I'd bought this 2.7" Passive NFC-Powered e-Paper Module (pictured right) a couple years back with intentions of messing around with it to see it's potential uses. I'm a big fan of Waveshare, and love all their product line (and blogged about another product a while back). My initial plans were to incorporate it into my front door to identify doorbells for rental properties. It works as promised and holds the image forever on its eInk screen once you 'upload' it via NFC tapping (a bit of shimmy & shifting to get the ideal contact point). The app is simple, but Chinese in origin, so no telling what data gets passed.
My initial plans for the module have changed, and the NFC eInk Module has been in the back of my mind for a while. With the latest rise in postal rates this past July 10, 2022, I realized I found a perfect use for it: I've been maintaining a spreadsheet of the current Media Mail Postal Rates for my digital conversion business. We rely heavily on the USPS and its low shipping rates. Still, we end up printing a small section of our spreadsheet and taping it to my computer monitor as a cheatsheet - changing it with each postal rate change. While the diminutive resolution of the NFC eInk Module is only 264 x 176 pixels, I was sure I could make the same data fit, and toss my wasted paper prints in lieu of a digital cheatsheet.
This is our end resulting image (seen right), with assorted # of stamps needed to achieve Media Mail pound (lb.) rates, along with the overages.. This allows us to use our ever-changing stamp inventory to add postage to our pre-paid 'Vinyl Simple Shippers' we mail out to our audio conversion customers.
Being a designer type, I can't just let this ugly blue motherboard sit exposed, so I whipped up a quick paper template to hold the module. Simply print at 100% on any printer. You can follow the very simple instructions on the printed sheet. It's simple to cut on the printed side, and fold inward, so you keep a clean outer appearance. I used some double-sided tape to attach mine to the bottom corner of my monitor, and it now holds the module as a cheat sheet, as pictured below:
One last note, Waveshare usually carries all sorts of plastic carriers for many of their eInk screens, but this odd-sized one somehow never got made. My paper template is an attempt to make a low-cost (free) fix.
Special Thanks to ShrinkPDF, who compressed my downloadable PDF file by 94% and to my friends at TinyJPG, who easily shaved more than two thirds off our images, making this page load fast!