R.E.A.D Hardware Choices
The R.E.A.D digital label consists of 3 key parts- the E-Paper Screen (see our previous blog about these here), a NFC (near field communicaton) reader and a microprocessor to tie these all together. Yes, it’s going to get geeky! Of course, it’s a little more complex than that and feel free to get in touch if you want any more in depth knowledge- I’m always happy to get really nerdy!
E-Paper and Microprocessor- Inkplate 10 (ESP32)
Phase one of the DOORS project enabled us to research e-paper screens and how they connect to microprocessors. During this research we came upon Soldered Electronics Inkplate range. Originally a crowd funded project, the Inkplate range saves us a lot of time and work by combining an e-paper display with an ESP32 (a popular arduino based microprocessor). This means we don’t need to worry about getting all the complicated e-paper connections set up and can use their ready made SDK (software development kits). They leave lots of options to connect other devices to so that was a big win for us. Finally and perhaps best of all, the epaper screen itself is recycled from a kindle further minnimising the environmental impact of the project and reducing the amount of electronic waste.
NFC Tag Reader
NFC tags are everywhere these days, espcially following the COVID19 pandemic that saw us switch to as many contactless methods as possible. Contactless payments, travel tickets, access control and business cards are all now commonplace and use this technology. We were amazed by the number of different types of reader, types of card and the ways these needed to connect to the microprocessor. These are all quite low cost- usually around a couple of pounds each, so we were able to buy a few samples and see what worked best.
Despite our best efforts we were not able to get the SPI based readers to connect to the inkplate. This is probably down to the connections it reserves for the epaper screen. This left us looking at I2C connection readers (sometimes called IIC). Of these, we went for the very popular RC522 chip thanks to its small size and low cost. Most crucially however was the good range it had so that tags didn’t have to get really close to them to trigger the label. Ease of use is a central pillar to this project so this is an important design consideration.
Now we’ve got our hardware we need some software- our next blog will look at the software design and how we have been working to make this easy to use and scalable for other museums.