Waveshare’s E-Paper Displays Work Without a Battery
2 min readOne of the main advantages of E Ink displays is now being used to launch a range of e-paper devices that don’t require a battery.
As well as being readable in sunlight, E Ink displays only require power to change what’s on the screen. This has led to the creation of popular ereader devices such as the Kindle, which boast battery life rated in weeks and months. Now, as CNX Software reports, Waveshare Electronics has gone a step further and replaced the need for a battery in such devices by relying on NFC instead.
Waveshare’s 4.2-inch and 7.5-inch Passive NFC-Powered e-paper devices can receive both data and power over NFC, the same technology used to wirelessly recharge smartphones. So when it comes time to update the e-paper device with new content, an NFC-enabled smartphone and NFCTag app can be used to handle the transfer and power required to perform the change. The end result is very cheap e-paper devices that never need to be recharged.
The 7.5-inch model has a screen resolution of 800-by-480, 170-degree viewing angles, and two-level greyscale output. The 4.2-inch model reduces the resolution to 400-by-300 and shares the same feature set as the larger unit. Screen refresh times are four-to-five seconds, but that also includes the wireless data transfer from the phone. The lack of a battery is also reflected in the price, with the 4.2-inch model costing $39.99, and the 7.5-inch model is only $68.99.
The one problem users may face in deciding to purchase one of these e-paper devices is the power requirements for a data transfer to work. Your smartphone might not have a powerful enough NFC capability, but Waveshare has a solution in the form of a dedicated NFC board with micro SD card slot for $22.
