- // Display the results of any user requests or commands.
- if (showSettingsFlag)
- {
- showSettingsFlag = false;
-
- fprintf (PC_HOST, "%03ld.%03ld MHz ", freqHz / 1000000, (freqHz / 1000) % 1000);
- fprintf (PC_HOST, "%d.%01ddBc\n\r", amplitude / 10, amplitude % 10);
-
- } // END if
-
- } // END while
-
- // Let the user know we are done with this mode.
- fprintf (PC_HOST, "Exit diagnostic mode.\n\r");
-
- return;
-}
-
-/** @} */
-
-
-/**
- * @defgroup DDS AD9954 DDS (Direct Digital Synthesizer)
- *
- * Functions to control the Analog Devices AD9954 DDS.
- *
- * @{
- */
-
-/// AD9954 CFR1 - Control functions including RAM, profiles, OSK, sync, sweep, SPI, and power control settings.
-#define DDS_AD9954_CFR1 0x00
-
-/// AD9954 CFR2 - Control functions including sync, PLL multiplier, VCO range, and charge pump current.
-#define DDS_AD9954_CFR2 0x01
-
-/// AD9954 ASF - Auto ramp rate speed control and output scale factor (0x0000 to 0x3fff).
-#define DDS_AD9954_ASF 0x02
-
-/// AD9954 ARR - Amplitude ramp rate for OSK function.
-#define DDS_AD9954_ARR 0x03
-
-/// AD9954 FTW0 - Frequency tuning word 0.
-#define DDS_AD9954_FTW0 0x04
-
-/// AD9954 FTW1 - Frequency tuning word 1
-#define DDS_AD9954_FTW1 0x06
-
-/// AD9954 NLSCW - Negative Linear Sweep Control Word used for spectral shaping in FSK mode
-#define DDS_AD9954_NLSCW 0x07
-
-/// AD9954 PLSCW - Positive Linear Sweep Control Word used for spectral shaping in FSK mode
-#define DDS_AD9954_PLSCW 0x08
-
-/// AD9954 RSCW0 - RAM Segment Control Word 0
-#define DDS_AD9954_RWCW0 0x07
-
-/// AD9954 RSCW0 - RAM Segment Control Word 1
-#define DDS_AD9954_RWCW1 0x08
-
-/// AD9954 RAM segment
-#define DDS_RAM 0x0b
-
-/// Current operational mode.
-DDS_MODE ddsMode;
-
-/// 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
-};
-
-/**
- * Initialize the DDS regsiters and RAM.
- */
-void ddsInit()
-{
- // Setup the SPI port for the DDS interface.
- setup_spi( SPI_MASTER | SPI_L_TO_H | SPI_CLK_DIV_4 | SPI_XMIT_L_TO_H );
-
- // Set the initial DDS mode. The ddsSetMode function uses this value to make the desired DDS selections.
- ddsMode = DDS_MODE_NOT_INITIALIZED;
-
- // Set the DDS operational mode.
- ddsSetMode (DDS_MODE_POWERDOWN);
-
- // Set the output to full scale.
- ddsSetOutputScale (0x3fff);
-
- // CFR2 (Control Function Register No. 2)
- output_low (IO_CS);
- spi_write (DDS_AD9954_CFR2);
-
- spi_write (0x00); // Unused register bits
- spi_write (0x00);
- spi_write (0x9c); // 19x reference clock multipler, high VCO range, nominal charge pump current
- output_high (IO_CS);
-
- // ARR (Amplitude Ramp Rate) to 15mS for OSK
- output_low (IO_CS);
- spi_write (DDS_AD9954_ARR);
-
- spi_write (83);
- output_high (IO_CS);
-
- // Strobe the part so we apply the updates.
- output_high (IO_UPDATE);
- output_low (IO_UPDATE);
-}
-
-/**
- * Set DDS amplitude value in the range 0 to 16383 where 16383 is full scale. This value is a
- * linear multiplier and needs to be scale for RF output power in log scale.
- *
- * @param scale in the range 0 to 16383
- */
-void ddsSetOutputScale (uint16_t scale)
-{
- // Set ASF (Amplitude Scale Factor)
- output_low (IO_CS);
- spi_write (DDS_AD9954_ASF);
-
- spi_write ((scale >> 8) & 0xff);
- spi_write (scale & 0xff);
-
- output_high (IO_CS);
-
- // Strobe the DDS to set the amplitude.
- output_high (IO_UPDATE);
- output_low (IO_UPDATE);
-}
-
-/**
- * Set the DDS amplitude in units of dBc of full scale where 1 is 0.1 dB. For example, a value of 30 is 3dBc
- * or a value of 85 is 8.5dBc.
- *
- * @param amplitude in 0.1 dBc of full scale
- */
-void ddsSetAmplitude (uint8_t amplitude)
-{
- // Range limit based on the lookup table size.
- if (amplitude > 200)
- return;
-
- // Set the linear DDS ASF (Amplitude Scale Factor) based on the dB lookup table.
- ddsSetOutputScale (DDS_AMP_TO_SCALE[amplitude / 5]);
-
- // Toggle the DDS output low and then high to force it to ramp to the new output level setting.
- output_low (IO_OSK);
- delay_ms(25);
-
- output_high (IO_OSK);
- delay_ms(25);
-}
-
-/**
- * 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)
-{
- // Set FTW0 (Frequency Tuning Word 0)
- output_low (IO_CS);
- spi_write (DDS_AD9954_FTW0);
-
- spi_write ((ftw >> 24) & 0xff);
- spi_write ((ftw >> 16) & 0xff);
- spi_write ((ftw >> 8) & 0xff);
- spi_write (ftw & 0xff);
-
- output_high (IO_CS);
-
- // Strobe the DDS to set the frequency.
- output_high (IO_UPDATE);
- output_low (IO_UPDATE);
-}
-
-/**
- * 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)
-{
- // Set FTW0 (Frequency Tuning Word 0)
- output_low (IO_CS);
- spi_write (DDS_AD9954_FTW0);
-
- spi_write ((ftw0 >> 24) & 0xff);
- spi_write ((ftw0 >> 16) & 0xff);
- spi_write ((ftw0 >> 8) & 0xff);
- spi_write (ftw0 & 0xff);
-
- output_high (IO_CS);
-
- // Set FTW0 (Frequency Tuning Word 1)
- output_low (IO_CS);
- spi_write (DDS_AD9954_FTW1);
-
- spi_write ((ftw1 >> 24) & 0xff);
- spi_write ((ftw1 >> 16) & 0xff);
- spi_write ((ftw1 >> 8) & 0xff);
- spi_write (ftw1 & 0xff);
-
- output_high (IO_CS);
-
- // Strobe the DDS to set the frequency.
- output_high (IO_UPDATE);
- output_low (IO_UPDATE);
-}
-
-/**
- * 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)
-{
- // Save the current mode.
- ddsMode = mode;
-
- switch (mode)
- {
- case DDS_MODE_POWERDOWN:
- // CFR1 (Control Function Register No. 1)
- output_low (IO_CS);
- spi_write (DDS_AD9954_CFR1);
-
- spi_write (0x00);
- spi_write (0x00);
- spi_write (0x00);
- spi_write (0xf0); // Power down all subsystems.
- output_high (IO_CS);
- break;
-
- case DDS_MODE_AFSK:
- // CFR1 (Control Function Register No. 1)
- output_low (IO_CS);
- spi_write (DDS_AD9954_CFR1);
-
- spi_write (0x03); // OSK Enable and Auto OSK keying
- spi_write (0x00);
- spi_write (0x00);
- spi_write (0x40); // Power down comparator circuit
- output_high (IO_CS);
- break;
-
- case DDS_MODE_FSK:
- // CFR1 (Control Function Register No. 1)
- output_low (IO_CS);
- spi_write (DDS_AD9954_CFR1);
-
- spi_write (0x03); // Clear RAM Enable, OSK Enable, Auto OSK keying
- spi_write (0x00);
- spi_write (0x00);
- spi_write (0x40); // Power down comparator circuit
- output_high (IO_CS);
-
- // NOTE: The sweep rate requires 1/4 of a bit time (26uS) to transition.
- // 6KHz delta = 70641 counts = (6KHz / 364.8MHz) * 2 ^ 32
- // SYNC_CLK = 91.2MHz 1/91.2MHz * 70641 * 1/29 = 26.7uS
-
- // NLSCW (Negative Linear Sweep Control Word)
- output_low (IO_CS);
- spi_write (DDS_AD9954_NLSCW);
-
- spi_write (1); // Falling sweep ramp rate word
- spi_write (0x00); // Delta frequency tuning word
- spi_write (0x00);
- spi_write (0x00);
- spi_write (250);
- output_high (IO_CS);
-
- // PLSCW (Positive Linear Sweep Control Word)
- output_low (IO_CS);
- spi_write (DDS_AD9954_PLSCW);
-
- spi_write (1); // Rising sweep ramp rate word
- spi_write (0x00); // Delta frequency tuning word
- spi_write (0x00);
- spi_write (0x00);
- spi_write (250);
- output_high (IO_CS);
- break;
- } // END switch
-
- // Strobe the DDS to change the mode.
- output_high (IO_UPDATE);
- output_low (IO_UPDATE);
-}
-
-/** @} */
-
-/**
- * @defgroup flash Flash Manager
- *
- * Functions to control the ST MP25P80 serial flash device.
- *
- * @{
- */
-
-/// Flash Chip Select - Port B3
-#define FLASH_CS PIN_B3
-
-/// Flash Clock - Port B5
-#define FLASH_CLK PIN_B5
-
-/// Flash Data Input - Port B4
-#define FLASH_D PIN_B4
-
-/// Flash Data Output - Port B2
-#define FLASH_Q PIN_B2
-
-/**
- * Determine if a flash write or erase operation is currently in progress.
- *
- * @return true if write/erase in progress
- */
-bool_t flashIsWriteInProgress()
-{
- uint8_t status;
-
- output_low (FLASH_CS);
-
- // Read Status Register (RDSR) flash command.
- flashSendByte (0x05);
-
- status = flashGetByte();
-
- output_high (FLASH_CS);
-
- return (((status & 0x01) == 0x01) ? true : false);
-}
-
-/**
- * Read a block of memory from the flash device.
- *
- * @param address of desired location in the range 0x00000 to 0xFFFFF (1MB)
- * @param block pointer to locate of data block
- * @param length number of bytes to read
- */
-void flashReadBlock(uint32_t address, uint8_t *block, uint16_t length)
-{
- uint16_t i;
-
- output_low (FLASH_CS);
-
- // Read Data Byte(s) (READ) flash command.
- flashSendByte (0x03);
- flashSendAddress (address);
-
- for (i = 0; i < length; ++i)
- *block++ = flashGetByte();
-
- output_high (FLASH_CS);
-}
-
-/**
- * Write a block of memory to the flash device.
- *
- * @param address of desired location in the range 0x00000 to 0xFFFFF (1MB)
- * @param block pointer data block to write
- * @param length number of bytes to write
- */
-void flashWriteBlock(uint32_t address, uint8_t *block, uint8_t length)
-{
- uint8_t i;
-
- output_low (FLASH_CS);
- // Write Enable (WREN) flash command.
- flashSendByte (0x06);
- output_high (FLASH_CS);
-
- output_low (FLASH_CS);
- // Page Program (PP) flash command.
- flashSendByte (0x02);
- flashSendAddress (address);
-
- for (i = 0; i < length; ++i)
- {
- // Send each byte in the data block.
- flashSendByte (*block++);
-
- // Track the address in the flash device.
- ++address;
-
- // If we cross a page boundary (a page is 256 bytes) we need to stop and send the address again.
- if ((address & 0xff) == 0x00)
- {
- output_high (FLASH_CS);
-
- // Write this block of data.
- while (flashIsWriteInProgress());
-
- output_low (FLASH_CS);
- // Write Enable (WREN) flash command.
- flashSendByte (0x06);
- output_high (FLASH_CS);
-
- output_low (FLASH_CS);
- // Page Program (PP) flash command.
- flashSendByte (0x02);
- flashSendAddress (address);
- } // END if
- } // END for
-
- output_high (FLASH_CS);
-
- // Wait for the final write operation to complete.
- while (flashIsWriteInProgress());
-}
-
-/**
- * Erase the entire flash device (all locations set to 0xff).
- */
-void flashErase()
-{
- output_low (FLASH_CS);
- // Write Enable (WREN) flash command.
- flashSendByte (0x06);
- output_high (FLASH_CS);
-
- output_low (FLASH_CS);
- // Bulk Erase (BE) flash command.
- flashSendByte (0xc7);
- output_high (FLASH_CS);
-
- while (flashIsWriteInProgress());
-}
-
-/**
- * Read a single byte from the flash device through the serial interface. This function
- * only controls the clock line. The chip select must be configured before calling
- * this function.
- *
- * @return byte read from device
- */
-uint8_t flashGetByte()
-{
- uint8_t i, value;
-
- value = 0;
-
- // Bit bang the 8-bits.
- for (i = 0; i < 8; ++i)
- {
- // Data is ready on the rising edge of the clock.
- output_high (FLASH_CLK);
-
- // MSB is first, so shift left.
- value = value << 1;
-
- if (input (FLASH_Q))
- value = value | 0x01;
-
- output_low (FLASH_CLK);
- } // END for
-
- return value;
-}
-
-/**
- * Initialize the flash memory subsystem.
- */
-void flashInit()
-{
- // I/O lines to control flash.
- output_high (FLASH_CS);
- output_low (FLASH_CLK);
- output_low (FLASH_D);
-}
-
-/**
- * Write a single byte to the flash device through the serial interface. This function
- * only controls the clock line. The chip select must be configured before calling
- * this function.
- *
- * @param value byte to write to device
- */
-void flashSendByte(uint8_t value)
-{
- uint8_t i;
-
- // Bit bang the 8-bits.
- for (i = 0; i < 8; ++i)
- {
- // Drive the data input pin.
- if ((value & 0x80) == 0x80)
- output_high (FLASH_D);
- else
- output_low (FLASH_D);
-
- // MSB is first, so shift leeft.
- value = value << 1;
-
- // Data is accepted on the rising edge of the clock.
- output_high (FLASH_CLK);
- output_low (FLASH_CLK);
- } // END for
-}
-
-/**
- * Write the 24-bit address to the flash device through the serial interface. This function
- * only controls the clock line. The chip select must be configured before calling
- * this function.
- *
- * @param address 24-bit flash device address
- */
-void flashSendAddress(uint32_t address)
-{
- uint8_t i;
-
- // Bit bang the 24-bits.
- for (i = 0; i < 24; ++i)
- {
- // Drive the data input pin.
- if ((address & 0x800000) == 0x800000)
- output_high (FLASH_D);
- else
- output_low (FLASH_D);
-
- // MSB is first, so shift left.
- address = address << 1;
-
- // Data is accepted on the rising edge of the clock.
- output_high (FLASH_CLK);
- output_low (FLASH_CLK);
- } // END for
-}
-
-/** @} */
-
-/**
- * @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.
-enum GPS_PARSE_STATE_MACHINE
-{
- /// 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
-};
-
-/// 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()
-{
- 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);
-
- // Enable the UART and the transmit line.
-#asm
- bsf 0xFAB.7
-#endasm
-}
-
-/**
- * Turn off the GPS engine power and serial interface.
- */
-void gpsPowerOff()
-{
- // Disable the UART and the transmit line.
-#asm
- bcf 0xFAB.7
-#endasm
-
- // 3.0 VDC LDO control line.
- output_low (IO_GPS_PWR);
-}
-
-/**
- * Read the serial FIFO and process complete GPS messages.
- */
-void gpsUpdate()
-{
- uint8_t value;
-
- // This state machine handles each characters as it is read from the GPS serial port.
- // We are looking for the GPS mesage @@Hb ... C
- while (serialHasData())
- {
- // Get the character value.
- value = serialRead();
-
- // Process based on the state machine.
- switch (gpsParseState)
- {
- case GPS_START1:
- if (value == '@')
- gpsParseState = GPS_START2;
- break;
-
- case GPS_START2:
- if (value == '@')
- gpsParseState = GPS_COMMAND1;
- else
- gpsParseState = GPS_START1;
- break;
-
- case GPS_COMMAND1:
- if (value == 'H')
- gpsParseState = GPS_COMMAND2;
- else
- gpsParseState = GPS_START1;
- break;
-
- case GPS_COMMAND2:
- if (value == 'b')
- {
- gpsParseState = GPS_READMESSAGE;
- gpsIndex = 0;
- gpsChecksum = 0;
- gpsChecksum ^= 'H';
- gpsChecksum ^= 'b';
- } else
- gpsParseState = GPS_START1;
- break;
-
- case GPS_READMESSAGE:
- gpsChecksum ^= value;
- gpsBuffer[gpsIndex++] = value;
-
- if (gpsIndex == 47)
- gpsParseState = GPS_CHECKSUMMESSAGE;
-
- break;
-
- case GPS_CHECKSUMMESSAGE:
- if (gpsChecksum == value)
- gpsParseState = GPS_EOMCR;
- else
- gpsParseState = GPS_START1;
- break;
-
- case GPS_EOMCR:
- if (value == 13)
- gpsParseState = GPS_EOMLF;
- else
- gpsParseState = GPS_START1;
- break;
-
- case GPS_EOMLF:
- // Once we have the last character, convert the binary message to something usable.
- if (value == 10)
- gpsParsePositionMessage();
-
- gpsParseState = GPS_START1;
- break;
- } // END switch
- } // END while
-}
-
-/** @} */
-
-
-/**
- * @defgroup log Flight Data Recorder
- *
- * Functions to manage and control the flight data recorder
- *
- * @{
- */
-
-/// Number of bytes to buffer before writing to flash memory.
-#define LOG_WRITE_BUFFER_SIZE 40
-
-/// Last used address in flash memory.
-uint32_t logAddress;
-
-/// Temporary buffer that holds data before it is written to flash device.
-uint8_t logBuffer[LOG_WRITE_BUFFER_SIZE];
-
-/// Current index into log buffer.
-uint8_t logIndex;
-
-/**
- * Last used address in flash memory. This location is where the next log data will
- * be written.
- *
- * @return 24-bit flash memory address
- */
-uint32_t logGetAddress()
-{
- return logAddress;
-}
-
-/**
- * Write the contents of the temporary log buffer to the flash device. If the buffer
- * is empty, nothing is done.
- */
-void logFlush()
-{
- // We only need to write if there is data.
- if (logIndex != 0)
- {
- flashWriteBlock (logAddress, logBuffer, logIndex);
- logAddress += logIndex;
- logIndex = 0;
- } // END if
-}
-
-/**
- * Prepare the flight data recorder for logging.
- */
-void logInit()
-{
- uint8_t buffer[8];
- bool_t endFound;
-
- fprintf (PC_HOST, "Searching for end of flash log...");
-
- logAddress = 0x0000;
- endFound = false;
-
- // Read each logged data block from flash to determine how long it is.
- do
- {
- // Read the data log entry type.
- flashReadBlock (logAddress, buffer, 1);
-
- // Based on the log entry type, we'll skip over the data contained in the entry.
- switch (buffer[0])
- {
- case LOG_BOOTED:
- logAddress += 7;
- break;
-
- case LOG_COORD:
- logAddress += 26;
- break;
-
- case LOG_TEMPERATURE:
- logAddress += 3;
- break;
-
- case LOG_VOLTAGE:
- logAddress += 5;
- break;
-
- case 0xff:
- endFound = true;
- break;
-
- default:
- ++logAddress;
- } // END switch
- } while (logAddress < 0x100000 && !endFound);
-
- fprintf (PC_HOST, "done. Log contains %ld bytes.\n\r", logAddress);
-
- logIndex = 0;
-}
-
-/**
- * Start a entry in the data log.
- *
- * @param type of log entry, i.e. LOG_BOOTED, LOG_COORD, etc.
- */
-void logType (LOG_TYPE type)
-{
- // Only add the new entry if there is space.
- if (logAddress >= 0x100000)
- return;
-
- // Write the old entry first.
- logFlush();
-
- // Save the type and set the log buffer pointer.
- logBuffer[0] = type;
- logIndex = 1;
-}
-
-/**
- * Save an unsigned, 8-bit value in the log.
- *
- * @param value unsigned, 8-bit value
- */
-void logUint8 (uint8_t value)
-{
- logBuffer[logIndex++] = value;
-}
-
-/**
- * Save a signed, 16-bit value in the log.
- *
- * @param value signed, 16-bit value
- */
-void logInt16 (int16_t value)
-{
- logBuffer[logIndex++] = (value >> 8) & 0xff;
- logBuffer[logIndex++] = value & 0xff;
-}
-
-/**
- * Save an unsigned, 16-bit value in the log.
- *
- * @param value unsigned, 16-bit value
- */
-void logUint16 (uint16_t value)
-{
- logBuffer[logIndex++] = (value >> 8) & 0xff;
- logBuffer[logIndex++] = value & 0xff;
-}
-
-/**
- * Save a signed, 32-bit value in the log.
- *
- * @param value signed, 32-bit value
- */
-void logInt32 (int32_t value)
-{
- logBuffer[logIndex++] = (value >> 24) & 0xff;
- logBuffer[logIndex++] = (value >> 16) & 0xff;
- logBuffer[logIndex++] = (value >> 8) & 0xff;
- logBuffer[logIndex++] = value & 0xff;
-}
-
-/** @} */
-
-/**
- * @defgroup LM92 LM92 temperature sensor
- *
- * Read and control the National Semiconductor LM92 I2C temperature sensor
- *
- * @{
- */
-
-/**
- * Read the LM92 temperature value in 0.1 degrees F.
- *
- * @return 0.1 degrees F
- */
-int16_t lm92GetTemp()
-{
- int16_t value;
- int32_t temp;
-
- // Set the SDA and SCL to input pins to control the LM92.
- set_tris_c (0x9a);
-
- // Read the temperature register value.
- i2c_start();
- i2c_write(0x97);
- value = ((int16_t) i2c_read() << 8);
- value = value | ((int16_t) i2c_read() & 0x00f8);
- i2c_stop();
-
- // Set the SDA and SCL back to outputs for use with the AD9954 because we share common clock pins.
- set_tris_c (0x82);
-
- // LM92 register 0.0625degC/bit 9 10 9
- // ------------- * -------------- * - * -- = -- + 320
- // 8 5 64
-
- // Convert to degrees F.
- temp = (int32_t) value;
- temp = ((temp * 9l) / 64l) + 320;
-
- return (int16_t) temp;
-}
-
-/** @} */
-
-
-/**
- * @defgroup serial Serial Port FIFO
- *
- * FIFO for the built-in serial port.
- *
- * @{
- */
-
-/// Size of serial port FIFO in bytes. It must be a power of 2, i.e. 2, 4, 8, 16, etc.
-#define SERIAL_BUFFER_SIZE 64
-
-/// Mask to wrap around at end of circular buffer. (SERIAL_BUFFER_SIZE - 1)
-#define SERIAL_BUFFER_MASK 0x3f
-
-/// Index to the next free location in the buffer.
-uint8_t serialHead;
-
-/// Index to the next oldest data in the buffer.
-uint8_t serialTail;
-
-/// Circular buffer (FIFO) to hold serial data.
-uint8_t serialBuffer[SERIAL_BUFFER_SIZE];
-
-/**
- * Determine if the FIFO contains data.
- *
- * @return true if data present; otherwise false
- */
-bool_t serialHasData()
-{
- if (serialHead == serialTail)
- return false;
-
- return true;
-}
-
-/**
- * Initialize the serial processor.
- */
-void serialInit()
-{
- serialHead = 0;
- serialTail = 0;
-}
-
-/**
- * Get the oldest character from the FIFO.
- *
- * @return oldest character; 0 if FIFO is empty
- */
-uint8_t serialRead()
-{
- uint8_t value;
-
- // Make sure we have something to return.
- if (serialHead == serialTail)
- return 0;
-
- // Save the value.
- value = serialBuffer[serialTail];
-
- // Update the pointer.
- serialTail = (serialTail + 1) & SERIAL_BUFFER_MASK;
-
- return value;
-}
-
-/**
- * Read and store any characters in the PIC serial port in a FIFO.
- */
-void serialUpdate()
-{
- // If there isn't a character in the PIC buffer, just leave.
- while (kbhit())
- {
- // Save the value in the FIFO.
- serialBuffer[serialHead] = getc();
-
- // Move the pointer to the next open space.
- serialHead = (serialHead + 1) & SERIAL_BUFFER_MASK;
- }
-}
-
-/** @} */
-
-/**
- * @defgroup sys System Library Functions
- *
- * Generic system functions similiar to the run-time C library.
- *
- * @{
- */
-
-/**
- * Calculate the CRC-16 CCITT of buffer that is length bytes long.
- * The crc parameter allow the calculation on the CRC on multiple buffers.
- *
- * @param buffer Pointer to data buffer.
- * @param length number of bytes in data buffer
- * @param crc starting value
- *
- * @return CRC-16 of buffer[0 .. length]
- */
-uint16_t sysCRC16(uint8_t *buffer, uint8_t length, uint16_t crc)
-{
- uint8_t i, bit, value;
-
- for (i = 0; i < length; ++i)
- {
- value = buffer[i];
-
- for (bit = 0; bit < 8; ++bit)