[Q] What size NFC sticker is necessary? - NFC Hacking

I realize there's a ton of different sites that sell NFC stickers and they all have various storage sizes ranging from 512 bytes to 2 Kb. So what's the general rule of thumb when it comes to actions vs storage space?
Obviously the higher the storage space, the more that can be automated with 1 tag. But say you just want to toggle a few system settings (volume, Bluetooth, brightness) and open one or two apps. Would a 512 byte tag suffice?
Maybe someone with more knowledge on the subject should create a guide generalizing this sort of stuff (broadly of course). I know it would certainly help me and any others wondering the same thing.

squiddy20 said:
I realize there's a ton of different sites that sell NFC stickers and they all have various storage sizes ranging from 512 bytes to 2 Kb. So what's the general rule of thumb when it comes to actions vs storage space?
Obviously the higher the storage space, the more that can be automated with 1 tag. But say you just want to toggle a few system settings (volume, Bluetooth, brightness) and open one or two apps. Would a 512 K tag suffice?
Maybe someone with more knowledge on the subject should create a guide generalizing this sort of stuff (broadly of course). I know it would certainly help me and any others wondering the same thing.
Click to expand...
Click to collapse
512k is a lot of space (where are 512k tags?).
Generally speaking 144 bytes (Ultralight C, NTAG203) is quite a bit and suitable for most applications.
If you need more space Classic 1K tags work (but these technically aren't NFC forum tags). 2K and 4K tags are generally overkill but are available.
If you are planning on using NFCTL most actions take 4-5 bytes (with the header being about 25 bytes). Actions that must store text (launching an App or URL for example) will store more space as they must store the string on the tag (generally 1 byte per string character plus 2 bytes instruction set).

Oh, oops. Meant to put 512 bytes. Correcting OP. Thanks for catching that.
Ok. So what about making a tag a toggle? Since (I imagine) you have to have a command for on and a command for off, does using it that way essentially double the space used?

squiddy20 said:
Oh, oops. Meant to put 512 bytes. Correcting OP. Thanks for catching that.
Ok. So what about making a tag a toggle? Since (I imagine) you have to have a command for on and a command for off, does using it that way essentially double the space used?
Click to expand...
Click to collapse
Unsure exactly what you're referencing. For a single Toggle command in a Task tag it takes no more space than enable,disable - the command merely indicates toggle instead of enable or disable. If you're referencing a switch tag then it writes essentially two Task tags to the physical tag (so that requires more space).

krohnjw said:
Unsure exactly what you're referencing. For a single Toggle command in a Task tag it takes no more space than enable,disable - the command merely indicates toggle instead of enable or disable. If you're referencing a switch tag then it writes essentially two Task tags to the physical tag (so that requires more space).
Click to expand...
Click to collapse
Haha my bad. I'm a total noob with this stuff (obviously) as I only got my Galaxy Nexus 2 weeks ago and only just started looking into this stuff. What I mean is 1 tag that when tapped once, turns volume up, screen brightness up, and opens an application, and a second tap will essentially revert the settings and maybe close the aforementioned app. Correct me if I'm wrong, but from the sound of my own description, it sounds like a combination of a toggle command (tap1: volume up, tap2: volume down) and a switch tag (opening and closing an app).
alicechong89 said:
512 bytes should be plenty.
On NFC Task Launcher, if I set these actions: enable wifi, set alarm, launch calculator, and set ringer volume, the total required is about 65 bytes.
Click to expand...
Click to collapse
Thanks for that bit of info, that clarifies things quite simply as I imagine that's pretty much all I'll be using the tech for.

curious why you wouldn't just make a profile using tasker to do the command combinations, then program the smallest tag to execute that one profile/script/macro ?
/first post!

danfinger said:
curious why you wouldn't just make a profile using tasker to do the command combinations, then program the tag to execute that one profile/script/macro ?
/first post!
Click to expand...
Click to collapse
Don't have Tasker and I'm not sure if I want to delve into its complexities, even though it would probably be easier (in some ways) to go that route.
Congrats on your first post, btw!

Related

[APP] 6/12 NFC Task Launcher 3.6.1

I am consolidating threads. Maintaining several threads was getting to be too much. Please move to the new thread here with any new questions or comments: http://forum.xda-developers.com/showthread.php?p=34417369
Market Link: https://market.android.com/details?id=com.jwsoft.nfcactionlauncher
Application Site: http://www.jwksoftware.com/
Screenshots: http://www.jwksoftware.com/screenshots
Where to get Tags?
http://www.jwksoftware.com/nfc-tags
Features:
NFC Task Launcher uses the NFC Hardware and RFID/NFC Tags to allow you to create tags several types of tags, including a custom "Task" tag that will automatically execute tasks when read. See Site for full feature list.
If you do use and enjoy the app it is up in the Market as a paid app. Any purchases / ratings are appreciated as I have put quite a few hours into this expanding it to fill requests for functionality.
Change log:
6/12 Version 3.6
- GPS (Root needed)
- Mobile Data (Root needed)
- Display Timeout
- Fixed Airplane mode bugs
- Precision timer
- New languages
- Cloud backup and restore
5/9 Version 3.4
- UI updates
- Added German, Spanish and Korean
- Removed Italian as it is out of date
- All tags now save to "Your Tags". Recent shows the 5 most recently used
- Changed Tag limiting to uniquely track switch tags
4/19 Version 3.3
3.3
- Added Google Places support in Latitude
- Added Navigate to address support
- Added Auto-rotation
- Added write lock option when writing
- Added size to vCards
- Added setting to pause after launching an app (for launching multiple apps or launching and then interacting)
- Added notification when tags save when hitting finish
- Updated Tasker integration (should fix issues with HTC One X)
- Enhanced debugging to make bug reports easier
- Fixed condition where tasks would stop executing when wifi changed
- Fixed reported crashes and typo
Full: http://www.jwksoftware.com/change-log
If you'd like to see some functionality added feel free to make a request.
The APK linked below is free of the license check of the Market version and is fully functional for 7 days.
http://goo.gl/xBBOU
For anyone who decides to purchase the app after using the APK attached to the thread - un-install the free version first otherwise the market installation may fail.
Here's a few videos I made for a current demo:
Tag Demos
Car Dock Demo
Awesome. I'm gonna have to research this. Off topic but how much do those tags cost?
My mind is racing with ideas.... oh no
player911 said:
Awesome. I'm gonna have to research this. Off topic but how much do those tags cost?
My mind is racing with ideas.... oh no
Click to expand...
Click to collapse
They are pretty reasonable. If you check out the site I compiled a list of shops that I've tested. Usually $1.15 - 1.50 a piece for Ultralight C or Classic 1K tags.
Question for you guys with the nfc tags what have you done with them I like the idea of swiping my phone over a credit card scanner but what can be created with your own tags
Sent from my SCH-I510 using xda premium
Can't wait to try this. Already ordered the starter pack from tagstand. Looks like an amazing app. Will definitely buy as soon as I get my phone = ]. Thanks for the hard work.
@krohnjw
Can these tags be pre-defined and written into the software?
Was just thinking, you could be onto a winner here.
Set your program to know whats tags are, so say put a tag for a store. When someone scans it with your app, it auto checks them in at whatever app they have installed
Evostance said:
@krohnjw
Can these tags be pre-defined and written into the software?
Was just thinking, you could be onto a winner here.
Set your program to know whats tags are, so say put a tag for a store. When someone scans it with your app, it auto checks them in at whatever app they have installed
Click to expand...
Click to collapse
The instruction set is encoded on the tag. Any user with the app that scans the tag will see the same actions performed. It makes no calls back to any server or outside service.
Sent from my Nexus S using xda premium
Ah ok, makes sense. How do you code the tag though?
Sent from my iPad 2 using Tapatalk
Evostance said:
Ah ok, makes sense. How do you code the tag though?
Sent from my iPad 2 using Tapatalk
Click to expand...
Click to collapse
It's fairly simple. I designed a basic syntax describing the actions to be taken and wrote a complementary parser for when the tags are read.
That's simply amazing. I knew the NFC would be a nice toy, but not that nice!
Does anyone know where to get some cheap tags in germany. Cheapest I found so far was ebay, but still around 2,50 EUR per tag (incl. shipping).
Atreus said:
That's simply amazing. I knew the NFC would be a nice toy, but not that nice!
Does anyone know where to get some cheap tags in germany. Cheapest I found so far was ebay, but still around 2,50 EUR per tag (incl. shipping).
Click to expand...
Click to collapse
Did you check http://www.tagage.net/tagage-shop/ ?
I purchased these nfc tags which the seller has confirmed that they are in working order and bought the application. However, the app says that the nfc type is not supported. What's up with that?
drdino said:
I purchased these nfc tags which the seller has confirmed that they are in working order and bought the application. However, the app says that the nfc type is not supported. What's up with that?
Click to expand...
Click to collapse
See the edited first post. Something in 4.0 changed and Mifare Ultralight, Ultralight C and Classic 1K tags are no longer reporting as NdefFormatable - so the functionality to format them TO NDEF is broken.
Essentially the NdefFormatable class verifies that the tag lists the tech before it will operate on them. As they no longer list that tech it refuses to do anything with them.
This affects all NFC Apps I've tried in the Market so far. If the tags are already formatted NDEF then they work without issue.
I've got a bug report open to see if I can get a response on this as well as a post on the dev group as it's not a listed change in the API changes anywhere from 3.0 up.
If you don't want to wait it out and want a refund let me know and I'll process it.
Its allright, seems like a decent app so I still want to explore the possibilities.
drdino said:
Its allright, seems like a decent app so I still want to explore the possibilities.
Click to expand...
Click to collapse
There are shops that sell the tags pre formatted with NDEF - those will work. Anything that comes blank though currently will not.
As a curiosity I sent an email to NXP as well to see if they have any more information. I'd like to get this sorted sooner rather than later so hang in there
Can this app be set to do something when moved away from an NFC tag?
So say you put it in car dock and a tag turns on BT. But when removed its turns off BT
Sent from my Galaxy Nexus using Tapatalk
Evostance said:
Can this app be set to do something when moved away from an NFC tag?
So say you put it in car dock and a tag turns on BT. But when removed its turns off BT
Sent from my Galaxy Nexus using Tapatalk
Click to expand...
Click to collapse
No, there's no intent raised when the tag is moved out of range, only when it is detected.
It is reported in the logcat, but to do that you'd need to constantly be reading the logs and scanning for that (which would involve a read logs permission).
For all Europeans: I contacted tagage and their tags are not pre-formatted by default, but if you send them an email, they'll format your tags first.
Atreus said:
For all Europeans: I contacted tagage and their tags are not pre-formatted by default, but if you send them an email, they'll format your tags first.
Click to expand...
Click to collapse
Most vendors don't pre-format their tags - so get in touch with them before/when your order for now to be sure.
Hopefully this is something that I can get an answer on, but I don't currently see a good workaround.
krohnjw said:
No, there's no intent raised when the tag is moved out of range, only when it is detected.
It is reported in the logcat, but to do that you'd need to constantly be reading the logs and scanning for that (which would involve a read logs permission).
Click to expand...
Click to collapse
Can you put implement it as an option on each tag? That way we could enable it for a car tag only and not another tag etc.
If that makes sense?
Sent from my Galaxy Nexus using Tapatalk

Tasker/Locale NFC Plugin

I just purchased this plugin to use with Tasker:
https://play.google.com/store/apps/....&purchaseButton=9yzEcX63VIYisA_oRMh13HqYUXs=
Seems to work ok, but ever time it scans my NFC tag it pops up a dialogue asking if I want to "Activate NFC condition" or "New tag collected". I just want it to kick off the action in Tasker without any dialogue. Anyone have experience with this plugin, or should I use something else?
Nevermind... got it working with NFC ReTAG FREE. Works great! Don't mess with the app I posted a link to above, it's a pain to use.
Glad you like NFC ReTag ;-)
For any questions: http://forum.xda-developers.com/showthread.php?t=1477138
kimboinatl said:
I just purchased this plugin to use with Tasker:
https://play.google.com/store/apps/....&purchaseButton=9yzEcX63VIYisA_oRMh13HqYUXs=
Seems to work ok, but ever time it scans my NFC tag it pops up a dialogue asking if I want to "Activate NFC condition" or "New tag collected". I just want it to kick off the action in Tasker without any dialogue. Anyone have experience with this plugin, or should I use something else?
Click to expand...
Click to collapse
Hi kimboinatl!
I'm the developer of the NFC plugin for Locale. The reason why this chooser pops-up is because there are multiple apps on your phone that can handle the NFC-tag that was scanned.
This can be solved by either disabling the other apps that the NFC scan action can choose from or you can create a unique tag following this guide.
I'm glad that you have been able to solve your needs with NFC ReTAG.
May I ask what it is that makes it a pain to use ? The feedback is greatly appreciated so that I might make it more pain free for other users.
Kind Regards
m3llon
m3llon said:
Hi kimboinatl!
I'm the developer of the NFC plugin for Locale. The reason why this chooser pops-up is because there are multiple apps on your phone that can handle the NFC-tag that was scanned.
This can be solved by either disabling the other apps that the NFC scan action can choose from or you can create a unique tag following this guide.
I'm glad that you have been able to solve your needs with NFC ReTAG.
May I ask what it is that makes it a pain to use ? The feedback is greatly appreciated so that I might make it more pain free for other users.
Kind Regards
m3llon
Click to expand...
Click to collapse
Hey m3llon,
I think the the problem was getting rid of the popup. Typically when there are multiple apps that can be launched from an action my phone gives me the option to select a default, but I couldn't do it in this case. I spent a while trying to figure out how to disable the popup, or if there was another app that was causing this, and had no luck, so I ended up uninstalling it. If there was a way to specify what the default action was I probably would have kept the plugin. Sorry if my feedback sounded a bit harsh, I was just grumpy after not being able to get it to work the way I wanted it to. Thanks for checking in with me about it, I appreciate the work you have put into it.
kimboinatl said:
Hey m3llon,
I think the the problem was getting rid of the popup. Typically when there are multiple apps that can be launched from an action my phone gives me the option to select a default, but I couldn't do it in this case. I spent a while trying to figure out how to disable the popup, or if there was another app that was causing this, and had no luck, so I ended up uninstalling it. If there was a way to specify what the default action was I probably would have kept the plugin. Sorry if my feedback sounded a bit harsh, I was just grumpy after not being able to get it to work the way I wanted it to. Thanks for checking in with me about it, I appreciate the work you have put into it.
Click to expand...
Click to collapse
Ok thanks for explaining what the neusens was. That have been fixed in the last update together with the workarounds that's linked in the app description.
Good luck with your future NFC endeavours
Sent from my Galaxy Nexus using Tapatalk 2
Just in case anyone else has issues with the popup, I find that using non-formatted tags doesn't produce a popup. Once the tag is formatted, or if you buy them preformatted, it doesn't look like it can be UNformatted though (wiped, yes.. but not unformatted)
When I first got my GS3 and started scanning everything possible, I found that some tags would produce the popup discussed (despite having no other nfc apps installed), and others wouldn't.. I ended up realising that unformatted tags don't produce the popup.
I ended up using the Tasker/Locale NFC Plugin as I didn't want something else running all the time when I had Tasker for that - and since the plugin uses the serial number (or what I assume is a serial number - it's different on each tag) rather than what's written on the tag itself, there's no need to format it - Same would apply with NFC ReTAG.
So as long as any tags are unformatted, you should be good to go.
So I bought the plugin and wrote the bad://access/developer URL to one of my tags. I scan it and Locale reacts accordingly.
But then what? Locale is in that situation forever.
Sent from my SAMSUNG-SGH-I727 using xda app-developers app
Trinition said:
So I bought the plugin and wrote the bad://access/developer URL to one of my tags. I scan it and Locale reacts accordingly.
But then what? Locale is in that situation forever.
Sent from my SAMSUNG-SGH-I727 using xda app-developers app
Click to expand...
Click to collapse
Yes, you will have to scan another tag to exit the situation.
For using Tasker with NFC Tags I like Tasker URL Launcher the best. Once installed you simply write a short URL that ends with the name of your Tasker Task to a tag then anytime you tap that tag it intiates that Tasker Task.
I did at one time have issues with those pop-ups (new tag collected) and through much searching found that I needed to disable a system app on my Galaxy S3 called "Tags". It wasn't there on ICS, but was after the update to Jelly Bean so not sure if it's something Android added into JB and not sure why they would or what it's purpose is, but disabling it fixed the annoying pop-up issue and has had no affect on reading/writing tags with various apps.
Kaibosh said:
Just in case anyone else has issues with the popup, I find that using non-formatted tags doesn't produce a popup. Once the tag is formatted, or if you buy them preformatted, it doesn't look like it can be UNformatted though (wiped, yes.. but not unformatted)
So as long as any tags are unformatted, you should be good to go.
Click to expand...
Click to collapse
They can be unformatted. Using NFC TagWriter by NXP (which I LOVE), you choose Tools > Clean. This resets the tag to factory default (unformatted). NXP manufactures the Xperia tags, they make nice products.
dragon_76 said:
They can be unformatted. Using NFC TagWriter by NXP (which I LOVE), you choose Tools > Clean. This resets the tag to factory default (unformatted). NXP manufactures the Xperia tags, they make nice products.
Click to expand...
Click to collapse
Thanks for that.. That definitely wasn't the case when I wrote the post as I'd tried with numerous apps (including NFC Tagwriter, which is also my go to app for writing) and using the Clear option left the tag wiped, but did not leave it in the same state as prior to formatting.
Also, the developer of the app implemented a direct url that could be written to the tags so that only this app is launched - so the need for unformatted tags (when using this app at least) is somewhat moot.
I have this app and I must say it makes building tasks extremely tedious.
If you want to scan the same tag twice, you have to put an action in your task to disable the first task after the first one is done and then put a disable of the task you are running in the second task.
Also, both need to run as exit tasks.
It would have helped if the dev used some better logic and came up with exit tasks on repetitive scan
Sent from my DROID RAZR MAXX HD
dragon_76 said:
They can be unformatted. Using NFC TagWriter by NXP (which I LOVE), you choose Tools > Clean. This resets the tag to factory default (unformatted). NXP manufactures the Xperia tags, they make nice products.
Click to expand...
Click to collapse
You can also use the app StartNFC Expert to "unformat" a tag. It's a great simple app for formatting/unformatting and testing tags and seeing what types they are etc.
It's extremely disappointing they the developer has completely abandoned this plugin.
Solution
Hello !
A solution I found to avoid this popup :
- Scan a tag (popup appears)
- Long press on the unwanted app
- Choose disable
- Enjoy the plugin
You can also go to your apps list and search "tags" and disable it
Hopefully pent does something with NFC in the next version of Tasker so we can be rid of this unsupported plugin.
Sent from my Nexus 7 using Tapatalk
Hoping someone is still using this plugin and can answer my question...
Do I have to have two tags if I want an on / off tasks? For example, I have hue lights and I would like to turn off the bedroom light on / off with the same NFC tag but not sure if that is possible
No.. Just use the check box for repetitive scan
Ignore: Haha I accidentally posted in the wrong thread.

Just a Few Questions

I was really wondering how much memory does a few lines of command take up? I just ordered some 144 kb tags because I can't use mifare classic cause I have a nexus 4. I was just wondering if that would be enough for a few toggles.
cfmusicman said:
I was really wondering how much memory does a few lines of command take up? I just ordered some 144 kb tags because I can't use mifare classic cause I have a nexus 4. I was just wondering if that would be enough for a few toggles.
Click to expand...
Click to collapse
144Kb tags!?? Are you going to store a whole library in it?
Assuming you ordered some 144 Bytes tags, the memory you need is just a few bytes more than the commands you are actually writing on it.
Also, some bytes are used internally, based on the tag technology.
Example (using MiFare UltraLight, which has only 64 bytes):
NDEF Command: Open site "http://www.google.com/"
--> 16 Bytes were used for MiFare UltraLight (UID, Access Conditions, etc.)
--> 8 Bytes were used for NDEF structure
--> 22 Bytes were used for your data (the link itself).
TOTAL: 46 Bytes used.
I'm using some apps on my Galaxy Nexus phone, that are really useful:
- NFC TagInfo --> Useful to show the raw data and some more technical information;
- Tagstand Writer --> Easiest app I found to write NDEF tags;
Hope I could help you.
cfmusicman said:
I was really wondering how much memory does a few lines of command take up? I just ordered some 144 kb tags because I can't use mifare classic cause I have a nexus 4. I was just wondering if that would be enough for a few toggles.
Click to expand...
Click to collapse
I think you mean 144byte tags right?
As for how much memory a few commands take up, I've attached a couple of images that should help you. These toggles were programmed onto 144byte NTAG203 tags.

Can't post long word. Forum will add spacebar.

Example the rom name K50a40_S112_150610_ROW_TO_K50a40_S114_150618_ROW_W CDE.zip
Forum setup long word to 50 characters.
123456789012345678901234567890123456789012345678901234567890
123456789012345678901234567890123456789012345678901234567890
Yep, this has always been the case, for as long as I can remember. Not sure if the limitation is vBulletin, SQL or something else?
We've encountered the same in our forum & turned out to be vBulletin bug.
@natong
It would be better if you put all those long filenames inside CODE tag.
Titokhan said:
We've encountered the same in our forum & turned out to be vBulletin bug.
@natong
It would be better if you put all those long filenames inside CODE tag.
Click to expand...
Click to collapse
Could you adjust more width and unlimit height for CODE tag ?
Currently it limit to display only 10-20 lines height with scrollbar.
@natong
Sorry, I can't help you with that. But its indeed better to get a CODE window without any horizontal scrollbar.
I known how to post long word now.
1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890

Is this possible using NFC tags?

Hi all,
I'm new to this forum. I registered here because I'm looking into NFC tags to try and create a certain project... So I would like to pick your brains to see if what I 'm looking to do is possible and if so what it would take...
I'm basically looking if I can use NFC tags in a mentalist effect as I'm into magic as a form of entertainment.
I would like to apply NFC tags to a bunch of small items that are displayed in front of me, all within range of my phone (or if need be another NFC reader). Then, while I am not looking, I would like one of my spectators to pick up any object they choose so the rest of the audience can also clearly see what object has been chosen. Yet by doing that, the chosen object would go out of range for the NFC reader. Obviously the spectator would then place the object back where it was. he or she would also be allowed to slightly move all other objects so it wouldn't be obvious which one was picked, as only one object is not in the exact same spot it started in...
I was hoping that there is a way for an NFC reader to scan multiple NFC tags in a reasonable amount of time and then also detect which tag isn't there anymore when the spectator shows the chosen object to the audience. Because that would then give me the chosen object. (the way I see it with my very limited knowledge by scanning all NFC tags within range and comparing that to a database that holds all tags that should be there. This should result in one that's missing)
So, is the above possible? Can NFC technology be used to scan a known library of tags and then identify the single tag that is missing?
If so: what are the limits? How many tags can be scanned let's say within 30 seconds? (like 5, or 50 or 100?) I truly have no idea.
What reader and tags would I need? How would I be able to have the NFC app tell me what tag is missing? Can this be an audio message I can receive through an earpiece?
What would be the maximum area all remaining objects should be in for the reader to be able to pick all of them up?
Is there a minimum distance needed between the tags to be able to read all individual tags or can they be very close together?
Any other constraints I missed?
Thanks a lot for letting me know,
Kind regards,
Peter

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