[FeatureRquest] NFC

[bademux]

Hi,

I think it would be nice to have wireless communication with the world. As far as I understand NFC will be the only and the best choice here considering power usage and it's availability. I'm not sure why NFC is not considered in any of opensource watches.

Implementing NFC as sensor board was discussed here #31

In my opinion NFC can greatly enhance TOTP feature.

[joeycastillo]

I would love to see it, I just lack the expertise in terms of knowing whether an on-board NFC antenna would work within the constraints we have. I did a little test board in Eagle and cut it out on paper; I get the sense that there's about 9.4 mm x 8.7 mm available for the antenna. The top layer of the flex PCB can be available for this purpose, and it would sit maybe a few millimeters below the screen. If anyone has a sense for whether this would be workable, I'd love to get an opinion. The board file is OSO-MISC-22-004 WIP-NFC.

[bademux]

the same here, I'm not able to engineer good (any? :) ) NFC antenna.
waiting for someone who can help us and tell can we design passive antenna or are we able to use something like this on top of MCU.
Another idea will be to use custom circular antenna embedded into custom watch glass, but it is still my fantasy...

[ccoenen]

The Solo v2 (software/hardware) has NFC and if I recall correctly it was not easy getting this right. So I think their antenna size could be considered as a bar you'd need to clear. Sadly, the antenna is not part of the hardware repository :-(

[nrg-fv]

This is probably the answer to adding NFC support, at least antenna design is available. I'm not sure if any additional hardware would be required (probably yes) and if this all can be somehow connected to the board. I hope someone with better knowledge can explain.

https://n-o-d-e.net/datarunner.html

[bademux]

looks like NFC antenna behind the LCD will not work (https://youtu.be/aGn2_zP8GI8?t=66).

[814d3]

The showed and working solution seems to be practicable. The thin antenna can be placed "somewhere" but the wiring could be tricky - or am I wrong?

[ccoenen]

also a larger area would likely work even behind the display. The sticker shown in the video is tiny and antenna size does matter.

[bademux]

well, as far as I understand there is no place on the board for antenna (?).
And for compatibility LCD is the only place: watch body can be metallic.

[trash-anger]

Imagine being able to flash OTA from NFC! 😄 (no more usb!)