Fox's Git Mirrors
Commit 56bed681438f684cef11166a6e08bf43c21c0ab8
Parents : 74e0b0d
Author : Mark Qvist <mark@adepta.io>
Date : 2018-12-30T00:32:19+01:00
Filters reworked for new samplerate
Changes
4 files changed, 69 insertions(+), 57 deletions(-)
Diff
diff --git a/device.h b/device.h
index de17112..af5e707 100755
--- a/device.h
+++ b/device.h
@@ -14,8 +14,6 @@
// Sampling & timer setup
#define CONFIG_SAMPLERATE 19200UL
-//#define CONFIG_SAMPLERATE 19200UL
-//#define CONFIG_SAMPLERATE 9600
// Serial settings
#define BAUD 115200
@@ -25,6 +23,9 @@
// CSMA Settings
#define CONFIG_CSMA_P 255
+// Packet settings
+#define CONFIG_PASSALL false
+
// Port settings
#if TARGET_CPU == m1284p
#define ADC_PORT PORTA
diff --git a/hardware/AFSK.c b/hardware/AFSK.c
index f0d8a44..dee9c83 100755
--- a/hardware/AFSK.c
+++ b/hardware/AFSK.c
@@ -375,54 +375,53 @@ void AFSK_adc_isr(Afsk *afsk, int8_t currentSample) {
afsk->iirX[0] = afsk->iirX[1];
- #if FILTER_CUTOFF == 600
- afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) >> 2;
- // The above is a simplification of:
- // afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / 3.558147322;
- #elif FILTER_CUTOFF == 800
- afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) >> 2;
- // The above is a simplification of:
- // afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / 2.899043379;
- #elif FILTER_CUTOFF == 1200
- afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) >> 1;
- // The above is a simplification of:
- // afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / 2.228465666;
- #elif FILTER_CUTOFF == 1600
- afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) >> 1;
- // The above is a simplification of:
- // afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / 1.881349100;
+ #if CONFIG_SAMPLERATE == 9600
+ #if FILTER_CUTOFF == 600
+ afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) >> 2;
+ // The above is a simplification of:
+ // afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / 3.558147322;
+ #else
+ #error Unsupported filter cutoff!
+ #endif
+ #elif CONFIG_SAMPLERATE == 19200
+ #if FILTER_CUTOFF == 600
+ afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / 6;
+ #else
+ #error Unsupported filter cutoff!
+ #endif
#else
- #error Unsupported filter cutoff!
+ #error Unsupported samplerate!
#endif
afsk->iirY[0] = afsk->iirY[1];
- #if FILTER_CUTOFF == 600
- afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] >> 1);
- // The above is a simplification of a first-order 600Hz chebyshev filter:
- // afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] * 0.4379097269);
- #elif FILTER_CUTOFF == 800
- afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / 3);
- // The above is a simplification of a first-order 800Hz chebyshev filter:
- // afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] * 0.3101172565);
- #elif FILTER_CUTOFF == 1200
- afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / 10);
- // The above is a simplification of a first-order 1200Hz chebyshev filter:
- // afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] * 0.1025215106);
- #elif FILTER_CUTOFF == 1600
- afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + -1*(afsk->iirY[0] / 17);
- // The above is a simplification of a first-order 1600Hz chebyshev filter:
- // afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] * -0.0630669239);
+ #if CONFIG_SAMPLERATE == 9600
+ #if FILTER_CUTOFF == 600
+ afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] >> 1);
+ // The above is a simplification of:
+ // afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] * 0.4379097269);
+ #else
+ #error Unsupported filter cutoff!
+ #endif
+ #elif CONFIG_SAMPLERATE == 19200
+ #if FILTER_CUTOFF == 600
+ afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / 2);
+ #else
+ #error Unsupported filter cutoff!
+ #endif
#else
- #error Unsupported filter cutoff!
+ #error Unsupported samplerate!
#endif
-
+
+ //int8_t freq_disc = (int8_t)fifo_pop(&afsk->delayFifo) * currentSample;
// We put the sampled bit in a delay-line:
// First we bitshift everything 1 left
afsk->sampledBits <<= 1;
+
// And then add the sampled bit to our delay line
afsk->sampledBits |= (afsk->iirY[1] > 0) ? 0 : 1;
+ //afsk->sampledBits |= (freq_disc > 0) ? 0 : 1;
// Put the current raw sample in the delay FIFO
fifo_push(&afsk->delayFifo, currentSample);
@@ -489,6 +488,7 @@ void AFSK_adc_isr(Afsk *afsk, int8_t currentSample) {
// the last 3 sampled bits. If there is two or
// more 1's, we will assume that the transmitter
// sent us a one, otherwise we assume a zero
+
uint8_t bits = afsk->sampledBits & 0x07;
if (bits == 0x07 || // 111
bits == 0x06 || // 110
@@ -498,15 +498,17 @@ void AFSK_adc_isr(Afsk *afsk, int8_t currentSample) {
afsk->actualBits |= 1;
}
- //// Alternative using five bits ////////////////
- // uint8_t bits = afsk->sampledBits & 0x0f;
- // uint8_t c = 0;
- // c += bits & BV(1);
- // c += bits & BV(2);
- // c += bits & BV(3);
- // c += bits & BV(4);
- // c += bits & BV(5);
- // if (c >= 3) afsk->actualBits |= 1;
+
+ //// Alternative using six bits ////////////////
+ // uint8_t bits = afsk->sampledBits & 0x3F;
+ // uint8_t c = 0;
+ // c += bits & _BV(0);
+ // c += bits & _BV(1);
+ // c += bits & _BV(2);
+ // c += bits & _BV(3);
+ // c += bits & _BV(4);
+ // c += bits & _BV(5);
+ // if (c >= 3) afsk->actualBits |= 1;
/////////////////////////////////////////////////
// Now we can pass the actual bit to the HDLC parser.
diff --git a/hardware/AFSK.h b/hardware/AFSK.h
index 59a7349..b6698f5 100755
--- a/hardware/AFSK.h
+++ b/hardware/AFSK.h
@@ -35,9 +35,11 @@ inline static uint8_t sinSample(uint16_t i) {
#define BITS_DIFFER(bits1, bits2) (((bits1)^(bits2)) & 0x01)
#define TRANSITION_FOUND(bits) BITS_DIFFER((bits), (bits) >> 1)
-// TODO: Maybe expand number of bits looked at here:
+// TODO: Maybe revert to only looking at two samples
#define DUAL_XOR(bits1, bits2) ((((bits1)^(bits2)) & 0x03) == 0x03)
-#define SIGNAL_TRANSITIONED(bits) DUAL_XOR((bits), (bits) >> 2)
+#define QUAD_XOR(bits1, bits2) ((((bits1)^(bits2)) & 0x0F) == 0x0F)
+#define SIGNAL_TRANSITIONED(bits) QUAD_XOR((bits), (bits) >> 4)
+// #define SIGNAL_TRANSITIONED(bits) DUAL_XOR((bits), (bits) >> 2)
#define CPU_FREQ F_CPU
@@ -53,16 +55,19 @@ inline static uint8_t sinSample(uint16_t i) {
#define SAMPLESPERBIT (CONFIG_SAMPLERATE / BITRATE)
#define TICKS_BETWEEN_SAMPLES ((((CPU_FREQ+FREQUENCY_CORRECTION)) / CONFIG_SAMPLERATE) - 1)
-// TODO: Calculate based on sample rate
-#define PHASE_INC SAMPLESPERBIT/8 // Nudge by an eigth of a sample each adjustment
-#define PHASE_BITS 8 // How much to increment phase counter each sample
+// TODO: Calculate based on sample rate [Done?]
+#define PHASE_BITS 8 // 8 // Sub-sample phase counter resolution
+#define PHASE_INC 1 // 1 // Nudge by above resolution for each adjustment
-#define PHASE_MAX (SAMPLESPERBIT * PHASE_BITS) // Resolution of our phase counter
-#define PHASE_THRESHOLD (PHASE_MAX / 2) // Target transition point of our phase window
+#define PHASE_MAX (SAMPLESPERBIT * PHASE_BITS) // 128 // Size of our phase counter
+// TODO: Test which target is best in real world
+#define PHASE_THRESHOLD (PHASE_MAX / 2)+3*PHASE_BITS // Target transition point of our phase window
+//#define PHASE_THRESHOLD (PHASE_MAX / 2) // 64 // Target transition point of our phase window
#define DCD_TIMEOUT_SAMPLES CONFIG_SAMPLERATE/100
#define DCD_MIN_COUNT CONFIG_SAMPLERATE/1600
-
+
+// TODO: Revamp filtering
#if BITRATE == 1200
#define FILTER_CUTOFF 600
#define MARK_FREQ 1200
@@ -120,8 +125,12 @@ typedef struct Afsk
int16_t iirX[2]; // IIR Filter X cells
int16_t iirY[2]; // IIR Filter Y cells
- uint8_t sampledBits; // Bits sampled by the demodulator (at ADC speed)
- int8_t currentPhase; // Current phase of the demodulator
+ #if SAMPLESPERBIT < 17
+ uint16_t sampledBits; // Bits sampled by the demodulator (at ADC speed)
+ #else
+ #error Not enough space in sampledBits variable!
+ #endif
+ int16_t currentPhase; // Current phase of the demodulator
uint8_t actualBits; // Actual found bits at correct bitrate
volatile int status; // Status of the modem, 0 means OK
diff --git a/protocol/AX25.c b/protocol/AX25.c
index 62015cd..001b418 100755
--- a/protocol/AX25.c
+++ b/protocol/AX25.c
@@ -31,7 +31,7 @@ void ax25_poll(AX25Ctx *ctx) {
while ((c = fgetc(ctx->ch)) != EOF) {
if (!ctx->escape && c == HDLC_FLAG) {
if (ctx->frame_len >= AX25_MIN_FRAME_LEN) {
- if (ctx->crc_in == AX25_CRC_CORRECT) {
+ if (ctx->crc_in == AX25_CRC_CORRECT || CONFIG_PASSALL) {
#if OPEN_SQUELCH == true
LED_RX_ON();
#endif
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