Android NFC tag actions don't appear as useful as I initially thought

thecapsaicinkid

Senior member
Nov 30, 2012
382
0
71
I've just read that actions toggled by tapping a tag must be reverted with a tap of a second tag and not simply by moving away from the first (e.g enabling Bluetooth when near a tag in my car dock) Is this correct? I may as well tap a screen icon if this is the case, surely? Is this a limitation of the technology and can proximity based actions be achieved with the right software and not incur excessive battery drain?
 

dagamer34

Platinum Member
Aug 15, 2005
2,591
0
71
What you want isn't how NFC was designed to work and would basically end up using way too much power.
 

Red Storm

Lifer
Oct 2, 2005
14,233
234
106
What OP wants would be a privacy and security nightmare. The only thing that keeps NFC secure is requiring extremely close contact to initiate.
 

shortylickens

No Lifer
Jul 15, 2003
80,287
17,080
136
It's called "NEAR" field communication (NFC) for a reason.

Near is relative.

HF can hit the ionosphere and bounce all the way around planet earth.
Cell towers have a few miles.
Wifi is anywhere between 50 and several hundred feet depending on the standard.
Bluetooth is a few feet depending on how powerful your device is.
NFC is like a foot or less.

But again, its all relative.

I will say NFC was specifically NOT designed to replace cellular or wifi. And I really dont think they intended it to replace bluetooth.
 

vshah

Lifer
Sep 20, 2003
19,003
24
81
you could toggle them using the same tag, probably. tap once to enable settings, tap a second time to disable them. i'm sure there are nfc apps out there that can handle toggle states.
 

shortylickens

No Lifer
Jul 15, 2003
80,287
17,080
136
I should say thats EFFECTIVE range.
Cuz unless its physically blocked, RF travels forever.
 

gorcorps

aka Brandon
Jul 18, 2004
30,739
452
126
It does not always know the tag is there like you are wishing it does. All NFC can do is "see tag>run commands" which means you'd need multiple tags to switch between multiple profiles. Like mentioned it was meant for quick communication and point of sale devices. The whole switching profiles thing seems to be a side benefit that some developers took advantage of.
 

trmiv

Lifer
Oct 10, 1999
14,670
18
81
I looked into NFC tags for switching profiles, etc, but the whole act of having to actively swipe to do it, and then swipe again to reverse it, made it pretty much useless for me. Also I've noticed in testing with my device, it has to be like right on the damn tag to work. So I can't just swipe within a few inches, I need to make sure I get it right on the tag. I may as well just toggle bluetooth on myself at that point.
 
Feb 19, 2001
20,155
23
81
it is one of those nearly useless features out there.... there *are* some uses, but honestly not that many. NFC's practically ignored in the GS4 launch.
 

dlock13

Platinum Member
Oct 24, 2006
2,806
2
81
I've never used Tasker, but that seems like something that would make sense for it to do. I mean think about it. You can add the NFC profile to it, and when it's taken away, it'll revert it back to not using Bluetooth or whatever. I don't know if that's possible, but I'm just assuming it could be!
 

Zaap

Diamond Member
Jun 12, 2008
7,162
424
126
I've just read that actions toggled by tapping a tag must be reverted with a tap of a second tag and not simply by moving away from the first (e.g enabling Bluetooth when near a tag in my car dock) Is this correct?
Not really.
NFC tags can easily be written as toggles, IE: the first read runs one command- say turn on Bluetooth and mobile data, turn off wifi, set screen brightness, whatever... then the next tap will revert all those- or really whatever else you want it to.

Let's say you want settings toggled when you put the phone on the dock, then toggled back when taken off the dock. This works, but problems arrise when after a given time the phone- still in the dock- will trigger the toggle action when you don't want it to. One method to combat this is write in an ignore time limit, IE: the toggle won't react until after a certain time has passed.

I find what works for me is I simply have my car dock NFC tag on the back of the dock, not on the front of it in direct contact with the phone. The phone only shifts enough to read the tag if I move it, so it toggles my settings on when I dock it, and off when I remove it.
 

vshah

Lifer
Sep 20, 2003
19,003
24
81
I've never used Tasker, but that seems like something that would make sense for it to do. I mean think about it. You can add the NFC profile to it, and when it's taken away, it'll revert it back to not using Bluetooth or whatever. I don't know if that's possible, but I'm just assuming it could be!


the thing is the phone does not know when the tag has been taken away...that's not how NFC was designed to work, unfortunately.
 

lopri

Elite Member
Jul 27, 2002
13,308
685
126
I've tried NFC for the first time with my N4 and N7 and came off unimpressed. It's kind of slow. But I could definitely see a useful scenario among friends, esp. on the street.
 

dlock13

Platinum Member
Oct 24, 2006
2,806
2
81
the thing is the phone does not know when the tag has been taken away...that's not how NFC was designed to work, unfortunately.

Understandable! I wonder if there is some way to make Tasker aware... Such as after the phone is placed on the tag, it will trigger an event that. Tasker watches and when, let's say, you shake the phone three times, it undoes whatever you did or something of that sort.
 

vshah

Lifer
Sep 20, 2003
19,003
24
81
Understandable! I wonder if there is some way to make Tasker aware... Such as after the phone is placed on the tag, it will trigger an event that. Tasker watches and when, let's say, you shake the phone three times, it undoes whatever you did or something of that sort.

yes, that would definitely be possible. tasker could for example start monitoring the accelerometer after seeing the tag, and could execute some action the next time the phone is moved. This wouldn't work in the car however.

I generally just use tasker without the nfc stuff, and it works well. Rarely do I need such specific location that i need an NFC tag. "Wifi near" is usually plenty accurate to determine if i'm at home, work, or elsewhere.
 

obidamnkenobi

Golden Member
Sep 16, 2010
1,407
423
136
I use Llama for this. An awesome location/tasker app, and it's free.

When I car mode (triggered by putting it in the dock) turn on blu-tooth. When leaving car mode turn it off (unless connected). Works great. I also have adjust volume when headphones connected/disconnected, set to quite when I get to work, silent at night etc etc.

I got some NFC tags and played around with it but didn't find it terribly useful. I also paid at the grocery store with Wallet once, ditto on that.

edit: llama also used cell towers for location, so not as accurate as GPS, but uses waaaay less battery! The one app with GPS location I tried was a massive drain
 

Midwayman

Diamond Member
Jan 28, 2000
5,723
325
126
Could you set tasker to scan for the NFC tag every couple of minutes? I wouldn't detect state changes right away, but it would probably be fine. I'm using the bluetooth MAC in my car, and the wifi networks at home and work to detect state right now.
 

thecapsaicinkid

Senior member
Nov 30, 2012
382
0
71
Got my tags last night. Set up one on the bedside table to switch my Nexus 7 to silent and disable wifi. A second tap reverts this. It works ok I guess, seems a bit flaky and the screen has to be on and unlocked. All these guides claiming NFC is great at daily automation are bunk imo.