Proxmark3 community

eskizle

Contributor

Registered: 2011-07-18

Posts: 26

data plot - ASK/FSK/PSK

When reading LF card with the proxmark after getting samples 'data samples X" we can have a graphical view of the wave capture.

I'm wondering what is the Y on the graph. because i'm unable to distinguish ASK,FSK,PSK or other on the graph.
On many examples, what seems to be ASK to me, is FSK in reality...

For example:

the first graph is ASK and the second is FSK...

While FSK is:

Does someone could light me on ?

holiman

Contributor

Registered: 2013-05-03

Posts: 566

Re: data plot - ASK/FSK/PSK

Here's a pretty good blog post about LF modulation, in case you haven't seen it: http://adamsblog.aperturelabs.com/2013/ … fined.html

quelqun

Member

Registered: 2014-04-03

Posts: 4

Re: data plot - ASK/FSK/PSK

Here's a pretty good blog post about LF modulation, in case you haven't seen it: http://adamsblog.aperturelabs.com/2013/08/rfidler-open-source-software-defined.html

I've read the article but something is strange;

Take a look at this (quoted in the article):

For fsk, which correspond to the second image -> HID PROX
But with other sources: http://en.wikipedia.org/wiki/Frequency-shift_keying it's not this.

So, like eskizle i'm lost.

Where is the trap ?

Thanks!