Good candidate for conversion? Methinks not - or perhaps yes :)

Amal, here’s the inside of my bus card, seen against a 1.5 kW projector shining through it. The blob on the upper right (dim. 8.1 x 5.3 mm) is a DESfire EV1, and the antenna goes all around the card (i.e. it’s not a mini card thing).

Does that tell you anything about the chances of converting it?

Ofc just an unenducated guess but there is a flexDF implant so… methinks yes.

If I remember correctly amal can do these things but prefers to add his own antenna as its more reliable I.e. antennas can get damaged during disassembly.

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Yes I also assumed it will be a typical wedge then.

I know you are specifically asking Amal and No real point answering you since you will wait for Amals reply anyway
, however I may be able to help a little… :pinching_hand: since I have sent him 2 cards for conversion.

For what it's worth
  • One of mine was also a DESFire EV1 transport card
  • The dimensions appear to be the same
  • If it has “wings” it will make attaching the antenna viable, it is hard to discern them in your image but it looks like it to me
  • NXPs TagInfo will return 17pF capacitance which is suitable for Amals antennas

So in my opinion YES looks viable.

Send it to him as is, not like this idiot who sent him the exposed chip

Did your transport authorities get back to you or are you just getting your ducks lined up ?
:duck::duck::duck: :gun:

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Just a little more confirmation

Not exactly a micrometer but close enough


I know, you know what to expect, but here you go anyway


Good candidate for conversion? Methinks not SO

There is absolutely no guarantee that this here chip has the right capacitance for Amal’s antenna. It’s not even the same packaging.

Nevermind - see below

It’s not a matter of preference: either this chip will play ball with Amal’s wedge antenna and I’ll implant it, or it won’t and I most certainly won’t implant a full-size antenna :slight_smile:

Oh yeah, I clean forgot about that.

My Taginfo says the chip is a MF3ICD41, capacitance 17 pF.

Well that seems to be good news then. Thanks!

No probs
I think that is a standard response from the app rather than measured, but yeah I would be pretty confident to get it in the mail to Amal, although I’m sure he will be along in a few hours to confirm for ya all proper like :+1:

Haha, :slightly_smiling_face: I just saw your Thread name change !

I guess there’s no guarantee. But maybe is better than forget it.

Sorry, I am filling up your thread, I just checked my TagInfo history and My Transport chip I sent to Amal was identical to yours

Mine was viable for conversion, It did come out of a keyfob rather than full sized card like yours, and My antenna was rather shitty, but that’s the antenna not the chip.

So more POTENTIAL good news for you

I think it’s likely this can be converted. Amal has a bunch of antennas on hand, most of which are tuned for common NXP input capacitances like 17pF. Then it would just come down to how easy it is to dissolve the card and what package/condition the chip is in.

Not sure how easily it’ll dissolve in acetone, but one thing is certain: the plastic is kind of crap. I held it 15 seconds tops in front of the projector, it got barely warm, and that was enough to warp the shit out of it. I straightened it out, but now it feels like it has lost half of its structural strength.

It would not survive one hours on a hot dashboard in the middle of summer - but that doesn’t seem to be a very common problem in Finland :slight_smile:

the df ev1 package is much smaller than a mob packaged IC like @Pilgrimsmaster showed… so my concern is that it is potted silicon instead of a mob package… that would be a very difficult thing to convert.

It might be. I was concerned about that when I saw that the blob in the picture doesn’t look very square.

I’m curious though: even if it’s potted, it does have two leads coming out of it. Couldn’t you solder the antenna onto them? Or is it too delicate?

technically yes but those wires are often laid down and welded by robot, extremely fragile, and coated in enamel which makes getting a reliable electrical connection to them very difficult.

This is my Transport Keyring fob. EV1

Pretty sure mine was 8x5mm


This isnt very scientific, but I used a standard access card for scale and lay it on Roscos chip shillouette and a ruler.

It also appears to be 8x5mm…

not sure if it helps

Okay. Hmm…

So is it worth giving it a whirl do you think, or does it look like a lost cause to you?

yeah dissolve it… see what’s in there… if you don’t send it you can just tape it with packing tape to a business card or something and keep using it as is :wink:

Oh okay. I thought I had read somewhere that you’d rather people didn’t send you dissoved chips, and you’d rather do it yourself.

Right, I’ll do that. But perhaps I’ll order a backup transit card first: if I fuck up, I won’t be able to board a bus no more, as they don’t take cash :slight_smile:

yeah that’s true for known situations, but this is an unknown and rather than you waste $ sending to me to find out it’s not going to work… I figured you are meticulous enough to get it done without damaging the thing.

good plan