altos: Start restructuring APRS code to create and send packets

Signed-off-by: Keith Packard <keithp@keithp.com>

2 files changed, 72 insertions, 32 deletions

diff --git a/src/drivers/ao_aprs.c b/src/drivers/ao_aprs.c
index 7e9013a0..b8d17bd9 100644
--- a/src/drivers/ao_aprs.c
+++ b/src/drivers/ao_aprs.c
@@ -238,22 +238,6 @@ void timeInit()
     timeNCOFreq = 0x2000;
 }
 
-/**
- *   Timer interrupt handler called every 104uS (9600 times/second).
- */
-void timeUpdate()
-{
-    putchar ((timeNCO >> 8) < 0x80 ? 0xc0 : 0x40);
-
-    timeNCO += timeNCOFreq;
-
-    if (++timeLowRateCount == 8) 
-    {
-	timeLowRateCount = 0;
-	tnc1200TimerTick();
-    } // END if
-}
-
 /** @} */
 
 /**
@@ -553,6 +537,28 @@ void tncPositionPacket(void)
     tncLength += c;
 }
 
+static int16_t
+tncFill(uint8_t *buf, int16_t len)
+{
+    int16_t	l = 0;
+    uint8_t	b;
+    uint8_t	bit;
+
+    while (tncMode != TNC_TX_READY && l < len) {
+	b = 0;
+	for (bit = 0; bit < 8; bit++) {
+	    b = b << 1 | (timeNCO >> 15);
+	    timeNCO += timeNCOFreq;
+	}
+	*buf++ = b;
+	l++;
+	tnc1200TimerTick();
+    }
+    if (tncMode == TNC_TX_READY)
+	l = -l;
+    return l;
+}
+
 /** 
  *    Prepare an AX.25 data packet.  Each time this method is called, it automatically
  *    rotates through 1 of 3 messages.
@@ -589,19 +595,9 @@ void tncTxPacket(void)
     tncIndex = 0;
     tncMode = TNC_TX_SYNC;
 
-    // Turn on the PA chain.
-//    output_high (IO_PTT);
-
-    // Wait for the PA chain to power up.
-//    delay_ms (10);
-
-    // Key the DDS.
-//    output_high (IO_OSK);
+    timeInit();
 
-    // Log the battery and reference voltage just after we key the transmitter.
-//    sysLogVoltage();
-    while (tncMode != TNC_TX_READY)
-	timeUpdate();
+    ao_radio_send_lots(tncFill);
 }
 
 /** @} */
diff --git a/src/test/ao_aprs_test.c b/src/test/ao_aprs_test.c
index 93dab577..d350ca0d 100644
--- a/src/test/ao_aprs_test.c
+++ b/src/test/ao_aprs_test.c
@@ -25,6 +25,27 @@
 
 #define AO_APRS_TEST
 
+typedef int16_t (*ao_radio_fill_func)(uint8_t *buffer, int16_t len);
+
+#define DEBUG 0
+#if DEBUG
+void
+ao_aprs_bit(uint8_t bit)
+{
+	static int	seq = 0;
+	printf ("%6d %d\n", seq++, bit ? 1 : 0);
+}
+#else
+void
+ao_aprs_bit(uint8_t bit)
+{
+	putchar (bit ? 0xc0 : 0x40);
+}
+#endif
+
+void
+ao_radio_send_lots(ao_radio_fill_func fill);
+
 #include <ao_aprs.c>
 
 /*
@@ -57,10 +78,12 @@
 static void
 audio_gap(int secs)
 {
+#if !DEBUG
 	int	samples = secs * 9600;
 
 	while (samples--)
-		putchar(0x7f);
+		ao_aprs_bit(0);
+#endif
 }
 
 // This is where we go after reset.
@@ -76,6 +99,27 @@ int main(int argc, char **argv)
     exit(0);
 }
 
-
-
-
+void
+ao_radio_send_lots(ao_radio_fill_func fill)
+{
+	int16_t	len;
+	uint8_t	done = 0;
+	uint8_t	buf[16], *b, c;
+	uint8_t bit;
+
+	while (!done) {
+		len = (*fill)(buf, sizeof (buf));
+		if (len < 0) {
+			done = 1;
+			len = -len;
+		}
+		b = buf;
+		while (len--) {
+			c = *b++;
+			for (bit = 0; bit < 8; bit++) {
+				ao_aprs_bit(c & 0x80);
+				c <<= 1;
+			}
+		}
+	}
+}