-/**
- * Convert frequency in hertz to 32-bit DDS FTW (Frequency Tune Word).
- *
- * @param freq frequency in Hertz
- *
- */
-void ddsSetFreq(uint32_t freq)
-{
- uint8_t i;
- uint32_t ftw;
-
- // To avoid rounding errors with floating point math, we do a long multiply on the data.
- ftw = freq * DDS_MULT[0];
-
- for (i = 0; i < DDS_FREQ_TO_FTW_DIGITS - 1; ++i)
- ftw += (freq * DDS_MULT[i+1]) / DDS_DIVISOR[i];
-
- ddsSetFTW (ftw);
-}
-
-/**
- * Set DDS frequency tuning word for the FSK 0 and 1 values. The output frequency is equal
- * to RefClock * (ftw / 2 ^ 32).
- *
- * @param ftw0 frequency tuning word for the FSK 0 value
- * @param ftw1 frequency tuning word for the FSK 1 value
- */
-void ddsSetFSKFreq (uint32_t ftw0, uint32_t ftw1)
-{
-// printf ("ftw0 %d ftw1 %d\n", ftw0, ftw1);
-}
-
-/**
- * Set the DDS to run in A-FSK, FSK, or PSK31 mode
- *
- * @param mode DDS_MODE_APRS, DDS_MODE_PSK31, or DDS_MODE_HF_APRS constant
- */
-void ddsSetMode (DDS_MODE mode)
-{
-// printf ("mode %d\n", mode);
-}
-
-/** @} */
-
-/**
- * @defgroup GPS Motorola M12+ GPS Engine
- *
- * Functions to control the Motorola M12+ GPS engine in native binary protocol mode.
- *
- * @{
- */
-
-/// The maximum length of a binary GPS engine message.
-#define GPS_BUFFER_SIZE 50
-
-/// GPS parse engine state machine values.
-typedef enum
-{
- /// 1st start character '@'
- GPS_START1,
-
- /// 2nd start character '@'
- GPS_START2,
-
- /// Upper case 'A' - 'Z' message type
- GPS_COMMAND1,
-
- /// Lower case 'a' - 'z' message type
- GPS_COMMAND2,
-
- /// 0 - xx bytes based on message type 'Aa'
- GPS_READMESSAGE,
-
- /// 8-bit checksum
- GPS_CHECKSUMMESSAGE,
-
- /// End of message - Carriage Return
- GPS_EOMCR,
-
- /// End of message - Line Feed
- GPS_EOMLF
-} GPS_PARSE_STATE_MACHINE;
-
-/// Index into gpsBuffer used to store message data.
-uint8_t gpsIndex;
-
-/// State machine used to parse the GPS message stream.
-GPS_PARSE_STATE_MACHINE gpsParseState;
-
-/// Buffer to store data as it is read from the GPS engine.
-uint8_t gpsBuffer[GPS_BUFFER_SIZE];
-
-/// Peak altitude detected while GPS is in 3D fix mode.
-int32_t gpsPeakAltitude;
-
-/// Checksum used to verify binary message from GPS engine.
-uint8_t gpsChecksum;
-
-/// Last verified GPS message received.
-GPSPOSITION_STRUCT gpsPosition;
-
-/**
- * Get the type of fix.
- *
- * @return gps fix type enumeration
- */
-GPS_FIX_TYPE gpsGetFixType()
-{
- // The upper 3-bits determine the fix type.
- switch (gpsPosition.status & 0xe000)
- {
- case 0xe000:
- return GPS_3D_FIX;
-
- case 0xc000:
- return GPS_2D_FIX;
-
- default:
- return GPS_NO_FIX;
- } // END switch
-}
-
-/**
- * Peak altitude detected while GPS is in 3D fix mode since the system was booted.
- *
- * @return altitude in feet
- */
-int32_t gpsGetPeakAltitude()
-{
- return gpsPeakAltitude;
-}
-
-/**
- * Initialize the GPS subsystem.
- */
-void gpsInit()
-{
- // Initial parse state.
- gpsParseState = GPS_START1;
-
- // Assume we start at sea level.
- gpsPeakAltitude = 0;
-
- // Clear the structure that stores the position message.
- memset (&gpsPosition, 0, sizeof(GPSPOSITION_STRUCT));
-
- // Setup the timers used to measure the 1-PPS time period.
-// setup_timer_3(T3_INTERNAL | T3_DIV_BY_1);
-// setup_ccp2 (CCP_CAPTURE_RE | CCP_USE_TIMER3);
-}
-
-/**
- * Determine if new GPS message is ready to process. This function is a one shot and
- * typically returns true once a second for each GPS position fix.
- *
- * @return true if new message available; otherwise false
- */
-bool_t gpsIsReady()
-{
- return true;
- if (gpsPosition.updateFlag)
- {
- gpsPosition.updateFlag = false;
- return true;
- } // END if
-
- return false;
-}
-
-/**
- * Calculate NMEA-0183 message checksum of buffer that is length bytes long.
- *
- * @param buffer pointer to data buffer.
- * @param length number of bytes in buffer.
- *
- * @return checksum of buffer
- */
-uint8_t gpsNMEAChecksum (uint8_t *buffer, uint8_t length)
-{
- uint8_t i, checksum;
-
- checksum = 0;
-
- for (i = 0; i < length; ++i)
- checksum ^= buffer[i];
-
- return checksum;
-}
-
-/**
- * Verify the GPS engine is sending the @@Hb position report message. If not,
- * configure the GPS engine to send the desired report.
- *
- * @return true if GPS engine operation; otherwise false
- */
-bool_t gpsSetup()
-{
- uint8_t startTime, retryCount;
-
- // We wait 10 seconds for the GPS engine to respond to our message request.
- startTime = timeGetTicks();
- retryCount = 0;
-
- while (++retryCount < 10)
- {
- // Read the serial FIFO and process the GPS messages.
-// gpsUpdate();
-
- // If a GPS data set is available, then GPS is operational.
- if (gpsIsReady())
- {
-// timeSetDutyCycle (TIME_DUTYCYCLE_10);
- return true;
- }
-
- if (timeGetTicks() > startTime)
- {
- puts ("@@Hb\001\053\015\012");
- startTime += 10;
- } // END if
-
- } // END while
-
- return false;
-}
-
-/**
- * Parse the Motorola @@Hb (Short position/message) report.
- */
-void gpsParsePositionMessage()
-{
- // Convert the binary stream into data elements. We will scale to the desired units
- // as the values are used.
- gpsPosition.updateFlag = true;
-
- gpsPosition.month = gpsBuffer[0];
- gpsPosition.day = gpsBuffer[1];
- gpsPosition.year = ((uint16_t) gpsBuffer[2] << 8) | gpsBuffer[3];
- gpsPosition.hours = gpsBuffer[4];
- gpsPosition.minutes = gpsBuffer[5];
- gpsPosition.seconds = gpsBuffer[6];
- gpsPosition.latitude = ((int32) gpsBuffer[11] << 24) | ((int32) gpsBuffer[12] << 16) | ((int32) gpsBuffer[13] << 8) | (int32) gpsBuffer[14];
- gpsPosition.longitude = ((int32) gpsBuffer[15] << 24) | ((int32) gpsBuffer[16] << 16) | ((int32) gpsBuffer[17] << 8) | gpsBuffer[18];
- gpsPosition.altitudeCM = ((int32) gpsBuffer[19] << 24) | ((int32) gpsBuffer[20] << 16) | ((int32) gpsBuffer[21] << 8) | gpsBuffer[22];
- gpsPosition.altitudeFeet = gpsPosition.altitudeCM * 100l / 3048l;
- gpsPosition.vSpeed = ((uint16_t) gpsBuffer[27] << 8) | gpsBuffer[28];
- gpsPosition.hSpeed = ((uint16_t) gpsBuffer[29] << 8) | gpsBuffer[30];
- gpsPosition.heading = ((uint16_t) gpsBuffer[31] << 8) | gpsBuffer[32];
- gpsPosition.dop = ((uint16_t) gpsBuffer[33] << 8) | gpsBuffer[34];
- gpsPosition.visibleSats = gpsBuffer[35];
- gpsPosition.trackedSats = gpsBuffer[36];
- gpsPosition.status = ((uint16_t) gpsBuffer[37] << 8) | gpsBuffer[38];
-
- // Update the peak altitude if we have a valid 3D fix.
- if (gpsGetFixType() == GPS_3D_FIX)
- if (gpsPosition.altitudeFeet > gpsPeakAltitude)
- gpsPeakAltitude = gpsPosition.altitudeFeet;
-}
-
-/**
- * Turn on the GPS engine power and serial interface.
- */
-void gpsPowerOn()
-{
- // 3.0 VDC LDO control line.
-// output_high (IO_GPS_PWR);
-
-}
-
-/**
- * Turn off the GPS engine power and serial interface.
- */
-void gpsPowerOff()
-{
- // 3.0 VDC LDO control line.
-// output_low (IO_GPS_PWR);
-}
-