-/**
+/**
* 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.
* (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),
* (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.
*
* (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.
- *
+ *
*
* 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.
* @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 <ao.h>
+
+#if !HAS_APRS
+#error HAS_APRS not set
+#endif
#endif
#include <ao_aprs.h>
-typedef int bool_t;
-typedef int32_t int32;
-#define false 0
-#define true 1
-
// Public methods, constants, and data structures for each class.
-void ddsInit();
-void ddsSetAmplitude (uint8_t amplitude);
-void ddsSetOutputScale (uint16_t amplitude);
-void ddsSetFSKFreq (uint32_t ftw0, uint32_t ftw1);
-void ddsSetFreq (uint32_t freq);
-void ddsSetFTW (uint32_t ftw);
-
-uint16_t sysCRC16(uint8_t *buffer, uint8_t length, uint16_t crc);
-
-uint8_t timeGetTicks();
-void timeInit();
-void timeSetDutyCycle (uint8_t dutyCycle);
-void timeUpdate();
-
-void tncInit();
-bool_t tncIsFree();
-void tncHighRate(bool_t state);
-void tnc1200TimerTick();
-void tncTxByte (uint8_t value);
-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 };
+static void timeInit(void);
-/// 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);
-}
+static void tncInit(void);
+static void tnc1200TimerTick(void);
/** @} */
*
* @return CRC-16 of buffer[0 .. length]
*/
-uint16_t sysCRC16(uint8_t *buffer, uint8_t length, uint16_t crc)
+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 );
* @{
*/
-/// A counter that ticks every 100mS.
-uint8_t timeTicks;
-
-/// Counts the number of 104uS interrupts for a 100mS time period.
-uint16_t timeInterruptCount;
-
-/// Counts the number of 100mS time periods in 1 second.
-uint8_t time100ms;
-
-/// System time in seconds.
-uint8_t timeSeconds;
-
-/// System time in minutes.
-uint8_t timeMinutes;
-
-/// System time in hours.
-uint8_t timeHours;
-
-/// Desired LED duty cycle 0 to 9 where 0 = 0% and 9 = 90%.
-uint8_t timeDutyCycle;
-
-/// Current value of the timer 1 compare register used to generate 104uS interrupt rate (9600bps).
-uint16_t timeCompare;
-
/// 16-bit NCO where the upper 8-bits are used to index into the frequency generation table.
-uint16_t timeNCO;
+static uint16_t timeNCO;
/// Audio tone NCO update step (phase).
-uint16_t timeNCOFreq;
-
-/// Counter used to deciminate down from the 104uS to 833uS interrupt rate. (9600 to 1200 baud)
-uint8_t timeLowRateCount;
-
-/// Flag set true once per second.
-bool_t timeUpdateFlag;
-
-/// Flag that indicate the flight time should run.
-bool_t timeRunFlag;
-
-/// The change in the CCP_1 register for each 104uS (9600bps) interrupt period.
-#define TIME_RATE 125
-
-/**
- * Running 8-bit counter that ticks every 100mS.
- *
- * @return 100mS time tick
- */
-uint8_t timeGetTicks()
-{
- return timeTicks;
-}
+static uint16_t timeNCOFreq;
/**
* Initialize the real-time clock.
*/
-void timeInit()
+static void timeInit()
{
- timeTicks = 0;
- timeInterruptCount = 0;
-// time100mS = 0;
- timeSeconds = 0;
- timeMinutes = 0;
- timeHours = 0;
- timeCompare = TIME_RATE;
- timeUpdateFlag = false;
timeNCO = 0x00;
- timeLowRateCount = 0;
timeNCOFreq = 0x2000;
- timeRunFlag = false;
-}
-
-/**
- * Function return true once a second based on real-time clock.
- *
- * @return true on one second tick; otherwise false
- */
-bool_t timeIsUpdate()
-{
- if (timeUpdateFlag)
- {
- timeUpdateFlag = false;
- return true;
- } // END if
-
- return false;
-}
-
-/**
- * Set a flag to indicate the flight time should run. This flag is typically set when the payload
- * lifts off.
- */
-void timeSetRunFlag()
-{
- timeRunFlag = true;
-}
-
-/**
- * Timer interrupt handler called every 104uS (9600 times/second).
- */
-void timeUpdate()
-{
- // Setup the next interrupt for the operational mode.
- timeCompare += TIME_RATE;
-
- ddsSetFTW (freqTable[timeNCO >> 8]);
-
- timeNCO += timeNCOFreq;
-
- if (++timeLowRateCount == 8)
- {
- timeLowRateCount = 0;
- tnc1200TimerTick();
- } // END if
}
/** @} */
#define TNC_TX_DELAY 45
/// The size of the TNC output buffer.
-#define TNC_BUFFER_SIZE 80
+#define TNC_BUFFER_SIZE 40
/// States that define the current mode of the 1200 bps (A-FSK) state machine.
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] = {
- 'A' << 1, 'P' << 1, 'R' << 1, 'S' << 1, ' ' << 1, ' ' << 1, 0x60, \
- 'K' << 1, 'D' << 1, '7' << 1, 'S' << 1, 'Q' << 1, 'G' << 1, 0x76, \
- 'G' << 1, 'A' << 1, 'T' << 1, 'E' << 1, ' ' << 1, ' ' << 1, 0x60, \
- 'W' << 1, 'I' << 1, 'D' << 1, 'E' << 1, '3' << 1, ' ' << 1, 0x67, \
+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++) {
+ if (!ao_config.callsign[i])
+ break;
+ TNC_AX25_HEADER[TNC_CALLSIGN_OFF + i] = ao_config.callsign[i] << 1;
+ }
+ 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.
-uint8_t tncTxBit;
+static uint8_t tncTxBit;
/// Current mode of the 1200 bps state machine.
-TNC_TX_1200BPS_STATE tncMode;
+static TNC_TX_1200BPS_STATE tncMode;
/// Counter for each bit (0 - 7) that we are going to transmit.
-uint8_t tncBitCount;
+static uint8_t tncBitCount;
/// A shift register that holds the data byte as we bit shift it for transmit.
-uint8_t tncShift;
+static uint8_t tncShift;
/// Index into the APRS header and data array for each byte as we transmit it.
-uint8_t tncIndex;
+static uint8_t tncIndex;
/// The number of bytes in the message portion of the AX.25 message.
-uint8_t tncLength;
+static uint8_t tncLength;
/// A copy of the last 5 bits we've transmitted to determine if we need to bit stuff on the next bit.
-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;
+static uint8_t tncBitStuff;
/// Buffer to hold the message portion of the AX.25 packet as we prepare it.
-uint8_t tncBuffer[TNC_BUFFER_SIZE];
-
-/// Flag that indicates we want to transmit every 5 seconds.
-bool_t tncHighRateFlag;
+static uint8_t tncBuffer[TNC_BUFFER_SIZE];
-/**
+/**
* Initialize the TNC internal variables.
*/
-void tncInit()
+static void tncInit()
{
tncTxBit = 0;
tncMode = TNC_TX_READY;
- tncPacketType = TNC_BOOT_MESSAGE;
- tncHighRateFlag = false;
-}
-
-/**
- * Determine if the hardware if ready to transmit a 1200 baud packet.
- *
- * @return true if ready; otherwise false
- */
-bool_t tncIsFree()
-{
- if (tncMode == TNC_TX_READY)
- return true;
-
- return false;
-}
-
-void tncHighRate(bool_t state)
-{
- tncHighRateFlag = state;
-}
-
-/**
- * Determine if the seconds value timeSeconds is a valid time slot to transmit
- * a message. Time seconds is in UTC.
- *
- * @param timeSeconds UTC time in seconds
- *
- * @return true if valid time slot; otherwise false
- */
-bool_t tncIsTimeSlot (uint8_t timeSeconds)
-{
- if (tncHighRateFlag)
- {
- if ((timeSeconds % 5) == 0)
- return true;
-
- return false;
- } // END if
-
- switch (timeSeconds)
- {
- case 0:
- case 15:
- case 30:
- case 45:
- return true;
-
- default:
- return false;
- } // END switch
}
/**
* Method that is called every 833uS to transmit the 1200bps A-FSK data stream.
* The provides the pre and postamble as well as the bit stuffed data stream.
*/
-void tnc1200TimerTick()
+static void tnc1200TimerTick()
{
// Set the A-FSK frequency.
if (tncTxBit == 0x00)
else
timeNCOFreq = 0x3aab;
- switch (tncMode)
+ switch (tncMode)
{
case TNC_TX_READY:
// Generate a test signal alteranting between high and low tones.
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];
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;
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];
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;
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;
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;
}
// 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;
} // END switch
}
-/**
- * Method that is called every 104uS to transmit the 9600bps FSK data stream.
+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?).
*/
-void tnc9600TimerTick()
+
+#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. Data is written through the tncTxByte
- * callback function
+ * Generate the plain text position packet.
*/
-void tncPositionPacket(void)
+static int tncPositionPacket(void)
{
- int32_t latitude = 45.4694766 * 10000000;
- int32_t longitude = -122.7376250 * 10000000;
- uint32_t altitude = 10000;
- uint16_t lat_deg;
- uint16_t lon_deg;
- uint16_t lat_min;
- uint16_t lat_frac;
- uint16_t lon_min;
- uint16_t lon_frac;
- int c;
-
- 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;
+ }
+
+ /* 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;
+ }
}
- 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;
-
- c = sprintf ((char *) tncBufferPnt, "=%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 * 100 / 3048);
- tncBufferPnt += c;
- tncLength += c;
+ buf += tncComment(buf);
+
+ return buf - tncBuffer;
}
-/**
+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.
*
* @param dataMode enumerated type that specifies 1200bps A-FSK or 9600bps FSK
*/
-void tncTxPacket(void)
+void ao_aprs_send(void)
{
uint16_t crc;
- // Set a pointer to our TNC output buffer.
- tncBufferPnt = tncBuffer;
-
- // Set the message length counter.
- tncLength = 0;
+ timeInit();
+ tncInit();
+ tncSetCallsign();
- tncPositionPacket();
+ tncLength = tncPositionPacket();
// Calculate the CRC for the header and message.
crc = sysCRC16(TNC_AX25_HEADER, sizeof(TNC_AX25_HEADER), 0xffff);
crc = sysCRC16(tncBuffer, tncLength, crc ^ 0xffff);
// Save the CRC in the message.
- *tncBufferPnt++ = crc & 0xff;
- *tncBufferPnt = (crc >> 8) & 0xff;
-
- // Update the length to include the CRC bytes.
- tncLength += 2;
+ tncBuffer[tncLength++] = crc & 0xff;
+ tncBuffer[tncLength++] = (crc >> 8) & 0xff;
// Prepare the variables that are used in the real-time clock interrupt.
tncBitCount = 0;
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);
-
- // Log the battery and reference voltage just after we key the transmitter.
-// sysLogVoltage();
- while (tncMode != TNC_TX_READY)
- timeUpdate();
+ ao_radio_send_aprs(tncFill);
}
/** @} */
projects / fw / altos / blobdiff