[evan_]

I wonder why they didn’t use NFC. They could get away with a much simpler chip, or even a fully analog solution if they didn’t need the complexity of Bluetooth.

Seems like you could just about accomplish the same thing with a pair of NFC tokens, a photodiode, and some transistors. Basic components. Connect one of the two NFC chips to the coil depending on how much light is reflected off the test strip. When you scanned it with your phone the activated NFC chip would respond with a URL containing a unique ID which could be interpreted by the manufacturer.

[sofixa]

One reason i can think is that NFC wasn't ubiquitous on non-premium phones a few years ago, unlike Bluetooth.

[tyingq]

It still isn't ubiquitous. For example, the Moto G line of cheap Androids are popular, and most have no NFC.

[bushbaba]

iPhones only relatively recently started supporting nfc for non payment use cases. https://blog.nordicsemi.com/getconnected/native-nfc-support-...

[grishka]

Not all phones have NFC, especially cheap Android ones like Xiaomi, but every single one has Bluetooth.

[evan_]

Interesting how half of the replies to this blame Apple and half blame Android

[logbiscuitswave]

Or if they are already using Nordic chips, slightly more expensive nRF52832 can also do NFC.

[tjoff]

Because of apple.