altos/cc1111: Add 2400 and 9600 baud telemetry rate support

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

diff --git a/src/cc1111/ao_pins.h b/src/cc1111/ao_pins.h
index 2d524188679a211d3bc1af7e1f0b8327144edccf..83a3c774a3732ad50ee9f957e41b21b51c3e5d4f 100644 (file)
--- a/src/cc1111/ao_pins.h
+++ b/src/cc1111/ao_pins.h
@@ -57,6 +57,7 @@
        #define HAS_IGNITE              1
        #define HAS_MONITOR             0
        #define HAS_TELEMETRY           1
+       #define HAS_RADIO_RATE          0       /* not enough space for this */
 #endif
 
 #if defined(TELEMETRUM_V_1_1)
@@ -98,6 +99,7 @@
        #define HAS_IGNITE              1
        #define HAS_MONITOR             0
        #define HAS_TELEMETRY           1
+       #define HAS_RADIO_RATE          0       /* not enough space for this */
 #endif
 
 #if defined(TELEMETRUM_V_1_2)
@@ -139,6 +141,7 @@
        #define HAS_IGNITE              1
        #define HAS_MONITOR             0
        #define HAS_TELEMETRY           1
+       #define HAS_RADIO_RATE          0       /* not enough space for this */
 #endif
 
 #if defined(TELEDONGLE_V_0_2)

diff --git a/src/cc1111/ao_radio.c b/src/cc1111/ao_radio.c
index fbdf7762633c65a4b382ef23490b1ad77708a945..8f519958ad350013671f0018fa0abae185ea7b6b 100644 (file)
--- a/src/cc1111/ao_radio.c
+++ b/src/cc1111/ao_radio.c
@@ -40,6 +40,42 @@
 #define IF_FREQ_CONTROL        6
 
 /*
+ *  http://www.ntia.doc.gov/files/ntia/publications/84-168.pdf
+ *
+ * Necessary bandwidth for a FSK modulated signal:
+ *
+ *     bw = 2.6d + 0.55b       1.5 < m < 5.5
+ *     bw = 2.1d + 1.9b        5.5 < m < 20
+ *
+ *     b is the modulation rate in bps
+ *     d is the peak deviation (from the center)
+ *
+ *     m = 2d / b
+ *
+ * 20.5 kHz deviation 38.4kbps signal:
+ *
+ *     m = 41 / 38.4, which is < 5.5:
+ *
+ *     bw = 2.6 * 20.5 + 0.55 * 38.4 = 74.42kHz
+ *
+ *     M = 1, E = 3, bw = 75kHz
+ *
+ * 20.5 kHz deviation, 9.6kbps signal
+ *
+ *     m = 41 / 9.6, which is < 5.5:
+ *
+ *     bw = 2.6 * 20.5 + 0.55 * 9.6 = 58.58kHz
+ *
+ *     M = 2, E = 3, bw = 62.5kHz
+ *
+ * 20.5kHz deviation, 2.4kbps signal
+ *
+ *     m = 41 / 2.4, which is > 5.5:
+ *
+ *     bw = 2.1 * 20.5 + 1.9 * 2.4 = 47.61kHz
+ *
+ *     M = 3, E = 3, bw = 53.6kHz
+ *
  * For channel bandwidth of 93.75 kHz, the CHANBW_E and CHANBW_M values are
  *
  * BW = 24e6 / (8 * (4 + M) * 2 ** E)
@@ -47,7 +83,9 @@
  * So, M = 0 and E = 3
  */
 
-#define CHANBW_M       0
+#define CHANBW_M_384   1
+#define CHANBW_M_96    2
+#define CHANBW_M_24    3
 #define CHANBW_E       3
 
 /*
@@ -55,12 +93,23 @@
  *
  * R = (256 + M) * 2** E * 24e6 / 2**28
  *
- * So M is 163 and E is 10
+ * So for 38360kBaud, M is 163 and E is 10
  */
 
-#define DRATE_E                10
 #define DRATE_M                163
 
+#define DRATE_E_384    10
+
+/* For 9600 baud, M is 163 and E is 8
+ */
+
+#define DRATE_E_96     8
+
+/* For 2400 baud, M is 163 and E is 6
+ */
+
+#define DRATE_E_24     6
+
 /*
  * For a channel deviation of 20.5kHz, the DEVIATION_E and DEVIATION_M values are:
  *
@@ -122,9 +171,6 @@ static __code uint8_t radio_setup[] = {
        RF_FSCTRL1_OFF,         (IF_FREQ_CONTROL << RF_FSCTRL1_FREQ_IF_SHIFT),
        RF_FSCTRL0_OFF,         (0 << RF_FSCTRL0_FREQOFF_SHIFT),
 
-       RF_MDMCFG4_OFF,         ((CHANBW_E << RF_MDMCFG4_CHANBW_E_SHIFT) |
-                                (CHANBW_M << RF_MDMCFG4_CHANBW_M_SHIFT) |
-                                (DRATE_E << RF_MDMCFG4_DRATE_E_SHIFT)),
        RF_MDMCFG3_OFF,         (DRATE_M << RF_MDMCFG3_DRATE_M_SHIFT),
        RF_MDMCFG2_OFF,         (RF_MDMCFG2_DEM_DCFILT_ON |
                                 RF_MDMCFG2_MOD_FORMAT_GFSK |
@@ -204,7 +250,7 @@ static __code uint8_t radio_setup[] = {
 
 static __code uint8_t rdf_setup[] = {
        RF_MDMCFG4_OFF,         ((CHANBW_E << RF_MDMCFG4_CHANBW_E_SHIFT) |
-                                (CHANBW_M << RF_MDMCFG4_CHANBW_M_SHIFT) |
+                                (CHANBW_M_384 << RF_MDMCFG4_CHANBW_M_SHIFT) |
                                 (RDF_DRATE_E << RF_MDMCFG4_DRATE_E_SHIFT)),
        RF_MDMCFG3_OFF,         (RDF_DRATE_M << RF_MDMCFG3_DRATE_M_SHIFT),
        RF_MDMCFG2_OFF,         (RF_MDMCFG2_DEM_DCFILT_OFF |
@@ -225,9 +271,11 @@ static __code uint8_t rdf_setup[] = {
 };
 
 static __code uint8_t fixed_pkt_setup[] = {
+#if !HAS_RADIO_RATE
        RF_MDMCFG4_OFF,         ((CHANBW_E << RF_MDMCFG4_CHANBW_E_SHIFT) |
-                                (CHANBW_M << RF_MDMCFG4_CHANBW_M_SHIFT) |
-                                (DRATE_E << RF_MDMCFG4_DRATE_E_SHIFT)),
+                                (CHANBW_M_384 << RF_MDMCFG4_CHANBW_M_SHIFT) |
+                                (DRATE_E_384 << RF_MDMCFG4_DRATE_E_SHIFT)),
+#endif
        RF_MDMCFG3_OFF,         (DRATE_M << RF_MDMCFG3_DRATE_M_SHIFT),
        RF_MDMCFG2_OFF,         (RF_MDMCFG2_DEM_DCFILT_ON |
                                 RF_MDMCFG2_MOD_FORMAT_GFSK |
@@ -249,6 +297,23 @@ static __code uint8_t fixed_pkt_setup[] = {
                                 RF_PKTCTRL0_LENGTH_CONFIG_FIXED),
 };
 
+#if HAS_RADIO_RATE
+static __code uint8_t packet_rate_setup[] = {
+       /* 38400 */
+       ((CHANBW_E << RF_MDMCFG4_CHANBW_E_SHIFT) |
+        (CHANBW_M_384 << RF_MDMCFG4_CHANBW_M_SHIFT) |
+        (DRATE_E_384 << RF_MDMCFG4_DRATE_E_SHIFT)),
+       /* 9600 */
+       ((CHANBW_E << RF_MDMCFG4_CHANBW_E_SHIFT) |
+        (CHANBW_M_96 << RF_MDMCFG4_CHANBW_M_SHIFT) |
+        (DRATE_E_96 << RF_MDMCFG4_DRATE_E_SHIFT)),
+       /* 2400 */
+       ((CHANBW_E << RF_MDMCFG4_CHANBW_E_SHIFT) |
+        (CHANBW_M_24 << RF_MDMCFG4_CHANBW_M_SHIFT) |
+        (DRATE_E_24 << RF_MDMCFG4_DRATE_E_SHIFT)),
+};
+#endif
+
 __xdata uint8_t        ao_radio_dma;
 __xdata uint8_t ao_radio_dma_done;
 __xdata uint8_t ao_radio_done;
@@ -314,6 +379,9 @@ ao_radio_get(uint8_t len)
        RF_FREQ1 = (uint8_t) (ao_config.radio_setting >> 8);
        RF_FREQ0 = (uint8_t) (ao_config.radio_setting);
        RF_PKTLEN = len;
+#if HAS_RADIO_RATE
+       RF_MDMCFG4 = packet_rate_setup[ao_config.radio_rate];
+#endif
 }