From 6b496c35ebe0a1f5eb27b2a4b9c1bc4a61391877 Mon Sep 17 00:00:00 2001
From: Mark Qvist <markq@qvistconsult.com>
Date: Fri, 4 Apr 2014 08:58:18 +0200
Subject: [PATCH] Cleanup

---
 Modem/afsk.c |  7 ++-----
 Modem/afsk.h | 10 +++-------
 buildrev.h   |  2 +-
 3 files changed, 6 insertions(+), 13 deletions(-)

diff --git a/Modem/afsk.c b/Modem/afsk.c
index c4ad488..307328d 100644
--- a/Modem/afsk.c
+++ b/Modem/afsk.c
@@ -5,12 +5,9 @@
 #include <drv/timer.h>
 #include <cfg/module.h>
 
-#include <cfg/log.h>
-
 #include <cpu/power.h>
 #include <cpu/pgm.h>
 #include <struct/fifobuf.h>
-
 #include <string.h>
 
 // Sine table for DAC DDS
@@ -28,7 +25,7 @@ static const uint8_t PROGMEM sin_table[] =
 }; STATIC_ASSERT(sizeof(sin_table) == SIN_LEN / 4);
 
 
-// Calculate Sine value from quarter sine table
+// Calculate any sine value from quarter wave sine table
 INLINE uint8_t sinSample(uint16_t i) {
 	ASSERT(i < SIN_LEN);
 	uint16_t newI = i % (SIN_LEN/2);
@@ -147,7 +144,7 @@ void afsk_adc_isr(Afsk *afsk, int8_t currentSample) {
 	// the bit of the sample, we multiply the sample by
 	// a sample delayed by (samples per bit / 2).
 	// We then lowpass-filter the sample with a first
-	// order 600Hz filter
+	// order 600Hz filter. This is a Chebyshev filter.
 
 	afsk->iirX[0] = afsk->iirX[1];
 	afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) >> 2;
diff --git a/Modem/afsk.h b/Modem/afsk.h
index 9801d51..406711e 100644
--- a/Modem/afsk.h
+++ b/Modem/afsk.h
@@ -10,9 +10,9 @@
 #include <struct/fifobuf.h>
 
 
-#define SAMPLERATE 9600
-#define BITRATE    1200
-#define SAMPLESPERBIT (SAMPLERATE / BITRATE)
+#define SAMPLERATE 9600			// The rate at which we are sampling and synthesizing
+#define BITRATE    1200			// The actual bitrate at baseband. This is the baudrate.
+#define SAMPLESPERBIT (SAMPLERATE / BITRATE)	// How many DAC/ADC samples constitute on bit (8).
 
 typedef struct Hdlc
 {
@@ -99,8 +99,4 @@ void afsk_adc_isr(Afsk *af, int8_t sample);
 uint8_t afsk_dac_isr(Afsk *af);
 void afsk_init(Afsk *af, int adc_ch, int dac_ch);
 
-//int afsk_testSetup(void);
-//int afsk_testRun(void);
-//int afsk_testTearDown(void);
-
 #endif
diff --git a/buildrev.h b/buildrev.h
index ef3342b..df4ea1b 100644
--- a/buildrev.h
+++ b/buildrev.h
@@ -1,2 +1,2 @@
-#define VERS_BUILD 123
+#define VERS_BUILD 126
 #define VERS_HOST  "vixen"