Kindly Morrow
NFC E-Ink Display Keychain
Tap your phone to the keychain and the image updates instantly. No battery, no charging port, no app to install. The NFC field from your phone supplies the power for the refresh, then e-ink holds the image indefinitely at zero draw.
The keychain harvests energy directly from your phone's NFC radio to write new bitmap images to the e-ink panel. Standard NFC write apps on iPhone 7+ and any NFC-enabled Android work out of the box. No proprietary software, no pairing, no firmware updates, ever.
Things to build with this
- Write your WiFi credentials as a QR code to the panel and clip it by the front door. Guests scan it without asking for the password. When the password changes, tap and update in ten seconds. The QR persists on the display forever without any power source.
- Use the 1-bit bitmap support to carry a rotating library of pixel art badges. Load a new design from your phone before each event, meetup, or market. The image displays even with no phone nearby, making it a passive wearable that still changes on demand.
- Encode a vCard or portfolio URL to the panel and hand it to someone at a conference. They tap the keychain with their phone to pull your contact info, or scan the displayed QR if NFC is off. No app required on their end, no printed card to lose.
Key Features
- Battery-free operation: NFC field powers the display refresh cycle, e-ink retains the image with zero ongoing draw
- Compatible with iPhone 7+ and NFC-enabled Android via any standard NFC write app (no proprietary lock-in)
- 1-bit black-and-white e-ink panel at roughly 250x122px native resolution, apps handle JPG/PNG conversion
- High-contrast display: readable in direct sunlight, unlike LCD or OLED
- Swappable in seconds: load new pixel art, QR codes, vCards, or custom graphics with a single tap
- Keychain form factor with clip for keys, bags, or lanyards
- Works through non-metallic cases (silicone, plastic, thin leather) up to a few millimeters thick
Frequently Asked Questions
How does the display update without any battery?
NFC transfers both data and power over the same electromagnetic field. When your phone's NFC radio is close, the keychain harvests enough energy from that field to run the refresh cycle. Once written, e-ink holds the image electrostatically with no ongoing power draw, the same principle that keeps ink on a printed page.
What image formats and resolutions does this accept?
The panel is 1-bit black-and-white. Native resolution is roughly 250x122 pixels depending on the specific unit. NFC write apps convert standard JPG or PNG files automatically. Use high-contrast images and avoid fine gradients or halftones for the cleanest result.
Will it work through my phone case?
Yes, for most cases. Silicone, plastic, and thin leather are fine. Metal cases and cases with MagSafe rings or built-in magnetic wallets can block or scatter the NFC field. If you get inconsistent writes, hold the keychain against the bare back of your phone near the NFC antenna, typically in the upper third of the device.
Why we stock this
Curated by Kindly Morrow. We test and vet every product before it hits the store. If we wouldn't use it in our own builds, we don't sell it.
Things to build with this
Fun projects to try once you get your hands on it.
Split-flap board connected to Claude
Hook up a display to the Claude API and have it show you a new message every morning. Motivational quotes, weather, or passive-aggressive reminders to drink water.
Spotify now-playing display
Shows album art and track name on your desk display. Updates only when the song changes. Zero battery drain between updates.
Real-time crypto/stock ticker
Pull prices from an API, show them on the display. Flip between assets. Try not to check it every 30 seconds.
Ambient room dashboard
Temperature, humidity, air quality, and time on a bedside e-ink screen. Updates every 5 minutes, uses almost no power. Looks like a museum label.
