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FIX: This commit fixes the broken LF since I change the spindelay calls. The original problem is that spindelayus calls is incremented with21.3us each step, making it very hard to find exact timings found in the datasheets for T55x7, HID etcetc. When @marshmellow and I looked into this 2014, I had this on my back of my mind but forgot it since I didn't know how the source code / pm3 worked. This behavior in spindelayus has given the bit-period for ON/OFF measured in (us) very hard to find. Its kind of magic that it worked so far so good. Well until I started to look into the "hf legic" bitbanging ASK ON/OFF keying and that one needs a much more precis timer. Same goes for the PCF7931 code.

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I've added a precise timer in the new files ticks.c and moved some older stuff from util.c to have a solid base for this.
UNTESTED,  and the timings measured for t55x7 in lfops.c and other parts has not been adjusted to this "correct" timer.
This commit is contained in:
iceman1001 2016-09-23 16:35:26 +02:00
commit 24c49d36ba
4 changed files with 67 additions and 89 deletions
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59
armsrc/lfsampling.c
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@ -6,17 +6,11 @@
// Miscellaneous routines for low frequency sampling.
//-----------------------------------------------------------------------------
#include "proxmark3.h"
#include "apps.h"
#include "util.h"
#include "string.h"
#include "usb_cdc.h" // for usb_poll_validate_length
#include "lfsampling.h"
sample_config config = { 1, 8, 1, 95, 0 } ;
void printConfig()
{
void printConfig() {
Dbprintf("LF Sampling config: ");
Dbprintf(" [q] divisor: %d ", config.divisor);
Dbprintf(" [b] bps: %d ", config.bits_per_sample);
@ -37,8 +31,7 @@ void printConfig()
* @brief setSamplingConfig
* @param sc
*/
void setSamplingConfig(sample_config *sc)
{
void setSamplingConfig(sample_config *sc) {
if(sc->divisor != 0) config.divisor = sc->divisor;
if(sc->bits_per_sample != 0) config.bits_per_sample = sc->bits_per_sample;
if(sc->decimation != 0) config.decimation = sc->decimation;
@ -51,8 +44,7 @@ void setSamplingConfig(sample_config *sc)
printConfig();
}
sample_config* getSamplingConfig()
{
sample_config* getSamplingConfig() {
return &config;
}
@ -67,8 +59,7 @@ typedef struct {
* @param stream
* @param bit
*/
void pushBit( BitstreamOut* stream, uint8_t bit)
{
void pushBit( BitstreamOut* stream, uint8_t bit) {
int bytepos = stream->position >> 3; // divide by 8
int bitpos = stream->position & 7;
*(stream->buffer+bytepos) |= (bit > 0) << (7 - bitpos);
@ -83,8 +74,7 @@ void pushBit( BitstreamOut* stream, uint8_t bit)
* 0 or 95 ==> 125 KHz
*
**/
void LFSetupFPGAForADC(int divisor, bool lf_field)
{
void LFSetupFPGAForADC(int divisor, bool lf_field) {
FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
if ( (divisor == 1) || (divisor < 0) || (divisor > 255) )
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
@ -101,6 +91,9 @@ void LFSetupFPGAForADC(int divisor, bool lf_field)
SpinDelay(50);
// Now set up the SSC to get the ADC samples that are now streaming at us.
FpgaSetupSsc();
// start a 1.5ticks is 1us
StartTicks();
}
/**
@ -118,8 +111,7 @@ void LFSetupFPGAForADC(int divisor, bool lf_field)
* @param silent - is true, now outputs are made. If false, dbprints the status
* @return the number of bits occupied by the samples.
*/
uint32_t DoAcquisition(uint8_t decimation, uint32_t bits_per_sample, bool averaging, int trigger_threshold,bool silent)
{
uint32_t DoAcquisition(uint8_t decimation, uint32_t bits_per_sample, bool averaging, int trigger_threshold,bool silent) {
//bigbuf, to hold the aquired raw data signal
uint8_t *dest = BigBuf_get_addr();
uint16_t bufsize = BigBuf_max_traceLen();
@ -210,12 +202,10 @@ uint32_t DoAcquisition(uint8_t decimation, uint32_t bits_per_sample, bool averag
* @param silent
* @return number of bits sampled
*/
uint32_t DoAcquisition_default(int trigger_threshold, bool silent)
{
uint32_t DoAcquisition_default(int trigger_threshold, bool silent) {
return DoAcquisition(1,8,0,trigger_threshold,silent);
}
uint32_t DoAcquisition_config( bool silent)
{
uint32_t DoAcquisition_config( bool silent) {
return DoAcquisition(config.decimation
,config.bits_per_sample
,config.averaging
@ -223,11 +213,10 @@ uint32_t DoAcquisition_config( bool silent)
,silent);
}
uint32_t ReadLF(bool activeField, bool silent)
{
if (!silent) printConfig();
uint32_t ReadLF(bool activeField, bool silent) {
if (!silent)
printConfig();
LFSetupFPGAForADC(config.divisor, activeField);
// Now call the acquisition routine
return DoAcquisition_config(silent);
}
@ -235,8 +224,7 @@ uint32_t ReadLF(bool activeField, bool silent)
* Initializes the FPGA for reader-mode (field on), and acquires the samples.
* @return number of bits sampled
**/
uint32_t SampleLF(bool printCfg)
{
uint32_t SampleLF(bool printCfg) {
return ReadLF(true, printCfg);
}
/**
@ -253,23 +241,22 @@ uint32_t SnoopLF() {
**/
void doT55x7Acquisition(size_t sample_size) {
#define T55xx_READ_UPPER_THRESHOLD 128+60 // 60 grph
#define T55xx_READ_LOWER_THRESHOLD 128-60 // -60 grph
#define T55xx_READ_TOL 5
#define T55xx_READ_UPPER_THRESHOLD 128+40 // 60 grph
#define T55xx_READ_LOWER_THRESHOLD 128-40 // -60 grph
#define T55xx_READ_TOL 2
uint8_t *dest = BigBuf_get_addr();
uint16_t bufsize = BigBuf_max_traceLen();
if ( bufsize > sample_size )
bufsize = sample_size;
uint16_t i = 0;
uint8_t curSample = 0, lastSample = 0;
uint16_t i = 0, skipCnt = 0;
bool startFound = false;
bool highFound = false;
bool lowFound = false;
uint8_t curSample = 0;
uint8_t lastSample = 0;
uint16_t skipCnt = 0;
while(!BUTTON_PRESS() && !usb_poll_validate_length() && skipCnt < 1000 && (i < bufsize) ) {
WDT_HIT();
if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
@ -301,7 +288,7 @@ void doT55x7Acquisition(size_t sample_size) {
// skip until first high samples begin to change
if (startFound || curSample > T55xx_READ_LOWER_THRESHOLD+T55xx_READ_TOL){
if (startFound || curSample > T55xx_READ_LOWER_THRESHOLD + T55xx_READ_TOL){
// if just found start - recover last sample
if (!startFound) {
dest[i++] = lastSample;