NFC smartphone power ratings

I am reaching out for advice since I am illiterate about NFC design. I bought a waveshare eInk 7" display which should update with the NFC on a smartphone. The company did forewarn that because of the large size of the display not all smartphones have enough power to update the display. Unfortunately it is almost impossible to know the power rating of any phone (and waveshare did not specify a minimum). I did purchase a repeater disk from this site which helped a little but not enough. I am curious how to figure out what NFC design or type will work. So far only a recent Samsung phone which I borrowed worked well. My Nothing1 is the weakest, but also Sony Xperia and Motorola were similarly weak.

Waveshare does recommend purchasing their own reader, but that would defeat the purpose of easily mounting tables or photos.

https://a.aliexpress.com/_mr6xYa3

When it does work it does work well!

I have an iPhone 14 Pro, and I cant seem to find any data on the NFC power output. But, I do find this interesting.

Here is basically what your describing but on a smaller display and in the form of a phone case.

(Kosprie E Ink Smart DIY 3-Color Electronic Screen Case for iPhone 15 Pro - 3.5inch Display, NFC Photo (Black) : Amazon.ca: Electronics)

What are you planning to do with it?

So Iphones and your Nothing phone would benefit from an RSP. Make sure however you use a field detector to find the optimal placement for the disc. Otherwise it wouldnt be helpful to just place it anywhere.

Regarding power ratings. I have designed a power meter with mobile devices specifically in mind to start documenting and listing out each phone’s current output so we can have a repository of sorts. However, with the current shenanigans with tariffs i have halted prototyping for it. I have all of the components except for the custom PCB which i havent ordered yet until all of this nonesense dies down. it may be soon, it may be soonish, but it is in the works.

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I hadnt seen that. Thank you. Since I wrote I tested an iPhone16 and it works extremely well. The Chinese distributor has been very helpful, but despite writing that it works on all phones they only actually tested it on Xiaomi and Apple phones. It was extremely cheap so it was an experiment. I was going to use it to display photographs and also to put up lists and various codes that I need when doing my job. The intention was to be able to change the data easily and quickly as needed.

I did buy a Dangerenous Things Repeater Disk (not a sticker). And through trial and error I more or less found the best spot on the phone (and you have to guess with tablet too since it isn’t marked) - but it doesn’t seem to do the trick. Would be great to hear about the power meter.

If you’re located in the US I’d be happy to send you a extender to see if that makes reading and writing to it easier and more convenient. Let me know through DM, I have a feeling it may be a better solution for your use case.

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Thank you for the offer. Unfortunately I am in Scotland but I could pay the postage. Do you mean that the 62mm repeater disc is not the right part?

No it’s totally the right part but you have two things to work with.

The location of your phones NFC coil, and the location of the tablets NFC.

I think if you had an extender it may make it a bit easier to get consistent reads with any device. Happen to have a link to the device you’re trying to interface with? I’d like to look into it a bit to offer you a better solution

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