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#1 2015-02-02 17:17:38
- asper
- Contributor
- Registered: 2008-08-24
- Posts: 1,409
PCF Modulation
I would like to point out this other not-so-common coding modulation used in a minor % of tags (ex. PCF for programming-only commands): Pulse Position Modulation. If someone wants to investigate, it will be great to have ppm supported in PM3.
PCF uses an ASK modulation but the coding (how to encode 0s and 1s) is determined by CDP for reading (Conditioned Diphase) and PPM (Pulse Position Modulation) for writing; PCF reading is already implemented in PM3 but writing is not. Here are the specs:
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#2 2015-04-07 23:15:25
- iZsh
- Contributor
- Registered: 2010-01-02
- Posts: 95
Re: PCF Modulation
I rewrote this code long time ago and actually implemented the programming mode. Unfortunately I never got the time to actually commit it (this is the blog post part3 I said I was going to write long time ago on f0f's blog). Maybe this summer, hopefully ;-)
BTW, as a side comment, the programming mode for the PCF IC doesn't actually really work properly/reliably with the proxmark because the antenna signal is weak, and the pulse length is limited by the hardware design. It is therefore near impossible to have short sharp pulses as required by the programming mode for the PCF.
I'll let you know once I have time to commit the code and write this damn blog post part3
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#3 2015-04-07 23:21:34
- iceman
- Administrator
- Registered: 2013-04-25
- Posts: 9,538
- Website
Re: PCF Modulation
I think Marshmellow has an Condition Diphase, Biphase1a or something, in the latest LF. Which I suppose will come in handy if we want to remake the PCF demods / functionalities or implement more tags
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#4 2015-04-08 13:07:40
- asper
- Contributor
- Registered: 2008-08-24
- Posts: 1,409
Re: PCF Modulation
I rewrote this code long time ago and actually implemented the programming mode. Unfortunately I never got the time to actually commit it (this is the blog post part3 I said I was going to write long time ago on f0f's blog). Maybe this summer, hopefully ;-)
BTW, as a side comment, the programming mode for the PCF IC doesn't actually really work properly/reliably with the proxmark because the antenna signal is weak, and the pulse length is limited by the hardware design. It is therefore near impossible to have short sharp pulses as required by the programming mode for the PCF.
I'll let you know once I have time to commit the code and write this damn blog post part3
Thank you for your previous work iZsh ! It will be great to have your code updated !!
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