Add some documentation.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@3062 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/bertos/net/afsk.c b/bertos/net/afsk.c
index 4164fccd769272a2c6c1b5d8773eb04416d9726e..c30cb22502457899fad5cb5c17cd80bda783ac94 100644 (file)
--- a/bertos/net/afsk.c
+++ b/bertos/net/afsk.c
@@ -254,7 +254,9 @@ void afsk_adc_isr(Afsk *af, int8_t curr_sample)
                 * Determine bit value by reading the last 3 sampled bits.
                 * If the number of ones is two or greater, the bit value is a 1,
                 * otherwise is a 0.
+                * This algorithm presumes that there are 8 samples per bit.
                 */
+               STATIC_ASSERT(SAMPLEPERBIT == 8);
                uint8_t bits = af->sampled_bits & 0x07;
                if (bits == 0x07 // 111, 3 bits set to 1
                 || bits == 0x06 // 110, 2 bits

diff --git a/bertos/net/afsk.h b/bertos/net/afsk.h
index 902c5b9470944a6fbd136ab248ba7acfc7e608e9..4a040fd9f4efb68e6cf6b3e951f936abcd848b6e 100644 (file)
--- a/bertos/net/afsk.h
+++ b/bertos/net/afsk.h
@@ -52,8 +52,19 @@
 #include <struct/fifobuf.h>
 
 
-// Demodulator constants
+
+/**
+ * ADC sample rate.
+ * The demodulator filters are designed to work at this frequency.
+ * If you need to change this remember to update afsk_adc_isr().
+ */
 #define SAMPLERATE 9600
+
+/**
+ * Bitrate of the received/transmitted data.
+ * The demodulator filters and decoderes are designed to work at this frequency.
+ * If you need to change this remember to update afsk_adc_isr().
+ */
 #define BITRATE    1200
 
 #define SAMPLEPERBIT (SAMPLERATE / BITRATE)
@@ -182,8 +193,33 @@ INLINE Afsk *AFSK_CAST(KFile *fd)
   return (Afsk *)fd;
 }
 
-void afsk_adc_isr(Afsk *af, int8_t curr_sample);
+/**
+ * ADC ISR callback.
+ * This function has to be called by the ADC ISR when a sample of the configured
+ * channel is available.
+ * \param af Afsk context to operate one (\see Afsk).
+ * \param sample current sample from the ADC.
+ */
+void afsk_adc_isr(Afsk *af, int8_t sample);
+
+/**
+ * DAC ISR callback.
+ * This function has to be called by the DAC ISR when a sample of the configured
+ * channel has been converted out.
+ *
+ * \param af Afsk context to operate one (\see Afsk).
+ *
+ * \note The next DAC output sample is supplied by the Afsk driver through calling
+ *        the AFSK_DAC_SET() callback.
+ */
 void afsk_dac_isr(Afsk *af);
+
+/**
+ * Initialize an AFSK1200 modem.
+ * \param af Afsk context to operate one (\see Afsk).
+ * \param adc_ch  ADC channel used by the demodulator.
+ * \param dac_ch  DAC channel used by the modulator.
+ */
 void afsk_init(Afsk *af, int adc_ch, int dac_ch);