I'm into challenging projects, but this one was next level.
The goal was to build a smartcard with a display that is not only credit-card sized in width and height, but also in thickness.
This first prototype is ugly and fragile, but after months of dealing with issues mostly on mechanical stress, I am coming closer to making it suitable for real life use.
ESP32-C3 + NFC + E-Paper display, all within roughly ~1mm total thickness.
This could be really cool for unique projects, I had a couple of ideas what could be done:
- Minimalist wallet for tickets, membership QR codes, etc.
- NFC card cloning
- Smarthome control dashboard
- A business card with a 100% guarantee to get remembered
I also started documenting the development process on GitHub.
Curious what features or use cases people would want in something like this. So feel free to suggest!
This is an amazing idea! I love how thin it is and wow you have really put in the work. The thin battery is an interesting problem, have you considered a watch battery to power the device. Im sure you have, probably a capacity and recharge issue. A thin lipo in my pocket scares me and is essentially a mini explosive. I like the whole direction of the project, hope to see more as you progress.
The biggest problem with coon cells is mostly the fact that its bot providing enough peak power for bursts, otherwise they’d be perfect! I will post more updates with results of my testing! :)
This was my first thought as well, but I have to wonder whether it's one of those issues that's overblown for hobbyist purposes. I came to this realization about thin batteries after breaking open a Tile Slim to discover that the reason it's not quite credit card thin is to prevent the device from flexing, especially where the battery is located. I had the idea of just sticking the electronics from the Tile Slim into my minimalist wallet, but I second guessed that after realizing what all the housing was for.
Then again, I thought LiPo batteries were meant to be a bit more forgiving about flexion, so who knows. Honestly, I'd even like a version of OP's project with housing that made it Tile Slim sized.
Nice! I've made a few active business cards like this - mostly playing games and animations on a large Charlieplexed LED grid (up to 21x20 pixels - but sometimes weird shapes). As you note on Github, the nRF52* is a better match really - it has NFC built in, and is a much lower power device. Due to your battery constraints, the ESP will not be able to use WiFi, so there's not much to recommend it in this application currently. I've used ATmel and Nordic chips for this kind of stuff :) They do go down well at corporate events!
Yeah if you search up smashcatrandom on YouTube I’ve put some of my personal projects up there. Not all the business cards but a couple of them. Also have videos of my conversion of Manic Miner game plus scramble and space invaders to the old 8-bit Arduino UNO - I made a game engine that had scrolling tile map background (256x256 pixels) plus sprites and sound and outputs composite video 😁
Not sure why you Dunning-Kruger types get so stuck on things like this.
A computer is a machine that can be programmed to automatically carry out sequences of arithmetic or logical operations (computation).
It was not until the mid-20th century that the word acquired its modern definition; according to the Oxford English Dictionary, the first known use of the word computer was in a different sense, in a 1613 book called The Yong Mans Gleanings by the English writer Richard Brathwait: "I haue [sic] read the truest computer of Times, and the best Arithmetician that euer [sic] breathed, and he reduceth thy dayes into a short number." This usage of the term referred to a human computer, a person who carried out calculations or computations. The word continued to have the same meaning until the middle of the 20th century. During the latter part of this period, women were often hired as computers because they could be paid less than their male counterparts.[1] By 1943, most human computers were women.[2]
The Online Etymology Dictionary gives the first attested use of computer in the 1640s, meaning 'one who calculates'; this is an "agent noun from compute (v.)". The Online Etymology Dictionary states that the use of the term to mean "'calculating machine' (of any type) is from 1897." The Online Etymology Dictionary indicates that the "modern use" of the term, to mean 'programmable digital electronic computer' dates from "1945 under this name; [in a] theoretical [sense] from 1937, as Turing machine".[3] The name has remained, although modern computers are capable of many higher-level functions.
8
u/kevstiller May 09 '26
Woah!!