-/**
+/**
* 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>
-#include <math.h>
// Public methods, constants, and data structures for each class.
{
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 );
/// 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[] = {
+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,
#define TNC_CALLSIGN_OFF 7
#define TNC_CALLSIGN_LEN 6
+#define TNC_SSID_OFF 13
static void
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
}
/// 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()
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;
}
}
-/**
- * Generate the plain text position packet.
- */
-static int tncPositionPacket(void)
+static int ao_num_sats(void)
{
- int32_t latitude = ao_gps_data.latitude;
- int32_t longitude = ao_gps_data.longitude;
- int32_t altitude = ao_gps_data.altitude;
- uint8_t *buf;
-
- if (altitude < 0)
- altitude = 0;
- altitude = (altitude * (int32_t) 10000 + (3048/2)) / (int32_t) 3048;
-
-#if 0
- char lat_sign = 'N', lon_sign = 'E';
- 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 (latitude < 0) {
- lat_sign = 'S';
- latitude = -latitude;
- }
+ int i;
+ int n = 0;
- if (longitude < 0) {
- lon_sign = 'W';
- longitude = -longitude;
+ for (i = 0; i < ao_gps_tracking_data.channels; i++) {
+ if (ao_gps_tracking_data.sats[i].svid)
+ n++;
}
+ return n;
+}
- /* Round latitude and longitude by 0.005 minutes */
- latitude = latitude + 833;
- if (latitude > 900000000)
- latitude = 900000000;
- longitude = longitude + 833;
- if (longitude > 1800000000)
- longitude = 1800000000;
-
- lat_deg = latitude / 10000000;
- latitude -= lat_deg * 10000000;
- latitude *= 60;
- lat_min = latitude / 10000000;
- latitude -= lat_min * 10000000;
- lat_frac = latitude / 100000;
-
- lon_deg = longitude / 10000000;
- longitude -= lon_deg * 10000000;
- longitude *= 60;
- lon_min = longitude / 10000000;
- longitude -= lon_min * 10000000;
- lon_frac = longitude / 100000;
-
-#if 0
- 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);
+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 *) tncBuffer, "/%02u%02u%02uh%02u%02u.%02u%c/%03u%02u.%02u%c'/A=%06u\015",
- ao_gps_data.hour,
- ao_gps_data.minute,
- ao_gps_data.second,
- lat_deg, lat_min, lat_frac, lat_sign,
- lon_deg, lon_min, lon_frac, lon_sign,
- altitude);
+ 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)
+{
+ 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;
+ }
+
buf = tncBuffer;
-#if APRS_TIME
- sprintf ((char *) buf, "/%02u%02u%02uh",
- ao_gps_data.hour,
- ao_gps_data.minute,
- ao_gps_data.second);
- buf += 8;
+
+#ifdef AO_APRS_TEST
+#define AO_APRS_FORMAT_COMPRESSED 0
+#define AO_APRS_FORMAT_UNCOMPRESSED 1
+ switch (AO_APRS_FORMAT_COMPRESSED) {
#else
- *buf++ = '!';
+ switch (ao_config.aprs_format) {
#endif
+ case AO_APRS_FORMAT_COMPRESSED:
+ default:
+ {
+ int32_t lat, lon, alt;
- /* Symbol table ID */
- *buf++ = '/';
+ *buf++ = '!';
- latitude = ((uint64_t) 380926 * (900000000 - latitude)) / 10000000;
- longitude = ((uint64_t) 190463 * (1800000000 + longitude)) / 10000000;
+ /* Symbol table ID */
+ *buf++ = '/';
-#define ALTITUDE_LOG_BASE 0.001998002662673f /* log(1.002) */
+ lat = ((uint64_t) 380926 * (900000000 - latitude)) / 10000000;
+ lon = ((uint64_t) 190463 * (1800000000 + longitude)) / 10000000;
- altitude = logf((float) altitude) * (1/ALTITUDE_LOG_BASE);
+ alt = ao_aprs_encode_altitude(altitude);
- tncCompressInt(buf, latitude, 4);
- buf += 4;
- tncCompressInt(buf, longitude, 4);
- buf += 4;
+ tncCompressInt(buf, lat, 4);
+ buf += 4;
+ tncCompressInt(buf, lon, 4);
+ buf += 4;
- /* Symbol code */
- *buf++ = '\'';
+ /* Symbol code */
+ *buf++ = '\'';
- tncCompressInt(buf, altitude, 2);
- buf += 2;
+ 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;
+ }
+ }
+
+ buf += tncComment(buf);
- *buf++ = 33 + ((1 << 5) | (2 << 3));
- *buf++ = '\0';
return buf - tncBuffer;
}
return l;
}
-/**
+/**
* Prepare an AX.25 data packet. Each time this method is called, it automatically
* rotates through 1 of 3 messages.
*
projects / fw / altos / blobdiff