The Best Way to Hack Electronic Shelf Labels

You’ve probably seen ESLs (Electronic Shelf Labels) appearing in brick-and-mortar stores lately. They aren’t great for consumers, as they enable dynamic pricing. But retailers sure do love them! Regardless of how controversial they are, ESLs are pretty neat technology. If you want to play around with them, TagTinker is the easiest way to do so.

If you haven’t seen one in the wild yet, an ESL is a replacement for the standard printed price label on a store shelf. It will have an e-ink screen, a battery, and a controller with some communication capability for setting the displayed content, including the price. Because e-ink screens only consume power when refreshing display, the battery lasts a very long time and ESLs are practical.

The communication protocol varies based on ESL model. Some are wireless and they let store managers update prices in batches. But some rely on old-fashioned infrared blinking for data transmission. Curious hackers have found that many of them lack security entirely and rely on ne’er-do-wells not knowing how to access them—the digital equivalent of putting a really weird handle on your front door that burglars don’t know how to turn.

TagTinker is an app that lets you easily change the display content of supported ESLs. I12BP8 developed the app for the Flipper Zero, but you can use it with just a compatible development board and an infrared LED, together costing just a few dollars. If you use a Flipper Zero and the ESL in question supports it, you can scan its NFC tag to identify the target without having to decipher the barcode.

I12BP8 even created a companion web app to prepare payloads. That lets you sort through the supported ESL profiles, upload and edit and image, and export a file ready to load onto your Flipper Zero for transmission.

Of course, you shouldn’t go around messing with ESLs in stores. But TagTinker is perfect if you purchase some ESLs and want to start working with them.