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Before Hamming code

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Mark Qvist 2014-04-13 15:42:48 +02:00
parent dbe32bd02e
commit 3644a35b79
3 changed files with 18 additions and 19 deletions
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34
Modem/afsk.c
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@ -93,7 +93,7 @@ INLINE uint8_t sinSample(uint16_t i) {
#define PHASE_BITS 8 // How much to increment phase counter each sample #define PHASE_BITS 8 // How much to increment phase counter each sample
#define PHASE_INC 1 // Nudge by an eigth of a sample each adjustment #define PHASE_INC 1 // Nudge by an eigth of a sample each adjustment
#define PHASE_MAX (SAMPLESPERBIT * PHASE_BITS) // Resolution of our phase counter = 64 #define PHASE_MAX (SAMPLESPERBIT * PHASE_BITS) // Resolution of our phase counter = 64
#define PHASE_THRESHOLD (PHASE_MAX / 4) // Target transition point of our phase window #define PHASE_THRESHOLD (PHASE_MAX / 2) // Target transition point of our phase window
// Modulation constants // Modulation constants
#define MARK_FREQ 1200 // The tone frequency signifying a binary one #define MARK_FREQ 1200 // The tone frequency signifying a binary one
@ -373,24 +373,24 @@ void afsk_adc_isr(Afsk *afsk, int8_t currentSample) {
// more 1's, we will assume that the transmitter // more 1's, we will assume that the transmitter
// sent us a one, otherwise we assume a zero // sent us a one, otherwise we assume a zero
uint8_t bits = afsk->sampledBits & 0x0f; // uint8_t bits = afsk->sampledBits & 0x0f;
uint8_t c = 0; // uint8_t c = 0;
c += bits & BV(1); // c += bits & BV(1);
c += bits & BV(2); // c += bits & BV(2);
c += bits & BV(3); // c += bits & BV(3);
c += bits & BV(4); // c += bits & BV(4);
c += bits & BV(5); // c += bits & BV(5);
if (c >= 3) afsk->actualBits |= 1; // if (c >= 3) afsk->actualBits |= 1;
//// Alternative using only three bits ////////// //// Alternative using only three bits //////////
// uint8_t bits = afsk->sampledBits & 0x07; uint8_t bits = afsk->sampledBits & 0x07;
// if (bits == 0x07 || // 111 if (bits == 0x07 || // 111
// bits == 0x06 || // 110 bits == 0x06 || // 110
// bits == 0x05 || // 101 bits == 0x05 || // 101
// bits == 0x03 // 011 bits == 0x03 // 011
// ) { ) {
// afsk->actualBits |= 1; afsk->actualBits |= 1;
// } }
///////////////////////////////////////////////// /////////////////////////////////////////////////
// Now we can pass the actual bit to the HDLC parser. // Now we can pass the actual bit to the HDLC parser.

1
Modem/hardware.c
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@ -67,7 +67,6 @@ void hw_afsk_adcInit(int ch, Afsk *_modem)
// temperature variations, but if you have a board with a // temperature variations, but if you have a board with a
// crystal that is way off frequency, this can help alot. // crystal that is way off frequency, this can help alot.
ICR1 = (((CPU_FREQ+FREQUENCY_CORRECTION)) / 9600) - 1; ICR1 = (((CPU_FREQ+FREQUENCY_CORRECTION)) / 9600) - 1;
kprintf("ICR1=%d",ICR1);
// Set reference to AVCC (5V), select pin // Set reference to AVCC (5V), select pin
// Set the ADMUX register. The first part (BV(REFS0)) sets // Set the ADMUX register. The first part (BV(REFS0)) sets

2
buildrev.h
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@ -1,2 +1,2 @@
#define VERS_BUILD 549 #define VERS_BUILD 577
#define VERS_HOST "vixen" #define VERS_HOST "vixen"