From 684f53d67379cf2ae696fab93d81e49208dfa43c Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Wed, 5 Dec 2012 21:34:05 -0800 Subject: [PATCH] altos: Remove APRS sine-wave table We're generating a lovely square wave, which appears to be decoded just fine thankyouverymuch. Signed-off-by: Keith Packard --- src/drivers/ao_aprs.c | 99 +------------------------------------------ 1 file changed, 1 insertion(+), 98 deletions(-) diff --git a/src/drivers/ao_aprs.c b/src/drivers/ao_aprs.c index 86f5f650..937be734 100644 --- a/src/drivers/ao_aprs.c +++ b/src/drivers/ao_aprs.c @@ -173,82 +173,6 @@ void tncTxPacket(void); /** @} */ -/** - * @defgroup DDS AD9954 DDS (Direct Digital Synthesizer) - * - * Functions to control the Analog Devices AD9954 DDS. - * - * @{ - */ - -/// Number of digits in DDS frequency to FTW conversion. -#define DDS_FREQ_TO_FTW_DIGITS 9 - -/// Array of multiplication factors used to convert frequency to the FTW. -const uint32_t DDS_MULT[DDS_FREQ_TO_FTW_DIGITS] = { 11, 7, 7, 3, 4, 8, 4, 9, 1 }; - -/// Array of divisors used to convert frequency to the FTW. -const uint32_t DDS_DIVISOR[DDS_FREQ_TO_FTW_DIGITS - 1] = { 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000 }; - -/// Lookup table to convert dB amplitude scale in 0.5 steps to a linear DDS scale factor. -const uint16_t DDS_AMP_TO_SCALE[] = -{ - 16383, 15467, 14601, 13785, 13013, 12286, 11598, 10949, 10337, 9759, 9213, 8697, - 8211, 7752, 7318, 6909, 6522, 6157, 5813, 5488, 5181, 4891, 4617, 4359, 4115, 3885, 3668, 3463, - 3269, 3086, 2913, 2750, 2597, 2451, 2314, 2185, 2062, 1947, 1838, 1735, 1638 -}; - - -/// Frequency Word List - 4.0KHz FM frequency deviation at 81.15MHz (445.950MHz) -const uint32_t freqTable[256] = -{ - 955418300, 955419456, 955420611, 955421765, 955422916, 955424065, 955425210, 955426351, - 955427488, 955428618, 955429743, 955430861, 955431971, 955433073, 955434166, 955435249, - 955436322, 955437385, 955438435, 955439474, 955440500, 955441513, 955442511, 955443495, - 955444464, 955445417, 955446354, 955447274, 955448176, 955449061, 955449926, 955450773, - 955451601, 955452408, 955453194, 955453960, 955454704, 955455426, 955456126, 955456803, - 955457457, 955458088, 955458694, 955459276, 955459833, 955460366, 955460873, 955461354, - 955461809, 955462238, 955462641, 955463017, 955463366, 955463688, 955463983, 955464250, - 955464489, 955464701, 955464884, 955465040, 955465167, 955465266, 955465337, 955465380, - 955465394, 955465380, 955465337, 955465266, 955465167, 955465040, 955464884, 955464701, - 955464489, 955464250, 955463983, 955463688, 955463366, 955463017, 955462641, 955462238, - 955461809, 955461354, 955460873, 955460366, 955459833, 955459276, 955458694, 955458088, - 955457457, 955456803, 955456126, 955455426, 955454704, 955453960, 955453194, 955452408, - 955451601, 955450773, 955449926, 955449061, 955448176, 955447274, 955446354, 955445417, - 955444464, 955443495, 955442511, 955441513, 955440500, 955439474, 955438435, 955437385, - 955436322, 955435249, 955434166, 955433073, 955431971, 955430861, 955429743, 955428618, - 955427488, 955426351, 955425210, 955424065, 955422916, 955421765, 955420611, 955419456, - 955418300, 955417144, 955415989, 955414836, 955413684, 955412535, 955411390, 955410249, - 955409113, 955407982, 955406857, 955405740, 955404629, 955403528, 955402435, 955401351, - 955400278, 955399216, 955398165, 955397126, 955396100, 955395088, 955394089, 955393105, - 955392136, 955391183, 955390246, 955389326, 955388424, 955387540, 955386674, 955385827, - 955385000, 955384192, 955383406, 955382640, 955381896, 955381174, 955380474, 955379797, - 955379143, 955378513, 955377906, 955377324, 955376767, 955376235, 955375728, 955375246, - 955374791, 955374362, 955373959, 955373583, 955373234, 955372912, 955372618, 955372350, - 955372111, 955371900, 955371716, 955371560, 955371433, 955371334, 955371263, 955371220, - 955371206, 955371220, 955371263, 955371334, 955371433, 955371560, 955371716, 955371900, - 955372111, 955372350, 955372618, 955372912, 955373234, 955373583, 955373959, 955374362, - 955374791, 955375246, 955375728, 955376235, 955376767, 955377324, 955377906, 955378513, - 955379143, 955379797, 955380474, 955381174, 955381896, 955382640, 955383406, 955384192, - 955385000, 955385827, 955386674, 955387540, 955388424, 955389326, 955390246, 955391183, - 955392136, 955393105, 955394089, 955395088, 955396100, 955397126, 955398165, 955399216, - 955400278, 955401351, 955402435, 955403528, 955404629, 955405740, 955406857, 955407982, - 955409113, 955410249, 955411390, 955412535, 955413684, 955414836, 955415989, 955417144 -}; - -/** - * Set DDS frequency tuning word. The output frequency is equal to RefClock * (ftw / 2 ^ 32). - * - * @param ftw Frequency Tuning Word - */ -void ddsSetFTW (uint32_t ftw) -{ - int x = ftw - freqTable[0]; - putchar (x > 0 ? 0xc0 : 0x40); -} - -/** @} */ - /** * @defgroup sys System Library Functions * @@ -400,7 +324,7 @@ void timeUpdate() // Setup the next interrupt for the operational mode. timeCompare += TIME_RATE; - ddsSetFTW (freqTable[timeNCO >> 8]); + putchar ((timeNCO >> 8) < 0x80 ? 0xc0 : 0x40); timeNCO += timeNCOFreq; @@ -446,22 +370,6 @@ typedef enum TNC_TX_END } TNC_TX_1200BPS_STATE; -/// Enumeration of the messages we can transmit. -typedef enum -{ - /// Startup message that contains software version information. - TNC_BOOT_MESSAGE, - - /// Plain text status message. - TNC_STATUS, - - /// Message that contains GPS NMEA-0183 $GPGGA message. - TNC_GGA, - - /// Message that contains GPS NMEA-0183 $GPRMC message. - TNC_RMC -} TNC_MESSAGE_TYPE; - /// AX.25 compliant packet header that contains destination, station call sign, and path. /// 0x76 for SSID-11, 0x78 for SSID-12 uint8_t TNC_AX25_HEADER[30] = { @@ -471,7 +379,6 @@ uint8_t TNC_AX25_HEADER[30] = { 'W' << 1, 'I' << 1, 'D' << 1, 'E' << 1, '3' << 1, ' ' << 1, 0x67, \ 0x03, 0xf0 }; - /// The next bit to transmit. uint8_t tncTxBit; @@ -496,9 +403,6 @@ uint8_t tncBitStuff; /// Pointer to TNC buffer as we save each byte during message preparation. uint8_t *tncBufferPnt; -/// The type of message to tranmit in the next packet. -TNC_MESSAGE_TYPE tncPacketType; - /// Buffer to hold the message portion of the AX.25 packet as we prepare it. uint8_t tncBuffer[TNC_BUFFER_SIZE]; @@ -509,7 +413,6 @@ void tncInit() { tncTxBit = 0; tncMode = TNC_TX_READY; - tncPacketType = TNC_BOOT_MESSAGE; } /** -- 2.30.2