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#1 2009-01-20 07:34:12

shinechou
Contributor
Registered: 2008-10-20
Posts: 35

strange antenna problem with diff. PM3-workspace

so happy I can run my pm3 with d18c7db's workspace ("20081121_prox.zip" and ""20081211_prox.zip), but I find a strange problem, that is, if i use the "2008.09.17-armpgm-ebuller-proxmark3-image.S19" to flash my pm3 and exec. "tune" command then show "HF antenna @  127 mA", but it'll show "HF antenna @  44 mA" if i use the "bootrom-merged.s19" compiled by ur workspace, and the graph are diff. when I exec. "plot" command with the diff bootroms but the same 14443a card and the same atenna, I'm a noob and don't know which is better (127mA or 44mA)? why will be like this?

pls help me! thx a milllion in advance!

Kindly regards.
Ryan

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#2 2009-01-20 08:05:03

d18c7db
Contributor
Registered: 2008-08-19
Posts: 292

Re: strange antenna problem with diff. PM3-workspace

The reason tune gives different values is because the original ebuller code calculates the HF value using 130pF as the capacitor value on the HF antenna but in fact the latest revision of the board actually uses a 50pF capacitor so the calculations with my version of the code take that into account to display the correct value. Look at armsrc\appmain.c in the section:

void MeasureAntennaTuning(void)
{
// Impedances are Zc = 1/(j*omega*C), in ohms
#define LF_TUNING_CAP_Z    1273    //  1 nF @ 125   kHz
#define HF_TUNING_CAP_Z    235    // 50 pF @ 13.56 MHz

Not sure why your plot graphs are different between versions, but since your tune values for HF are so low I assume you don't have a properly working HF antenna so you're probably picking up noise. The HF value for my antenna using tune is in the 11000mV range (ie around 11 volts), see the output of my tune command in this post

I've tested my latest code on both HF and LF cards and I can read either just fine.

Last edited by d18c7db (2009-01-20 08:06:57)

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#3 2009-01-20 11:31:58

shinechou
Contributor
Registered: 2008-10-20
Posts: 35

Re: strange antenna problem with diff. PM3-workspace

thx a ton for ur help at first! I'll re-build my atenna and then try, but I'd ask for ur help about snoop, when I exec. "hi14asnoop" cmd, and then run "librfid-tool -s" (used for OpenPCD reader) to scan a 14443a card, then press the button of pm3 to stop snoop, and then exec. hi14alist, but the pm3 restart soon and no further info, why'll be like this? my snoop-process right or wrong? 

thx in advance!

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#4 2009-01-20 23:02:59

d18c7db
Contributor
Registered: 2008-08-19
Posts: 292

Re: strange antenna problem with diff. PM3-workspace

If the PM3 restarts it means it crashed and the watchdog has rebooted it. Have you flashed all three components of the new version software, the bootloader, the FPGA image and the osimage? Does it do the same when running ebuller. You'll need to supply us with more information.

Also have you fixed your antenna problem, you should get much more than 127mV on HF when running tune, it should be somehwere in the several thousands of mV.

I've just done a test with my latest code (20081211) see below:

>> Connected to device
> tune
# LF antenna @  22 mA / 28601 mV [1273 ohms] 125Khz
# LF antenna @  21 mA / 25109 mV [1187 ohms] 134Khz
# HF antenna @  40 mA / 10571 mV [235 ohms] 13.56Mhz
> hi14asnoop
#db# cancelled_a
#db# 00000062, 00000000, 00000000

#db# 00000020, 00000097, 00000002

> hi14alist
recorded activity:
 ETU     :rssi: who bytes
---------+----+----+-----------
 +      0:    :     26    
 +   5143:    :     26    
 +   1440:    :     93  20    
 +   5014:    :     e0  50  bc  a5    
 +  61295:    :     26    
 +   5143:    :     26    
 +   1440:    :     93  20    
 +   3462:    :     93  70  08  e7  57  91  29  b7  d3    
 +   1552:    :     e0  50  bc  a5    
 +  17094:    :     02  00  a4  04  00  07  d4  10  00  00  03  00  01  cd  0d  00  00    
 +  18086:    :     02  90  4c  00  00  04  57  c6  00  00

Last edited by d18c7db (2009-01-21 22:50:03)

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#5 2009-01-21 03:48:17

shinechou
Contributor
Registered: 2008-10-20
Posts: 35

Re: strange antenna problem with diff. PM3-workspace

hi d18c7db,

so great, I can run the snoop function correctly with ur help, many thanks! u're awesome and  warm-hearted!

that's the log with ur latest code (20081211) and the newer antenna, I think the antenna is the keypoint for me, I use a coiled silver wire to make the old antenna, but it can't work correctly for me, according to ur suggestions, I use some bared copper wire to re-build the newer atenna and then like a charm.

I'm confused that it hasn't the "response" data in the log, I mean I exec. a "Get Challenge" APDU command ("0084000008") to get 8-bytes data from the card and I can find the 8-bytes challenge response in the output window of "MifareWnd" tool (provided by NXP), that is
"Send = 00 84 00 00 08
Receive = 19 79 60 A2 D5 B6 FB 80 90 00", I cant find something like "19 79 60 A2 D5 B6 FB 80 90 00" in the log of pm3, why? maybe the buffer of pm3 is incomplete?


anyway, thx a ton for ur patient help!

>> Started prox, built Jan 20 2009 13:51:54
>> Connected to device
> tune
# LF antenna @   0 mA /     0 mV [1273 ohms] 125Khz
# LF antenna @   0 mA /   134 mV [1187 ohms] 134Khz
# HF antenna @  52 mA / 12375 mV [235 ohms] 13.56Mhz
> hi14asnoop
#db# cancelled_a
#db# 00000032, 00000000, 00000008

#db# 00000020, 00000077, 00000002

> hi14alist
recorded activity:
 ETU     :rssi: who bytes
---------+----+----+-----------
 +      0:    :     26    
 +     74:   0: TAG 01    
 +    710:    :     93  20    
 +     74:   0: TAG ec    
 +    112:   0: TAG 32    
 +     78:   0: TAG 03!   
 +   1288:    :     93  70  26  53  01  67  13  d5  22    
 + 919963:    :     e0  80  31  73    
 +   1466:   0: TAG 00!   
 +2568402:    :     02  00  84  00  00  08  2f  ec

Last edited by shinechou (2009-01-22 10:22:11)

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#6 2009-01-21 09:11:44

doob
Member
Registered: 2008-07-21
Posts: 15

Re: strange antenna problem with diff. PM3-workspace

Hi, your tag responses are incomplete (as you already know) from the above 14443a trace. I have this problem too, I guess it may be to do with how you orientate the proxmark antenna, tag and reader. The reader signal is generally much stronger.

Try taking the same trace/snoop a few times, changing the position of reader/card/proxmark and checking the output.

edit: Thinking about it, I have not yet been able to capture tag responses with hi14asnoop, I generally get the reader OK but all the tag transmissions are either truncated or corrupt.

Last edited by doob (2009-01-21 09:19:34)

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#7 2009-01-21 11:35:12

shinechou
Contributor
Registered: 2008-10-20
Posts: 35

Re: strange antenna problem with diff. PM3-workspace

hi doob,

thx for ur suggestions! I'd changed the position of reader/card/proxmark as u said, but can't get complete snoop yet, so strange!

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#8 2009-01-21 22:38:54

d18c7db
Contributor
Registered: 2008-08-19
Posts: 292

Re: strange antenna problem with diff. PM3-workspace

Yeah your output doesn't look clean, you should not have exclamation marks (crc error).

What I found is that the orientation of the antenna is critical, for example I sometimes get output like this:

> hi14asnoop
#db# cancelled_a
#db# 00000049, 00000000, 00000000

#db# 00000020, 00000042, 00000026

> hi14alist
recorded activity:
 ETU     :rssi: who bytes
---------+----+----+-----------
 +      0:   0: TAG fb    
 +    112:   0: TAG 02    
 + 969544:   0: TAG 01    
 +     48:   0: TAG 0f!   
 +  36260:   0: TAG df! df! 1f  ff  e5! cd! 1f      !crc
 +    536:   0: TAG 01

But then if I reposition the antenna by rotating it 90 degrees I get clean capture like so:

> hi14asnoop
#db# cancelled_a
#db# 00000063, 00000000, 00000000

#db# 00000020, 00000148, 00000002

> hi14alist
recorded activity:
 ETU     :rssi: who bytes
---------+----+----+-----------
 +      0:    :     26    
 +   5143:    :     26    
 +   1440:    :     93  20    
 +   3462:    :     93  70  08  b6  cc  f4  86  d5  fc    
 +   1552:    :     e0  50  bc  a5    
 +  49438:    :     26    
 +   5144:    :     26    
 +   1438:    :     93  20    
 +   3464:    :     93  70  08  b9  0d  0a  b6  f1  c9    
 +   1552:    :     e0  50  bc  a5    
 +  16239:    :     02  00  a4  04  00  07  d4  10  00  00  03  00  01  cd  0d  00  00    
 +  18925:    :     02  90  4c  00  00  04  57  c6  00  00

Try playing with your antenna position until you get some success, I know the current code seems to work for me without problems so all things being equal it should work for you too, if not it's probably something related to your antenna or its placement. The capture buffer in the current code is almost 2000 bytes so you should be able to capture heaps of traffic before you run out of buffer.

Last edited by d18c7db (2009-01-21 22:50:27)

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#9 2009-01-22 01:35:23

doob
Member
Registered: 2008-07-21
Posts: 15

Re: strange antenna problem with diff. PM3-workspace

hi d18c7db,

I noticed in your second hi14asnoop output, there are only reader transmissions there, no tag responses. Perhaps the re-orientation on the antenna resulted in the proxmark not picking up any signal from the tag.

I think this is what I seem to get when trying the snoop function although more often than not I will get a few corrupt TAG reponses in the hi14alist output as well.

+   1584:    :     52    
 +   1136:    :     93  20    
 +   2464:    :     93  70  88  04  33  30  8f  92  d8    
 +    824:    :     95  20    
 +      8:   0: TAG 02    
 +   2448:    :     95  70  51  48  1d  80  84  12  38    
 +     47:   0: TAG 00!   
 +   1273:    :     e0  21  b2  c7    
 +    650:   0: TAG 00!   
 +   4568:   0: TAG 00!   
 +  38726:    :     d1  11  00  8e  fc    
 +   2080:    :     0a  01  5a  58  48  00  c6  d1    
 +   2112:    :     0b  01  0a  00  b9  31    
 + 180135:    :     0a  01  af  d0  54  f6  77  27  f2  a7  7b  b8  d5  83  e2  c5  0f  e5  cd  7d  92    
 +    228:   0: TAG 01    
 +    135:   0: TAG 00!   
 +  61189:    :     0b  01  bd  00  00  00  00  08  00  00  32  44    
 +  39967:    :     ca  01  f3  38    
 +   1408:    :     50  00  57  cd    
 +  24814:   0: TAG 01    
 +   5554:   0: TAG 00!   
 +   3576:   0: TAG 00!

thx

doob

Last edited by doob (2009-01-22 01:39:37)

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#10 2009-01-22 07:18:59

shinechou
Contributor
Registered: 2008-10-20
Posts: 35

Re: strange antenna problem with diff. PM3-workspace

the newest log, but incomplete yet!

>> Started prox, built Jan 20 2009 13:51:54
>> Connected to device
> tune
# LF antenna @   0 mA /     0 mV [1273 ohms] 125Khz
# LF antenna @   0 mA /     0 mV [1187 ohms] 134Khz
# HF antenna @  54 mA / 12826 mV [235 ohms] 13.56Mhz
> hi14asnoop
#db# cancelled_a
#db# 00000033, 00000000, 00000008

#db# 00000020, 0000009b, 00000002

> hi14alist
recorded activity:
 ETU     :rssi: who bytes
---------+----+----+-----------
 +      0:    :     26    
 +     64:   0: TAG 04  00    
 +    720:    :     93  20    
 +     64:   0: TAG 7c  3c  5d  d3  ce    
 +   1488:    :     93  70  7c  3c  5d  d3  ce  24  46    
 +     64:   0: TAG 08  b6  dd    
 +1170760:    :     e0  80  31  73    
 +     64:   0: TAG 04    
 +9615776:    :     93  70  00  00  00  00  00  9c  d9    
 +2209704:    :     93  20    
 +58529032:    :     02  00  84  00  00  08  2f  ec    
 +   7657:   0: TAG 01

Last edited by shinechou (2009-01-22 10:22:53)

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#11 2009-01-22 08:02:40

shinechou
Contributor
Registered: 2008-10-20
Posts: 35

Re: strange antenna problem with diff. PM3-workspace

so, the position and orientation of the atenna of PM3 is the keypoint, congratulations, I'd got the complete snoop as following,

> tune
# LF antenna @   0 mA /     0 mV [1273 ohms] 125Khz
# LF antenna @   0 mA /   134 mV [1187 ohms] 134Khz
# HF antenna @  55 mA / 13019 mV [235 ohms] 13.56Mhz
> hi14asnoop
#db# cancelled_a
#db# 0000001b, 00000000, 00000008

#db# 00000020, 00000027, 00000002

> hi14alist
recorded activity:
 ETU     :rssi: who bytes
---------+----+----+-----------
 +      0:    :     02  00  84  00  00  08  2f  ec    
 +   3008:   0: TAG 02  9b  47  1a  b0  c0  8a  5b  fa  90  00  be  8e

Last edited by shinechou (2009-01-22 10:23:25)

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#12 2009-01-22 09:06:58

d18c7db
Contributor
Registered: 2008-08-19
Posts: 292

Re: strange antenna problem with diff. PM3-workspace

Doob your are correct. I didn't look closely at the output before posting, I just saw I was getting data, but didn't notice I wasn't getting TAG data.

I was suffering from the same problem I was advising shinechou about, ie antenna orientation. By repositioning my antenna I got a proper capture as below. I haven't analysed the data in detail but the anticollision phase looks correct (both PCD and PICC sides) and in the data received from the card I can see the serial number 0x130542 of my test card and the dollar balance of $20.00 = 2000 = 0x07d0 (last line)

>> Connected to device
> hi14asnoop
#db# cancelled_a
#db# 0000006d, 00000000, 00000000

#db# 00000020, 00000146, 00000002

> hi14alist
recorded activity:
 ETU     :rssi: who bytes
---------+----+----+-----------
 +      0:    :     26    
 +   5143:    :     26    
 +     64:   0: TAG 04  00    
 +   1304:    :     93  20    
 +     64:   0: TAG 08  aa  c9  52  39    
 +   3470:    :     93  70  08  aa  c9  52  39  ae  27    
 +     64:   0: TAG 20  fc  70    
 +   1488:    :     e0  50  bc  a5    
 +     88:   0: TAG 08  57  80  02  01  10  00  09  94  da    
 +  55266:    :     26    
 +   5144:    :     26    
 +     64:   0: TAG 04  00    
 +   1302:    :     93  20    
 +     64:   0: TAG 08  98  a5  7d  48    
 +   3472:    :     93  70  08  98  a5  7d  48  31  30    
 +   1552:    :     e0  50  bc  a5    
 +     88:   0: TAG 08  57  80  02  01  10  00  09  94  da    
 +  17238:   0: TAG 02! 6f  31  b0! 2f! 00! 10! 01! 02! 10! 10! 00  00  00  13! 05  42  00  00  01! 30  54! 20! 08  06  17  20  28  06  16  01  00  00  00  75  30  00  01  00  00  00  00  00  00  00  00  00  00  00  00  00  00  90  00  88  23    
 +  12766:    :     02  90  4c  00  00  04  57  c6  00  00    
 +    472:   0: TAG 03  00  00  07  d0  90  00  3a  ee

Last edited by d18c7db (2009-01-22 09:15:18)

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#13 2009-01-22 09:25:08

TomBu
Contributor
From: Delft, The Netherlands
Registered: 2008-10-27
Posts: 55
Website

Re: strange antenna problem with diff. PM3-workspace

Hi everyone,


Great that you guys found out that the orientation is so important.
Hence it should be documented well, so others can learn from it.
Would anyone care to show, with a small drawing or picture, the orientation that's working for him /her?


Cheers,
Tom

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#14 2009-01-22 21:09:15

d18c7db
Contributor
Registered: 2008-08-19
Posts: 292

Re: strange antenna problem with diff. PM3-workspace

What works for me is the plane of the PM3 antenna is right next to the plane of the RFID card but the long side of the RFID card is rotated about 45 degrees relative to the long side of the antenna. If you look here at the first two pictures, where the green wire rectangle is the PM3 antenna you get an idea of the setup.

Later in that post I show a different antenna that I built but the actual positioning of the card remains the same. I imagine that if others have made different types of antennas, ie circular, they would need to experiment with what works best for them.

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#15 2009-01-23 09:17:07

shinechou
Contributor
Registered: 2008-10-20
Posts: 35

Re: strange antenna problem with diff. PM3-workspace

very same as mine setup!

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#16 2009-01-23 10:09:15

TomBu
Contributor
From: Delft, The Netherlands
Registered: 2008-10-27
Posts: 55
Website

Re: strange antenna problem with diff. PM3-workspace

OK!

Thanks for the feedback.

Cheers,
Tom

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