Is E-ink Ready Yet?

Published on 2018-03-27 in CircuitPython Badge.

Of course the obvious solution for a display for a conference badge is e-paper or e-ink display. It has a number of advantages:

• keeps displaying with the device off, which means that you could even do without the battery, or — if you really want to have interactive elements there — have the microcontroller sleep most of the time,

• high contrast, readable from a distance,

• low resolution and color count — which means low RAM requirements,

• relatively new and very cool technology,

• physically robust (at least more so than glass displays) and safe when broken (no sharp edges),

It also has a couple of drawbacks:

• slow to update — even more so than the LCDs, partial updates help somewhat,

• expensive, at least until recently,

• requires additional components for the high-voltage driving — but any larger OLED has the same problem,

• no ready libraries — but I would write my own libraries for the display anyways,

• risky, requires research,

• no idea how easy to source it is in larger quantities.

But all in all, it is certainly an interesting option to explore. So I went to my favorite Chinese shopping website, and had a look around. Sure enough, most of those displays cost around 4x more than I would like the whole device to cost, but there are some interesting options. In particular, the GDEW0154T8 display can be bought for less than $5, even cheaper in larger quantities. But is there any documentation for it? Yes!

A bit of googling, and we can find this page , with links to the datasheet for the display and for the driving chip .

Looking at the datasheet, it doesn’t look bad. Resolution 152×152, 1-bit color, 6s refresh time — sure, not too great, but for that price what can you expect. More importantly, there is a typical application circuit example there, and it only has 11 capacitors, 3 Schottky diodes, a resistor, a mosfet and an inductor. There is also a temperature sensor, but looking at the breakout boards, it seems to be optional.

I could live with that. More details when the breakouts and displays arrive.\