X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=blobdiff_plain;f=src%2Fdrivers%2Fao_aprs.c;h=2f17d04401eade3379e538874870991c3ba1bd04;hp=e3abe52eff9758eb0e6984d5a7888591c3a38d16;hb=382b3ef62a09e580834b07faf9ed2d00e5ce1621;hpb=1f797066857b171b19829e2bb7187b8faf37d07c diff --git a/src/drivers/ao_aprs.c b/src/drivers/ao_aprs.c index e3abe52e..2f17d044 100644 --- a/src/drivers/ao_aprs.c +++ b/src/drivers/ao_aprs.c @@ -1,11 +1,11 @@ -/** +/** * http://ad7zj.net/kd7lmo/aprsbeacon_code.html * * @mainpage Pico Beacon * * @section overview_sec Overview * - * The Pico Beacon is an APRS based tracking beacon that operates in the UHF 420-450MHz band. The device utilizes a + * The Pico Beacon is an APRS based tracking beacon that operates in the UHF 420-450MHz band. The device utilizes a * Microchip PIC 18F2525 embedded controller, Motorola M12+ GPS engine, and Analog Devices AD9954 DDS. The device is capable * of generating a 1200bps A-FSK and 9600 bps FSK AX.25 compliant APRS (Automatic Position Reporting System) message. @@ -24,7 +24,7 @@ * (4) corrected size of LOG_COORD block when searching for end of log. * * @subsection v303 V3.03 - * 15 Sep 2005, Change include; (1) removed AD9954 setting SDIO as input pin, + * 15 Sep 2005, Change include; (1) removed AD9954 setting SDIO as input pin, * (2) additional comments and Doxygen tags, * (3) integration and test code calculates DDS FTW, * (4) swapped bus and reference analog input ports (hardware change), @@ -38,7 +38,7 @@ * (2) Doxygen documentation clean up and additions, and * (3) added integration and test code to baseline. * - * + * * @subsection v301 V3.01 * 13 Jan 2005, Renamed project and files to Pico Beacon. * @@ -54,28 +54,28 @@ * (8) added flight data recorder, and * (9) added diagnostics terminal mode. * - * + * * @subsection v201 V2.01 - * 30 Jan 2004, Change include; (1) General clean up of in-line documentation, and + * 30 Jan 2004, Change include; (1) General clean up of in-line documentation, and * (2) changed temperature resolution to 0.1 degrees F. * - * + * * @subsection v200 V2.00 * 26 Oct 2002, Change include; (1) Micro Beacon II hardware changes including PIC18F252 processor, - * (2) serial EEPROM, - * (3) GPS power control, - * (4) additional ADC input, and - * (5) LM60 temperature sensor. + * (2) serial EEPROM, + * (3) GPS power control, + * (4) additional ADC input, and + * (5) LM60 temperature sensor. * * * @subsection v101 V1.01 - * 5 Dec 2001, Change include; (1) Changed startup message, and + * 5 Dec 2001, Change include; (1) Changed startup message, and * (2) applied SEPARATE pragma to several methods for memory usage. * * * @subsection v100 V1.00 * 25 Sep 2001, Initial release. Flew ANSR-3 and ANSR-4. - * + * * @@ -102,11 +102,11 @@ * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - * + * - * - * + * + * * @section design Design Details * * Provides design details on a variety of the components that make up the Pico Beacon. @@ -118,29 +118,33 @@ * @page power Power Consumption * * Measured DC power consumption. - * - * 3VDC prime power current + * + * 3VDC prime power current * - * 7mA Held in reset + * 7mA Held in reset - * 18mA Processor running, all I/O off + * 18mA Processor running, all I/O off - * 110mA GPS running + * 110mA GPS running - * 120mA GPS running w/antenna + * 120mA GPS running w/antenna - * 250mA DDS running and GPS w/antenna + * 250mA DDS running and GPS w/antenna - * 420mA DDS running, GPS w/antenna, and PA chain on with no RF + * 420mA DDS running, GPS w/antenna, and PA chain on with no RF - * 900mA Transmit + * 900mA Transmit * */ #ifndef AO_APRS_TEST #include + +#if !HAS_APRS +#error HAS_APRS not set +#endif #endif #include @@ -176,11 +180,11 @@ static uint16_t sysCRC16(const uint8_t *buffer, uint8_t length, uint16_t crc) { uint8_t i, bit, value; - for (i = 0; i < length; ++i) + for (i = 0; i < length; ++i) { value = buffer[i]; - for (bit = 0; bit < 8; ++bit) + for (bit = 0; bit < 8; ++bit) { crc ^= (value & 0x01); crc = ( crc & 0x01 ) ? ( crc >> 1 ) ^ 0x8408 : ( crc >> 1 ); @@ -253,18 +257,20 @@ typedef enum /// AX.25 compliant packet header that contains destination, station call sign, and path. /// 0x76 for SSID-11, 0x78 for SSID-12 -static uint8_t TNC_AX25_HEADER[] = { - 'A' << 1, 'P' << 1, 'A' << 1, 'M' << 1, ' ' << 1, ' ' << 1, 0x60, \ - 'N' << 1, '0' << 1, 'C' << 1, 'A' << 1, 'L' << 1, 'L' << 1, 0x78, \ - 'W' << 1, 'I' << 1, 'D' << 1, 'E' << 1, '2' << 1, ' ' << 1, 0x65, \ +static uint8_t TNC_AX25_HEADER[] = { + 'A' << 1, 'P' << 1, 'A' << 1, 'M' << 1, ' ' << 1, ' ' << 1, 0x60, + 'N' << 1, '0' << 1, 'C' << 1, 'A' << 1, 'L' << 1, 'L' << 1, 0x78, + 'W' << 1, 'I' << 1, 'D' << 1, 'E' << 1, '2' << 1, ' ' << 1, 0x65, 0x03, 0xf0 }; #define TNC_CALLSIGN_OFF 7 #define TNC_CALLSIGN_LEN 6 +#define TNC_SSID_OFF 13 static void tncSetCallsign(void) { +#ifndef AO_APRS_TEST uint8_t i; for (i = 0; i < TNC_CALLSIGN_LEN; i++) { @@ -274,7 +280,10 @@ tncSetCallsign(void) } for (; i < TNC_CALLSIGN_LEN; i++) TNC_AX25_HEADER[TNC_CALLSIGN_OFF + i] = ' ' << 1; - + + /* Fill in the SSID with the low digit of the serial number */ + TNC_AX25_HEADER[TNC_SSID_OFF] = 0x60 | ((ao_config.aprs_ssid & 0xf) << 1); +#endif } /// The next bit to transmit. @@ -301,7 +310,7 @@ static uint8_t tncBitStuff; /// Buffer to hold the message portion of the AX.25 packet as we prepare it. static uint8_t tncBuffer[TNC_BUFFER_SIZE]; -/** +/** * Initialize the TNC internal variables. */ static void tncInit() @@ -322,7 +331,7 @@ static void tnc1200TimerTick() else timeNCOFreq = 0x3aab; - switch (tncMode) + switch (tncMode) { case TNC_TX_READY: // Generate a test signal alteranting between high and low tones. @@ -338,16 +347,16 @@ static void tnc1200TimerTick() else tncTxBit = 0; } - + // When the flag is done, determine if we need to send more or data. - if (++tncBitCount == 8) + if (++tncBitCount == 8) { tncBitCount = 0; tncShift = 0x7e; // Once we transmit x mS of flags, send the data. // txDelay bytes * 8 bits/byte * 833uS/bit = x mS - if (++tncIndex == TNC_TX_DELAY) + if (++tncIndex == TNC_TX_DELAY) { tncIndex = 0; tncShift = TNC_AX25_HEADER[0]; @@ -360,7 +369,7 @@ static void tnc1200TimerTick() case TNC_TX_HEADER: // Determine if we have sent 5 ones in a row, if we have send a zero. - if (tncBitStuff == 0x1f) + if (tncBitStuff == 0x1f) { if (tncTxBit == 0) tncTxBit = 1; @@ -380,17 +389,17 @@ static void tnc1200TimerTick() tncTxBit = 0; } - // Save the data stream so we can determine if bit stuffing is + // Save the data stream so we can determine if bit stuffing is // required on the next bit time. tncBitStuff = ((tncBitStuff << 1) | (tncShift & 0x01)) & 0x1f; // If all the bits were shifted, get the next byte. - if (++tncBitCount == 8) + if (++tncBitCount == 8) { tncBitCount = 0; // After the header is sent, then send the data. - if (++tncIndex == sizeof(TNC_AX25_HEADER)) + if (++tncIndex == sizeof(TNC_AX25_HEADER)) { tncIndex = 0; tncShift = tncBuffer[0]; @@ -405,7 +414,7 @@ static void tnc1200TimerTick() case TNC_TX_DATA: // Determine if we have sent 5 ones in a row, if we have send a zero. - if (tncBitStuff == 0x1f) + if (tncBitStuff == 0x1f) { if (tncTxBit == 0) tncTxBit = 1; @@ -425,17 +434,17 @@ static void tnc1200TimerTick() tncTxBit = 0; } - // Save the data stream so we can determine if bit stuffing is + // Save the data stream so we can determine if bit stuffing is // required on the next bit time. tncBitStuff = ((tncBitStuff << 1) | (tncShift & 0x01)) & 0x1f; // If all the bits were shifted, get the next byte. - if (++tncBitCount == 8) + if (++tncBitCount == 8) { tncBitCount = 0; // If everything was sent, transmit closing flags. - if (++tncIndex == tncLength) + if (++tncIndex == tncLength) { tncIndex = 0; tncShift = 0x7e; @@ -450,7 +459,7 @@ static void tnc1200TimerTick() case TNC_TX_END: // The variable tncShift contains the lastest data byte. - // NRZI enocde the data stream. + // NRZI enocde the data stream. if ((tncShift & 0x01) == 0x00) { if (tncTxBit == 0) tncTxBit = 1; @@ -459,13 +468,13 @@ static void tnc1200TimerTick() } // If all the bits were shifted, get the next one. - if (++tncBitCount == 8) + if (++tncBitCount == 8) { tncBitCount = 0; tncShift = 0x7e; - + // Transmit two closing flags. - if (++tncIndex == 2) + if (++tncIndex == 2) { tncMode = TNC_TX_READY; @@ -478,57 +487,334 @@ static void tnc1200TimerTick() } // END switch } +static void tncCompressInt(uint8_t *dest, int32_t value, int len) { + int i; + for (i = len - 1; i >= 0; i--) { + dest[i] = value % 91 + 33; + value /= 91; + } +} + +static int ao_num_sats(void) +{ + int i; + int n = 0; + + for (i = 0; i < ao_gps_tracking_data.channels; i++) { + if (ao_gps_tracking_data.sats[i].svid) + n++; + } + return n; +} + +static char ao_gps_locked(void) +{ + if (ao_gps_data.flags & AO_GPS_VALID) + return 'L'; + else + return 'U'; +} + +static int tncComment(uint8_t *buf) +{ +#if HAS_ADC + struct ao_data packet; + + ao_arch_critical(ao_data_get(&packet);); + + int16_t battery = ao_battery_decivolt(packet.adc.v_batt); +#ifdef AO_SENSE_DROGUE + int16_t apogee = ao_ignite_decivolt(AO_SENSE_DROGUE(&packet)); +#endif +#ifdef AO_SENSE_MAIN + int16_t main = ao_ignite_decivolt(AO_SENSE_MAIN(&packet)); +#endif + + return sprintf((char *) buf, + "%c%d B%d.%d" +#ifdef AO_SENSE_DROGUE + " A%d.%d" +#endif +#ifdef AO_SENSE_MAIN + " M%d.%d" +#endif + " %d" + , ao_gps_locked(), + ao_num_sats(), + battery/10, + battery % 10 +#ifdef AO_SENSE_DROGUE + , apogee/10, + apogee%10 +#endif +#ifdef AO_SENSE_MAIN + , main/10, + main%10 +#endif + , ao_serial_number + ); +#else + return sprintf((char *) buf, + "%c%d", + ao_gps_locked(), + ao_num_sats()); +#endif +} + +/* + * APRS use a log encoding of altitude with a base of 1.002, such that + * + * feet = 1.002 ** encoded_altitude + * + * meters = (1.002 ** encoded_altitude) * 0.3048 + * + * log2(meters) = log2(1.002 ** encoded_altitude) + log2(0.3048) + * + * log2(meters) = encoded_altitude * log2(1.002) + log2(0.3048) + * + * encoded_altitude = (log2(meters) - log2(0.3048)) / log2(1.002) + * + * encoded_altitude = (log2(meters) + log2(1/0.3048)) * (1/log2(1.002)) + * + * We need 9 bits of mantissa to hold 1/log2(1.002) (~ 347), which leaves us + * 23 bits of fraction. That turns out to be *just* enough to avoid any + * errors in the result (cool, huh?). + */ + +#define fixed23_int(x) ((uint32_t) ((x) << 23)) +#define fixed23_one fixed23_int(1) +#define fixed23_two fixed23_int(2) +#define fixed23_half (fixed23_one >> 1) +#define fixed23_floor(x) ((x) >> 23) +#define fixed23_real(x) ((uint32_t) ((x) * fixed23_one + 0.5)) + +static inline uint64_t +fixed23_mul(uint32_t x, uint32_t y) +{ + return ((uint64_t) x * y + fixed23_half) >> 23; +} + +/* + * Use 30 fraction bits for the altitude. We need two bits at the + * top as we need to handle x, where 0 <= x < 4. We don't + * need 30 bits, but it's actually easier this way as we normalize + * the incoming value to 1 <= x < 2, and having the integer portion + * way up high means we don't have to deal with shifting in both + * directions to cover from 0 to 2**30-1. + */ + +#define fixed30_int(x) ((uint32_t) ((x) << 30)) +#define fixed30_one fixed30_int(1) +#define fixed30_half (fixed30_one >> 1) +#define fixed30_two fixed30_int(2) + +static inline uint32_t +fixed30_mul(uint32_t x, uint32_t y) +{ + return ((uint64_t) x * y + fixed30_half) >> 30; +} + +/* + * Fixed point log2. Takes integer argument, returns + * fixed point result with 23 bits of fraction + */ + +static uint32_t +ao_fixed_log2(uint32_t x) +{ + uint32_t result; + uint32_t frac = fixed23_one; + + /* Bounds check for sanity */ + if (x <= 0) + return 0; + + if (x >= fixed30_one) + return 0xffffffff; + + /* + * Normalize and compute integer log portion + * + * This makes 1 <= x < 2, and computes result to be + * the integer portion of the log2 of x + */ + + for (result = fixed23_int(30); x < fixed30_one; result -= fixed23_one, x <<= 1) + ; + + /* + * Given x, find y and n such that: + * + * x = y * 2**n 1 <= y < 2 + * + * That means: + * + * lb(x) = n + lb(y) + * + * Now, repeatedly square y to find find z and m such that: + * + * z = y ** (2**m) 2 <= z < 4 + * + * This is possible because 1 <= y < 2 + * + * lb(y) = lb(z) / 2**m + * + * (1 + lb(z/2)) + * = ------------- + * 2**m + * + * = 2**-m + 2**-m * lb(z/2) + * + * Note that if 2 <= z < 4, then 1 <= (z/2) < 2, so we can + * iterate to find lb(z/2) + * + * In this implementation, we don't care about the 'm' value, + * instead we only care about 2**-m, which we store in 'frac' + */ + + while (frac != 0 && x != fixed30_one) { + /* Repeatedly square x until 2 <= x < 4 */ + while (x < fixed30_two) { + x = fixed30_mul(x, x); + + /* Divide the fractional result bit by 2 */ + frac >>= 1; + } + + /* Add in this result bit */ + result |= frac; + + /* Make 1 <= x < 2 again and iterate */ + x >>= 1; + } + return result; +} + +#define APRS_LOG_CONVERT fixed23_real(1.714065192056127) +#define APRS_LOG_BASE fixed23_real(346.920048461100941) + +static int +ao_aprs_encode_altitude(int meters) +{ + return fixed23_floor(fixed23_mul(ao_fixed_log2(meters) + APRS_LOG_CONVERT, APRS_LOG_BASE) + fixed23_half); +} + /** * Generate the plain text position packet. */ static int tncPositionPacket(void) { - int32_t latitude = ao_gps_data.latitude; - int32_t longitude = ao_gps_data.longitude; - int32_t altitude = ao_gps_data.altitude; - - uint16_t lat_deg; - uint16_t lon_deg; - uint16_t lat_min; - uint16_t lat_frac; - uint16_t lon_min; - uint16_t lon_frac; - - char lat_sign = 'N', lon_sign = 'E'; - - if (latitude < 0) { - lat_sign = 'S'; - latitude = -latitude; + static int32_t latitude; + static int32_t longitude; + static int32_t altitude; + uint8_t *buf; + + if (ao_gps_data.flags & AO_GPS_VALID) { + latitude = ao_gps_data.latitude; + longitude = ao_gps_data.longitude; + altitude = AO_TELEMETRY_LOCATION_ALTITUDE(&ao_gps_data); + if (altitude < 0) + altitude = 0; } - if (longitude < 0) { - lon_sign = 'W'; - longitude = -longitude; + buf = tncBuffer; + +#ifdef AO_APRS_TEST +#define AO_APRS_FORMAT_COMPRESSED 0 +#define AO_APRS_FORMAT_UNCOMPRESSED 1 + switch (AO_APRS_FORMAT_COMPRESSED) { +#else + switch (ao_config.aprs_format) { +#endif + case AO_APRS_FORMAT_COMPRESSED: + default: + { + int32_t lat, lon, alt; + + *buf++ = '!'; + + /* Symbol table ID */ + *buf++ = '/'; + + lat = ((uint64_t) 380926 * (900000000 - latitude)) / 10000000; + lon = ((uint64_t) 190463 * (1800000000 + longitude)) / 10000000; + + alt = ao_aprs_encode_altitude(altitude); + + tncCompressInt(buf, lat, 4); + buf += 4; + tncCompressInt(buf, lon, 4); + buf += 4; + + /* Symbol code */ + *buf++ = '\''; + + tncCompressInt(buf, alt, 2); + buf += 2; + + *buf++ = 33 + ((1 << 5) | (2 << 3)); + + break; } + case AO_APRS_FORMAT_UNCOMPRESSED: + { + char lat_sign = 'N', lon_sign = 'E'; + int32_t lat = latitude; + int32_t lon = longitude; + int32_t alt = altitude; + uint16_t lat_deg; + uint16_t lon_deg; + uint16_t lat_min; + uint16_t lat_frac; + uint16_t lon_min; + uint16_t lon_frac; + + if (lat < 0) { + lat_sign = 'S'; + lat = -lat; + } + + if (lon < 0) { + lon_sign = 'W'; + lon = -lon; + } - lat_deg = latitude / 10000000; - latitude -= lat_deg * 10000000; - latitude *= 60; - lat_min = latitude / 10000000; - latitude -= lat_min * 10000000; - lat_frac = (latitude + 50000) / 100000; - - lon_deg = longitude / 10000000; - longitude -= lon_deg * 10000000; - longitude *= 60; - lon_min = longitude / 10000000; - longitude -= lon_min * 10000000; - lon_frac = (longitude + 50000) / 100000; - - if (altitude < 0) - altitude = 0; - - altitude = altitude * (int32_t) 1000 / (int32_t) 3048; - - return sprintf ((char *) tncBuffer, "=%02u%02u.%02u%c\\%03u%02u.%02u%cO /A=%06u\015", - lat_deg, lat_min, lat_frac, lat_sign, - lon_deg, lon_min, lon_frac, lon_sign, - altitude); + /* Round latitude and longitude by 0.005 minutes */ + lat = lat + 833; + if (lat > 900000000) + lat = 900000000; + lon = lon + 833; + if (lon > 1800000000) + lon = 1800000000; + + lat_deg = lat / 10000000; + lat -= lat_deg * 10000000; + lat *= 60; + lat_min = lat / 10000000; + lat -= lat_min * 10000000; + lat_frac = lat / 100000; + + lon_deg = lon / 10000000; + lon -= lon_deg * 10000000; + lon *= 60; + lon_min = lon / 10000000; + lon -= lon_min * 10000000; + lon_frac = lon / 100000; + + /* Convert from meters to feet */ + alt = (alt * 328 + 50) / 100; + + buf += sprintf((char *) tncBuffer, "!%02u%02u.%02u%c/%03u%02u.%02u%c'/A=%06lu ", + lat_deg, lat_min, lat_frac, lat_sign, + lon_deg, lon_min, lon_frac, lon_sign, + (long) alt); + break; + } + } + + buf += tncComment(buf); + + return buf - tncBuffer; } static int16_t @@ -553,7 +839,7 @@ tncFill(uint8_t *buf, int16_t len) return l; } -/** +/** * Prepare an AX.25 data packet. Each time this method is called, it automatically * rotates through 1 of 3 messages. * @@ -584,7 +870,7 @@ void ao_aprs_send(void) tncIndex = 0; tncMode = TNC_TX_SYNC; - ao_radio_send_lots(tncFill); + ao_radio_send_aprs(tncFill); } /** @} */