From 4160e32b0ae050383c56529c3d45a62881b52e86 Mon Sep 17 00:00:00 2001
From: Philippe Teuwen <phil@teuwen.org>
Date: Fri, 8 Mar 2019 19:06:55 +0100
Subject: [PATCH 1/2] Replace isNoise by computeSignalProperties and
removeSignalOffset
---
armsrc/lfsampling.c | 7 +--
client/cmddata.c | 66 +++++++++++++-------------
client/cmdlfem4x.c | 11 +++--
client/cmdlft55xx.c | 6 ++-
client/comms.c | 2 +-
common/lfdemod.c | 111 ++++++++++++--------------------------------
common/lfdemod.h | 18 ++++---
7 files changed, 92 insertions(+), 129 deletions(-)
diff --git a/armsrc/lfsampling.c b/armsrc/lfsampling.c
index 96963d389..4b036d088 100644
--- a/armsrc/lfsampling.c
+++ b/armsrc/lfsampling.c
@@ -204,8 +204,9 @@ uint32_t DoAcquisition(uint8_t decimation, uint32_t bits_per_sample, bool averag
dest[0], dest[1], dest[2], dest[3], dest[4], dest[5], dest[6], dest[7]);
}
- // Ensure that noise check is performed for any device-side processing
- isNoise(dest, bufsize);
+ // Ensure that DC offset removal and noise check is performed for any device-side processing
+ removeSignalOffset(dest, bufsize);
+ computeSignalProperties(dest, bufsize);
return data.numbits;
}
@@ -451,4 +452,4 @@ uint32_t doCotagAcquisitionManchester() {
}
}
return sample_counter;
-}
\ No newline at end of file
+}
diff --git a/client/cmddata.c b/client/cmddata.c
index ba3d61156..285b4d189 100644
--- a/client/cmddata.c
+++ b/client/cmddata.c
@@ -1393,15 +1393,13 @@ int CmdHide(const char *Cmd) {
//zero mean GraphBuffer
int CmdHpf(const char *Cmd) {
- int i, accum = 0;
-
- for (i = 10; i < GraphTraceLen; ++i)
- accum += GraphBuffer[i];
-
- accum /= (GraphTraceLen - 10);
-
- for (i = 0; i < GraphTraceLen; ++i)
- GraphBuffer[i] -= accum;
+ uint8_t bits[GraphTraceLen];
+ size_t size = getFromGraphBuf(bits);
+ removeSignalOffset(bits, size);
+ // push it back to graph
+ setGraphBuf(bits, size);
+ // set signal properties low/high/mean/amplitude and is_noise detection
+ computeSignalProperties(bits, size);
RepaintGraphWindow();
return 0;
@@ -1471,12 +1469,15 @@ int getSamples(int n, bool silent) {
GraphTraceLen = n;
}
- //ICEMAN todo
uint8_t bits[GraphTraceLen];
size_t size = getFromGraphBuf(bits);
- // set signal properties low/high/mean/amplitude and is_noice detection
- isNoise(bits, size);
-
+ // TODO now DC removal is done already on device, right ?
+ // removeSignalOffset(bits, size);
+ // push it back to graph
+ // setGraphBuf(bits, size);
+ // set signal properties low/high/mean/amplitude and is_noise detection
+ computeSignalProperties(bits, size);
+
setClockGrid(0, 0);
DemodBufferLen = 0;
RepaintGraphWindow();
@@ -1610,15 +1611,19 @@ int CmdLoad(const char *Cmd) {
fclose(f);
PrintAndLogEx(SUCCESS, "loaded %d samples", GraphTraceLen);
+
+ uint8_t bits[GraphTraceLen];
+ size_t size = getFromGraphBuf(bits);
+ // set signal properties low/high/mean/amplitude and is_noise detection
+ removeSignalOffset(bits, size);
+ // push it back to graph
+ setGraphBuf(bits, size);
+ // set signal properties low/high/mean/amplitude and is_noise detection
+ computeSignalProperties(bits, size);
+
setClockGrid(0,0);
DemodBufferLen = 0;
RepaintGraphWindow();
-
- //ICEMAN todo
- // set signal properties low/high/mean/amplitude and isnoice detection
- uint8_t bits[GraphTraceLen];
- size_t size = getFromGraphBuf(bits);
- isNoise(bits, size);
return 0;
}
@@ -1683,11 +1688,11 @@ int CmdNorm(const char *Cmd) {
}
}
- //ICEMAN todo
- // set signal properties low/high/mean/amplitude and isnoice detection
uint8_t bits[GraphTraceLen];
size_t size = getFromGraphBuf(bits);
- isNoise(bits, size);
+ // set signal properties low/high/mean/amplitude and is_noise detection
+ computeSignalProperties(bits, size);
+
RepaintGraphWindow();
return 0;
}
@@ -1773,11 +1778,11 @@ int CmdDirectionalThreshold(const char *Cmd) {
directionalThreshold(GraphBuffer, GraphBuffer, GraphTraceLen, up, down);
- //ICEMAN todo
// set signal properties low/high/mean/amplitude and isnoice detection
uint8_t bits[GraphTraceLen];
size_t size = getFromGraphBuf(bits);
- isNoise(bits, size);
+ // set signal properties low/high/mean/amplitude and is_noice detection
+ computeSignalProperties(bits, size);
RepaintGraphWindow();
return 0;
@@ -1805,11 +1810,10 @@ int CmdZerocrossings(const char *Cmd) {
}
}
- //ICEMAN todo
- // set signal properties low/high/mean/amplitude and isnoice detection
uint8_t bits[GraphTraceLen];
size_t size = getFromGraphBuf(bits);
- isNoise(bits, size);
+ // set signal properties low/high/mean/amplitude and is_noise detection
+ computeSignalProperties(bits, size);
RepaintGraphWindow();
return 0;
@@ -2063,13 +2067,11 @@ int CmdDataIIR(const char *Cmd){
//iceIIR_Butterworth(GraphBuffer, GraphTraceLen);
iceSimple_Filter(GraphBuffer, GraphTraceLen, k);
- //ICEMAN todo
- // set signal properties low/high/mean/amplitude and isnoice detection
uint8_t bits[GraphTraceLen];
size_t size = getFromGraphBuf(bits);
- isNoise(bits, size);
-
- RepaintGraphWindow();
+ // set signal properties low/high/mean/amplitude and is_noise detection
+ computeSignalProperties(bits, size);
+ RepaintGraphWindow();
return 0;
}
diff --git a/client/cmdlfem4x.c b/client/cmdlfem4x.c
index 6d90e550f..e4909ace9 100644
--- a/client/cmdlfem4x.c
+++ b/client/cmdlfem4x.c
@@ -800,7 +800,7 @@ int EM4x50Read(const char *Cmd, bool verbose) {
uint8_t bits[MAX_GRAPH_TRACE_LEN] = {0};
size_t size = getFromGraphBuf(bits);
- isNoise(bits, size);
+ computeSignalProperties(bits, size);
signal_t *sp = getSignalProperties();
high = sp->high;
@@ -999,9 +999,14 @@ bool downloadSamplesEM(){
PrintAndLogEx(WARNING, "command execution time out");
return false;
}
- setGraphBuf(got, sizeof(got));
- if (isNoise(got, sizeof(got))) {
+ // TODO now DC removal is done already on device, right ?
+ // removeSignalOffset(got, sizeof(got));
+ setGraphBuf(got, sizeof(got));
+ // set signal properties low/high/mean/amplitude and is_noise detection
+ computeSignalProperties(got, sizeof(got));
+ RepaintGraphWindow();
+ if (getSignalProperties()->isnoise) {
PrintAndLogEx(DEBUG, "No tag found");
return false;
}
diff --git a/client/cmdlft55xx.c b/client/cmdlft55xx.c
index 3c7547e34..446e440ce 100644
--- a/client/cmdlft55xx.c
+++ b/client/cmdlft55xx.c
@@ -1330,8 +1330,12 @@ bool AquireData( uint8_t page, uint8_t block, bool pwdmode, uint32_t password )
PrintAndLogEx(WARNING, "command execution time out");
return false;
}
+ // set signal properties low/high/mean/amplitude and is_noise detection
+ removeSignalOffset(got, sizeof(got));
+ computeSignalProperties(got, sizeof(got));
setGraphBuf(got, sizeof(got));
- return !isNoise(got, sizeof(got));
+ RepaintGraphWindow();
+ return !getSignalProperties()->isnoise;
}
char * GetBitRateStr(uint32_t id, bool xmode) {
diff --git a/client/comms.c b/client/comms.c
index 5beaa0adb..f08c5f413 100644
--- a/client/comms.c
+++ b/client/comms.c
@@ -463,7 +463,7 @@ bool GetFromDevice(DeviceMemType_t memtype, uint8_t *dest, uint32_t bytes, uint3
return dl_it(dest, bytes, start_index, response, ms_timeout, show_warning, CMD_FLASHMEM_DOWNLOADED);
}
case SIM_MEM: {
- //UsbCommand c = {CMD_DOWNLOAND_SIM_MEM, {start_index, bytes, 0}};
+ //UsbCommand c = {CMD_DOWNLOAD_SIM_MEM, {start_index, bytes, 0}};
//SendCommand(&c);
//return dl_it(dest, bytes, start_index, response, ms_timeout, show_warning, CMD_DOWNLOADED_SIMMEM);
return false;
diff --git a/common/lfdemod.c b/common/lfdemod.c
index 1fd69d1b9..b9807ff8f 100644
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -47,8 +47,7 @@
//**********************************************************************************************
#define LOWEST_DEFAULT_CLOCK 32
#define FSK_PSK_THRESHOLD 123
-//might not be high enough for noisy environments
-#define NOICE_AMPLITUDE_THRESHOLD 10
+
//to allow debug print calls when used not on dev
//void dummy(char *fmt, ...){}
@@ -76,6 +75,7 @@ static void resetSignal(void) {
signalprop.amplitude = 0;
signalprop.isnoise = true;
}
+
static void printSignal(void) {
prnt("LF signal properties:");
prnt(" high..........%d", signalprop.high);
@@ -83,94 +83,47 @@ static void printSignal(void) {
prnt(" mean..........%d", signalprop.mean);
prnt(" amplitude.....%d", signalprop.amplitude);
prnt(" is Noise......%s", (signalprop.isnoise) ? "Yes" : "No");
- prnt(" THRESHOLD noice amplitude......%d" , NOICE_AMPLITUDE_THRESHOLD);
+ prnt(" THRESHOLD noise amplitude......%d" , NOISE_AMPLITUDE_THRESHOLD);
}
-// Function to compute mean for a series
-// rounded to integer..
-uint32_t compute_mean_uint(uint8_t *in, size_t N) {
- uint32_t mean = 0;
- for (size_t i = 0; i < N; i++)
- mean += in[i];
-
- return mean / N;
-}
-// Function to compute mean for a series
-// rounded to integer..
-int32_t compute_mean_int(int *in, size_t N) {
- int32_t mean = 0;
- for (size_t i = 0; i < N; i++)
- mean += in[i];
-
- return mean / (int)N;
-}
-
-void zeromean(uint8_t* data, size_t size) {
-
- // zero mean data
- int i, accum = 0;
- for (i = 10; i < size; ++i)
- accum += data[i] - 128;
- accum /= (int)(size - 10);
-
- for (i = 0; i < size; ++i) {
- if (accum > 0) {
- data[i] = (data[i] >= accum)? data[i] - accum : 0;
- }
- if (accum < 0) {
- data[i] = (255 - data[i] >= -accum)? data[i] - accum : 255;
- }
- }
- // recompute signal characteristics:
- isNoise(data, size);
-}
-
-//test samples are not just noise
-// By measuring mean and look at amplitude of signal from HIGH / LOW, we can detect noise
-bool isNoise_int(int *bits, uint32_t size) {
+void computeSignalProperties(uint8_t *samples, uint32_t size) {
resetSignal();
- if ( bits == NULL || size < 100 ) return true;
-
- int32_t sum = 0;
- for ( size_t i = 0; i < size; i++) {
- if ( bits[i] < signalprop.low ) signalprop.low = bits[i];
- if ( bits[i] > signalprop.high ) signalprop.high = bits[i];
- sum += bits[i];
- }
- // measure amplitude of signal
- signalprop.mean = sum / (int)size;
- signalprop.amplitude = ABS(signalprop.high - signalprop.mean);
- signalprop.isnoise = signalprop.amplitude < NOICE_AMPLITUDE_THRESHOLD;
-
- if (g_debugMode)
- printSignal();
-
- return signalprop.isnoise;
-}
-//test samples are not just noise
-// By measuring mean and look at amplitude of signal from HIGH / LOW,
-// we can detect noise
-bool isNoise(uint8_t *bits, uint32_t size) {
- resetSignal();
- if ( bits == NULL || size < 100 ) return true;
-
uint32_t sum = 0;
for ( uint32_t i = 0; i < size; i++) {
- if ( bits[i] < signalprop.low ) signalprop.low = bits[i];
- if ( bits[i] > signalprop.high ) signalprop.high = bits[i];
- sum += bits[i];
+ if ( samples[i] < signalprop.low ) signalprop.low = samples[i];
+ if ( samples[i] > signalprop.high ) signalprop.high = samples[i];
+ sum += samples[i];
}
// measure amplitude of signal
signalprop.mean = sum / size;
signalprop.amplitude = signalprop.high - signalprop.mean;
- signalprop.isnoise = signalprop.amplitude < NOICE_AMPLITUDE_THRESHOLD;
-
+ // By measuring mean and look at amplitude of signal from HIGH / LOW,
+ // we can detect noise
+ signalprop.isnoise = signalprop.amplitude < NOISE_AMPLITUDE_THRESHOLD;
+
if (g_debugMode)
printSignal();
+}
- return signalprop.isnoise;
+void removeSignalOffset(uint8_t *samples, uint32_t size) {
+ if ( samples == NULL || size < SIGNAL_MIN_SAMPLES ) return;
+
+ int acc_off = 0;
+ for (uint32_t i = SIGNAL_IGNORE_FIRST_SAMPLES; i < size; i++)
+ acc_off += samples[i] - 128;
+ acc_off /= (int)(size - SIGNAL_IGNORE_FIRST_SAMPLES);
+
+ // shift and saturate samples to center the mean
+ for ( uint32_t i = 0; i < size; i++) {
+ if (acc_off > 0) {
+ samples[i] = (samples[i] >= acc_off)? samples[i] - acc_off : 0;
+ }
+ if (acc_off < 0) {
+ samples[i] = (255 - samples[i] >= -acc_off)? samples[i] - acc_off : 255;
+ }
+ }
}
//by marshmellow
@@ -1962,8 +1915,6 @@ int detectAWID(uint8_t *dest, size_t *size, int *waveStartIdx) {
if (signalprop.isnoise) return -2;
- zeromean(dest, *size);
-
// FSK2a demodulator clock 50, invert 1, fcHigh 10, fcLow 8
*size = fskdemod(dest, *size, 50, 1, 10, 8, waveStartIdx); //awid fsk2a
@@ -2029,8 +1980,6 @@ int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32
if (signalprop.isnoise) return -2;
- zeromean(dest, *size);
-
// FSK demodulator fsk2a so invert and fc/10/8
*size = fskdemod(dest, *size, 50, 1, 10, 8, waveStartIdx); //hid fsk2a
@@ -2090,8 +2039,6 @@ int detectIOProx(uint8_t *dest, size_t *size, int *waveStartIdx) {
if (signalprop.isnoise) return -2;
- zeromean(dest, *size);
-
// FSK demodulator RF/64, fsk2a so invert, and fc/10/8
*size = fskdemod(dest, *size, 64, 1, 10, 8, waveStartIdx); //io fsk2a
diff --git a/common/lfdemod.h b/common/lfdemod.h
index 43537b18b..a6542059e 100644
--- a/common/lfdemod.h
+++ b/common/lfdemod.h
@@ -20,6 +20,14 @@
#include <stdbool.h> // for bool
#include "parity.h" // for parity test
#include "util.h" // for ARRAYLEN
+
+//might not be high enough for noisy environments
+#define NOISE_AMPLITUDE_THRESHOLD 10
+//ignore buffer with less than x samples
+#define SIGNAL_MIN_SAMPLES 100
+//ignore first x samples of the buffer
+#define SIGNAL_IGNORE_FIRST_SAMPLES 10
+
//generic
typedef struct {
int low;
@@ -28,14 +36,10 @@ typedef struct {
int amplitude;
bool isnoise;
} signal_t;
-extern signal_t* getSignalProperties(void);
+signal_t* getSignalProperties(void);
-extern uint32_t compute_mean_uint(uint8_t *in, size_t N);
-extern int32_t compute_mean_int(int *in, size_t N);
-bool isNoise_int(int *bits, uint32_t size);
-bool isNoise(uint8_t *bits, uint32_t size);
-extern void zeromean(uint8_t* data, size_t size);
-
+void computeSignalProperties(uint8_t *bits, uint32_t size);
+void removeSignalOffset(uint8_t *samples, uint32_t size);
void getNextLow(uint8_t *samples, size_t size, int low, size_t *i);
void getNextHigh(uint8_t *samples, size_t size, int high, size_t *i);
bool loadWaveCounters(uint8_t *samples, size_t size, int lowToLowWaveLen[], int highToLowWaveLen[], int *waveCnt, int *skip, int *minClk, int *high, int *low);
From 1cba26decfc6997b3501f45acec2f85746a2c80a Mon Sep 17 00:00:00 2001
From: Philippe Teuwen <phil@teuwen.org>
Date: Fri, 8 Mar 2019 20:30:54 +0100
Subject: [PATCH 2/2] remove redundant removeSignalOffset
---
client/cmddata.c | 4 ----
client/cmdlfem4x.c | 2 --
client/cmdlft55xx.c | 5 ++---
3 files changed, 2 insertions(+), 9 deletions(-)
diff --git a/client/cmddata.c b/client/cmddata.c
index 285b4d189..fc34f3e80 100644
--- a/client/cmddata.c
+++ b/client/cmddata.c
@@ -1471,10 +1471,6 @@ int getSamples(int n, bool silent) {
uint8_t bits[GraphTraceLen];
size_t size = getFromGraphBuf(bits);
- // TODO now DC removal is done already on device, right ?
- // removeSignalOffset(bits, size);
- // push it back to graph
- // setGraphBuf(bits, size);
// set signal properties low/high/mean/amplitude and is_noise detection
computeSignalProperties(bits, size);
diff --git a/client/cmdlfem4x.c b/client/cmdlfem4x.c
index e4909ace9..8b9530957 100644
--- a/client/cmdlfem4x.c
+++ b/client/cmdlfem4x.c
@@ -1000,8 +1000,6 @@ bool downloadSamplesEM(){
return false;
}
- // TODO now DC removal is done already on device, right ?
- // removeSignalOffset(got, sizeof(got));
setGraphBuf(got, sizeof(got));
// set signal properties low/high/mean/amplitude and is_noise detection
computeSignalProperties(got, sizeof(got));
diff --git a/client/cmdlft55xx.c b/client/cmdlft55xx.c
index 446e440ce..b9256fc29 100644
--- a/client/cmdlft55xx.c
+++ b/client/cmdlft55xx.c
@@ -1330,10 +1330,9 @@ bool AquireData( uint8_t page, uint8_t block, bool pwdmode, uint32_t password )
PrintAndLogEx(WARNING, "command execution time out");
return false;
}
- // set signal properties low/high/mean/amplitude and is_noise detection
- removeSignalOffset(got, sizeof(got));
- computeSignalProperties(got, sizeof(got));
setGraphBuf(got, sizeof(got));
+ // set signal properties low/high/mean/amplitude and is_noise detection
+ computeSignalProperties(got, sizeof(got));
RepaintGraphWindow();
return !getSignalProperties()->isnoise;
}