Proxmark

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Upgrading ELECHOUSE Proxmark3 Easy V3 to 512k

The popular Proxmark3 Easy has an at91sam7s256 with only 256k and e.g. it's already about 83% full with the current iceman firmware.
So I decided to attempt an upgrade.

at91sam7s512 is about [15€ on http://fr.farnell.com/atmel/at91sam7s512b-au/micro-32-bits-arm7-512k-flash/dp/1972051 Farnell].

The steps I followed to desolder and solder the new chip are basically the same as seen on this youtube video:

  • heating the chip with my desoldering station
  • removing the chip with a small suction pen
  • putting flux on the pads
  • cleaning the pads with desoldering wire
  • putting the new chip and soldering some pins to lock it in place (look for aligning the small dot on the correct corner)
  • putting flux on the pins
  • putting solder on the pins, don't be afraid of bridges...
  • removing extra solder with desoldering wire
  • checking carefully for residual solder bridges

And voila.

Note that it's maybe easier to solder the new chip not by using flux+solder+iron but solder flux paste and heating with air gun, as shown in this video...

Then wire your JTAG programmer to the board. Mine is a Segger J-Link.
To make it easier, solder a breakable single-row male curved header.
Choose a curved one so you can leave it in place later and still stack the PM3 daughterboard.

Then using Dupont wires male-female, wire it to the JTAG programmer.

For the J-Link, the pinout is:

  ---------  ---------
 |1917151311 9 7 5 3 1|
 |201816141210 8 6 4 2|
  --------------------

PM3  JLink
---  -----
TMS   7
TDI   5
TDO  13
TCK   9
GND   6
3.3  not connected

I didn't connect the 3v3 because J-Link Vref is 5v so I prefered to power the PM3 over USB while reprogramming it.

To use the J-Link on Debian:

$ apt-get install openocd

Create /etc/udev/rules.d/60-jlink.rules with

ATTRS{idVendor}=="1366", ATTRS{idProduct}=="0101", MODE="664", GROUP="plugdev"