Review: Four-Colour eInk Name Badge (HSN371) - plus Linux and Android tips
I wondered if there was a retail version I could hack around with. I found the HSN371. It is a colour eInk screen with a lanyard hole. The picture quality is amazing given the technology, the update speed is acceptable, and the supplied app is crap.
Colour eInk isn't designed to be as vibrant as an OLED display. But that's not why you get something like this. It uses no power to display the image, and will happily keep an image on screen indefinitely. The resolution is 240x416 which works out to about a PPI of 130. With only four colours (black, white, red, and yellow) you aren't going to get the Full HD Mona Lisa on there. But it is relatively easy to craft an image which looks good enough.
I used the Android app to flash a new image onto it. It takes a few seconds to transmit the image via BlueTooth. But, as you can see, it takes about 30 seconds of blinking before it is fully drawn.
There are cheaper versions available which are NFC only. They don't require a dedicated battery and are powered by the NFC radio of your phone.
