I'm new on this forum and newbie in rifd/mifare stuff. I was looking for cheap rfid reader because i have skipass card which i want to break (i hope this is mifare card). I checked bill materials and the most expensive parts are uC and FPGA. I was looking for cheaper alternative and here are my questions to developers:
Can i use smaller fpga chip? For example ColdRunner-II - XC2C64A-7VQG100C ( 64 macrocellls, 100pins). It's 3 times cheaper than spartan-II, also I only need circuit for 13.56MHz RFID so maybe i can use fpga in smaller package and with less amount of macrocells, like XC2C64A-7PCG44C (64macrocells, PLCC44) or even XC2C32-6PC44C (32macrocells, PLCC44)?
MCU - I found cheaper one with the same or better features, Cortex-M3 STM32F107RCT6, with 256kB flash, 64kB and running up to 72MHz. Also if i don't need big flash and ram, i can use chip with smaller flash/ram which is few times cheaper than AT91.
Also i was looking for the cheapest solution (as i wrote, i have card and i can use longer attack), maybe you know any of them?
Thx for response
Of course you can do it, but you will need do modify your PCB. Oh, you will also need to modify thousands of code lines. Maybe you will build PM3_voldi_edition. But finally you will save your $10 on fpga and arm. BTW, I thought that the most expensive part is PCB, it is 4-layer.
According to bill materials xls file, without PCB, FPGA and ARM cost almost 40% of price for all parts, if it's possible to make it cheaper, why don't do that? Maybe with ARM it can be hard (differents in architecture and registers) and not effective, but cheaper fpga costs 3$, and i think you don't need to make many changes in code. I'll look on PCB layout because maybe it's possible to make it 2-layers. I'm not such a rich like you and i just want to build "lite" version, becaue i don't need every features from PM3.
He is not saying that you can't do it, just that you'll have to spend a lot of time on doing it.
Maybe is worth for you to take a look at the Proxmark3 version with LCD (is in the files repository).
It uses a 2-layer PCB and a more common FPGA (although it may be also expensive as it has more capacity).
The schematic has been simplified and it would cost less if you omit the LCD and use the 256K CPU.
On the other hand, I'm having troubles to make the Mifare cards run on it, so it may have some bug, but you can use as an start point if you decide to build your own.
The CPU sources are written in C, so they should be easy to port (as long as your choosen CPU provide the required resources), and the PFGA is written in VHDL, so just compile for your choosen FPGA and look if the design fits (don't forget to edit the constraints file to specify your choosen pin assignment).
Thx for information Cex! I'll look on that, maybe i'll be able to fit it for smaller fpga (i don't need to use 125kHz). Also when i was looking for cheap mifare reader and i found TRH031M ( http://download.maritex.com.pl/pdfs/wi/TRH031M-Data.pdf ) in farnell. Also i have now for few days development board with this chip and i'll try to break my skipass card with some method...
I was looking for cheap rfid reader because i have skipass card which i want to break (i hope this is mifare card).
For mifare another cheap sollution is libnfc supported devices. BTW mine skipasses are ID-only EM-Marines and ISO 15693 cards from Philips.