For a monochrome display where refresh rate isn’t particularly important, there’s almost no better option than an E Ink display. They’re available in plenty of sizes and at various price points, but there’s almost no option cheaper than repurposing something mass-produced and widely available like an E Ink (sometime also called eInk or ePaper) price tag. At least, once all of the reverse engineering is complete.
[Dmitry Grinberg] has been making his way through a ton of different E Ink modules, unlocking their secrets as he goes. In this case he set about reverse engineering the unknown microcontroller on the small, cheap display show here. Initial research showed an obscure chip from the ZBS24x family, packaged with a SSD1623L2 E Ink controller. From there, he was able to solder to the communications wires and start talking to the device over ISP.
This endeavor is an impressive deep dive into the world of microcontrollers, from probing various registers to unlocking features one by one. It’s running an 8051 core so [Dmitry] gives a bit of background to help us all follow along, though it’s still a pretty impressive slog to fully take control of the system.
If you happen to have one of these price tags on hand it’s an invaluable resource to have to reprogram it, but it’s a great read in general as well. On the other hand, if you’re more interested in reverse-engineering various displays, take a look at this art installation which spans 50 years of working display technologies.
Pretty funny that it’s using an 8051 core. You could probably have a hardware engineering drinking game – start pointing at various devices in your home, and if any part of it ends up having an 8051 or derivative, take a drink. You’ll end up with alcohol poisoning before you even get out of your living room.
That sounds about right.
As foone on Twitter often says when doing a teardown:
“IT’S AN 8051, PEOPLE!
PUNCH OUT ANOTHER HOLE ON YOUR REWARDS CARD!”
It’s amazing how technologically superior a solution starts to look when you can license it for free.
Cue the impending RISC-V takeover…
What an thorough write-up he does for all his stuff. Amazing!
Though I still wonder how he got this tag as he seems to live in the US.
REWE is a big retail group with most of its stores in Germany and the EU. But there seem to be some in Russia, too, so who knows…
I love Dmitry’s articles. He’s fantastic. Guy got linux running on an ATMega chip after writing an ARM emulator for it!!!
It was donated by a friend to me for a cause
This price tag is unfortunatelly incompatible with upcoming inflation
Just turn off the dot and then it can show the price of bread as 10¹²
i need palmos on riscv/esp or STM arm