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FIX: detect noise signal by measuring amplitude of signal.

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iceman1001 2017-10-30 19:18:30 +01:00
commit db56ca11a3
4 changed files with 44 additions and 23 deletions
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25
client/graph.c
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@ -265,16 +265,29 @@ uint8_t fskClocks(uint8_t *fc1, uint8_t *fc2, uint8_t *rf1, bool verbose, int *f
return 1;
}
// test samples are not just noise
//test samples are not just noise
// By measuring mean and look at amplitude of signal from HIGH / LOW,
// we can detect noise
bool is_justnoise(int *bits, uint32_t size) {
//might not be high enough for noisy environments
#define NOICE_THRESHOLD 15;
#define NOICE_AMPLITUDE_THRESHOLD 10;
// if we take the mean on the sample set and see if its
// below the threshold, it will be a better indicator
int32_t mean = compute_mean_int(bits, size);
return mean < NOICE_THRESHOLD;
uint32_t sum = 0, mean = 0, high = 0, low = 255;
for ( size_t i = 0; i < size; i++) {
if ( bits[i] < low ) low = bits[i];
if ( bits[i] > high ) high = bits[i];
sum += bits[i];
}
mean = sum / size;
// measure amplitude of signal
bool isnoise = (high - mean) < NOICE_AMPLITUDE_THRESHOLD;
if (g_debugMode == 2)
PrintAndLog("DEBUG: (is_justnoise) mean %u | hi %u | low %u | IS NOISE %c", mean, high, low, isnoise?'Y':'N');
return isnoise;
/*
bool isNoise = true;
for(int i=0; i < size && isNoise; i++)