mordae/pico-sdr
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Remove filters that did not pay off

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Signed-off-by: Jan Hamal Dvořák <mordae@anilinux.org>
This commit is contained in:
Jan Hamal Dvořák 2024-01-27 11:55:47 +01:00
parent f73e379222
commit 7a5bcadc23
1 changed files with 2 additions and 68 deletions
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70
src/main.c
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@ -41,9 +41,7 @@
#define RSSI_ALPHA 1
#define LPF_SAMPLES 8 /* 8 */
#define HPF_ALPHA 1 /* 1 */
#define IIR_ON 0
#define SPEED 3
#define PRIME_DELTA 1
#define SLEEP_US 16666
@ -343,53 +341,12 @@ inline static __unused int cheap_angle_diff(int angle1, int angle2)
return diff;
}
#if SPEED == 3
inline static unsigned popcount(unsigned v)
inline static __unused unsigned popcount(unsigned v)
{
v = v - ((v >> 1) & 0x55555555);
v = (v & 0x33333333) + ((v >> 2) & 0x33333333);
return (((v + (v >> 4)) & 0x0f0f0f0f) * 0x01010101) >> 24;
}
#endif
#define NPOLE 3
#define NZERO 3
float acoeff[] = { -0.16915568299951372, 0.8087276367484724, -1.3271950516294135, 1 };
float bcoeff[] = { 1, 3, 3, 1 };
float gain = 25.610088152223362;
inline static __unused float applyfilter(float v, float *xv, float *yv)
{
int i;
float out = 0;
for (i = 0; i < NZERO; i++) {
xv[i] = xv[i + 1];
}
xv[NZERO] = v / gain;
for (i = 0; i < NPOLE; i++) {
yv[i] = yv[i + 1];
}
for (i = 0; i <= NZERO; i++) {
out += xv[i] * bcoeff[i];
}
for (i = 0; i < NPOLE; i++) {
out -= yv[i] * acoeff[i];
}
yv[NPOLE] = out;
return out;
}
inline static __unused float angle_diff(float angle1, float angle2)
{
float diff = fmod(angle2 - angle1, 360.0f);
if (diff > 180.0f)
diff -= 360.0f;
else if (diff < -180.0f)
diff += 360.0f;
return diff;
}
static __unused bool is_prime_or_one(int n)
{
@ -435,14 +392,6 @@ static void rf_rx(void)
}
#endif
#if IIR_ON
float xvI[] = { 0, 0, 0, 0 };
float yvI[] = { 0, 0, 0, 0 };
float xvQ[] = { 0, 0, 0, 0 };
float yvQ[] = { 0, 0, 0, 0 };
#endif
#if SPEED == 2
interp0->ctrl[0] = (31 << SIO_INTERP0_CTRL_LANE0_MASK_MSB_LSB) |
(0 << SIO_INTERP0_CTRL_LANE0_MASK_LSB_LSB) |
@ -502,22 +451,12 @@ static void rf_rx(void)
int delta = ~dma_hw->ch[rx_dma].transfer_count - prev_transfers;
int acceptable_deviation = delta_watermark / 16 + 1;
int acceptable_deviation = delta_watermark / 32 + 1;
if (delta < (delta_watermark - acceptable_deviation)) {
#if PRIME_DELTA
while (!is_prime_or_one(--delta_watermark))
;
#else
delta_watermark--;
#endif
} else if (delta > (delta_watermark + acceptable_deviation)) {
#if PRIME_DELTA
while (!is_prime_or_one(++delta_watermark))
;
#else
delta_watermark++;
#endif
}
while (delta < delta_watermark) {
@ -657,11 +596,6 @@ static void rf_rx(void)
Q = lpQavg3 / (LPF_SAMPLES * LPF_SAMPLES * LPF_SAMPLES);
#endif
#if IIR_ON
I = applyfilter(I, xvI, yvI);
Q = applyfilter(Q, xvQ, yvQ);
#endif
if ((Q < 0) ^ (prevQ < 0)) {
stride *= ((I < 0) ^ (Q < 0)) ? 1 : -1;
period = (63 * period + stride) / 64;