analog LCD single-button-eraseable pen screen to draw memos. Adding a digitizer whould be great, but that would be a totally different device class. And price.
I realize why they avoid showing comparisons to reference points for size. 4.2” is absolutely tiny and useless unless you're holding it right in front of you.
WaveShare sells up to 13'' color e-paper displays. Go big or go home. The rest can be supplied by an ESP32 or a RPI, there's no need to invent (expensive) hot water here.
- RPI, and GPOS like Linux is a poor fit for a minimal battery-powered display like this.
- This uses an ESP32
- Re size: Depends entirely on the use. 4.2" is fine for some purposes.
- The color displays have a much slower refresh rate than monochrome, and (IIRC) can't do partial refresh.
Unfortunately Indiegogo/Kickstarter type funding makes this a non-starter for me.
On a larger note, I wish products would explicitly state it’s in a crowdfunding stage instead of misleading people and them only finding out when they scroll to the very bottom of the page.
It was too hard to launch a hardware product on a shoestring budget dealing with way too many issues amidst the pandemic. But thanks to the HN community, we got a great response last year on our prototype which gave us confidence to move forward!