If I ever develop a board with an e-ink display, I will definitely call it: “The Inkling“. Until then I’m more than happy to use this name when referring to M5Stack Core Ink. E-ink displays are awesome. After playing with reMarkable2 (review) and M5Paper (review), the bigger brother of the M5Stack Core Ink, I’m totally in love with that tech. Now, you can experience it too without spending a fortune!
M5Stack Core Ink
You are forgiven for thinking that M5Stack Core Ink is yet another ESP32 based board with an e-ink slapped on top. M5Stack knows how to take a simple concept and turn it into an attractive board that will remove a chunk of your hard-earned cash from your wallet. Don’t worry, you are unlikely to regret that purchase.
On the surface, it’s a 1.54″ e-ink display attached to the ESP32-PICO-D4 microcontroller. Underneath it, there are other modules packed into this lovely white enclosure:
| CPU | 240MHz dual-core, 600 DMIPS, 520KB SRAM |
| Flash | 4MB |
| Connectivity | Wi-Fi, dual mode Bluetooth |
| Ports: | TypeC*1, HY2.0-4P*1 , M-BUS Female Connector，Pin Array/ Hat Expansion |
| Screen | E-ink GDEW0154M09 200*200px 1.54″ |
| Refresh Time（s） | 0.82 Partial refresh 0.24 |
| Buttons | Programmable *1 ， Reset *1， Power *1 |
| Others | RTC, Buzzer, Battery 390mAh@3.7V, Green LED |
| Extra GPIO | G25, G26, G36, G23, G34, G18, G21, G22, G14, G13 |
All of that packed into a board that fits your palm. The LEGO-compatible holes in the enclosure, make M5Stack Core Ink an attractive choice for kids, while the magnet inside the unit keeps the board attached to metal surfaces, turning this unit into a power-efficient mini display for your next project.
M5Stack boards go often out of stock, so I’m going to list a couple of locations where you can source the M5Stack Core Ink for yourself:
- M5Stack Core Ink on M5Stack store
- M5Stack Core Ink on AliExpress
- M5Stack Core Ink on Banggood
Shh… the Inkling is sleeping
What’s so great about e-ink displays? Power consumption. E-ink displays don’t use power to display content on their screen. In theory, you can keep the data on the display for months. The power is consumed when the display needs a refresh. While the trade-off is the refresh rate, in practice, not all projects require the information to be refreshed more than once every couple of minutes.
Thanks to the power-efficient display and low power processing cores of ESP32, you can run M5Stack Core Ink on battery power for a long time while displaying important information on the screen. Experts can take it to the extreme by utilising RTC (real-time clock) and bring the power consumption to as low as 1.5 uA. That’s a lot of days in a standby mode with the display showing your info.
Typical applications would be:
- Temperature sensor with a display
- Connected clock
- Tweeter Feed Display
- Status Display for home automation project
- and more
As usual, the sky is the limit and as M5Stack Core Ink is a development board, you will be able to do with it whatever you want!
More than specs
If you are new to the M5Stack brand, the specification alone won’t make you fall in love with their products. Just like other offerings, programming the M5Stack Core Ink feels like magic.
What’s so magic about it? To program (in both MicroPhyton and Visual programming) the M5Stack Core Ink board you will need a web browser. UIFlow lets you program and upload your code to the device wirelessly. Since the M5Stack Core Ink is battery powered, you can do all this without using a single cable. It feels like magic. Of course, if UIFlow isn’t your thing, you can treat it like any other ESP32 board and open Arduino IDE or compatible development environment and do it all your way.
It’s fun to try things out this way, and you can set up simple servo controls in a couple of minutes. UIFlow is flexible enough to create complex scripts without being too complicated. Just check out this very simple example I put together in 5 min.
In case you just want to try things out, M5Stack Burner allows you to flash designed by others firmware, or return to the stock firmware should anything go bad. It’s handy and it lets you try things out without the need for programming. As the board is relatively new, right now there are only 2 images: FlowUI firmware and factory test. With time, we should see more images to try.
Modules
Once you master the display and built-in modules, M5Stack has a collection of compatible HATs, add-ons and expansions that will keep you busy for weeks to come. Check out their store to see what fun modules you can get and connect without soldering.
Thanks to the Grove connector, GPIO top header and 16-pin header at the back, M5Stack Core Ink offers enough O/I to keep the unit connected with other modules and DIY electronic circuits of your choice. It’s a small but powerful package.
Final thoughts
M5Stack Core Ink offers easy to follow introduction to e-ink displays without breaking your bank, at $35 (M5Stack, AliExpress, Banggood) the board is much more affordable than M5Paper, as long as you don’t need a bigger, touch-enabled screen. With excellent hardware and software support, I have no problems recommending these for you, as each M5Stack board I had in my hands was a joy to play with. I have a great project planned for the M5Stack Core Ink, so if you want to see what I’m going to make – watch this space. If you have any questions, let me know in this Reddit thread.
🆓📈 – See the transparency note for details.
