Diff: MBed_Adafruit_GPS.cpp

Revision:

0:a23e3099bb0a

Child:

1:ff72e93bcb0e

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MBed_Adafruit_GPS.cpp	Sat Mar 22 05:00:47 2014 +0000
@@ -0,0 +1,350 @@
+/***********************************
+This is our GPS library
+
+Adafruit invests time and resources providing this open source code,
+please support Adafruit and open-source hardware by purchasing
+products from Adafruit!
+
+Written by Limor Fried/Ladyada for Adafruit Industries.
+BSD license, check license.txt for more information
+All text above must be included in any redistribution
+****************************************/
+
+#include "MBed_Adafruit_GPS.h"
+
+// how long are max NMEA lines to parse?
+#define MAXLINELENGTH 120
+
+// we double buffer: read one line in and leave one for the main program
+volatile char line1[MAXLINELENGTH];
+volatile char line2[MAXLINELENGTH];
+// our index into filling the current line
+volatile uint16_t lineidx=0;
+// pointers to the double buffers
+volatile char *currentline;
+volatile char *lastline;
+volatile bool recvdflag;
+volatile bool inStandbyMode;
+
+
+bool Adafruit_GPS::parse(char *nmea) {
+  // do checksum check
+
+  // first look if we even have one
+  if (nmea[strlen(nmea)-4] == '*') {
+    uint16_t sum = parseHex(nmea[strlen(nmea)-3]) * 16;
+    sum += parseHex(nmea[strlen(nmea)-2]);
+    
+    // check checksum 
+    for (uint8_t i=1; i < (strlen(nmea)-4); i++) {
+      sum ^= nmea[i];
+    }
+    if (sum != 0) {
+      // bad checksum :(
+      //return false;
+    }
+  }
+
+  // look for a few common sentences
+  if (strstr(nmea, "$GPGGA")) {
+    // found GGA
+    char *p = nmea;
+    // get time
+    p = strchr(p, ',')+1;
+    float timef = atof(p);
+    uint32_t time = timef;
+    hour = time / 10000;
+    minute = (time % 10000) / 100;
+    seconds = (time % 100);
+
+    milliseconds = fmod((double) timef, 1.0) * 1000;
+
+    // parse out latitude
+    p = strchr(p, ',')+1;
+    latitude = atof(p);
+
+    p = strchr(p, ',')+1;
+    if (p[0] == 'N') lat = 'N';
+    else if (p[0] == 'S') lat = 'S';
+    else if (p[0] == ',') lat = 0;
+    else return false;
+
+    // parse out longitude
+    p = strchr(p, ',')+1;
+    longitude = atof(p);
+
+    p = strchr(p, ',')+1;
+    if (p[0] == 'W') lon = 'W';
+    else if (p[0] == 'E') lon = 'E';
+    else if (p[0] == ',') lon = 0;
+    else return false;
+
+    p = strchr(p, ',')+1;
+    fixquality = atoi(p);
+
+    p = strchr(p, ',')+1;
+    satellites = atoi(p);
+
+    p = strchr(p, ',')+1;
+    HDOP = atof(p);
+
+    p = strchr(p, ',')+1;
+    altitude = atof(p);
+    p = strchr(p, ',')+1;
+    p = strchr(p, ',')+1;
+    geoidheight = atof(p);
+    return true;
+  }
+  if (strstr(nmea, "$GPRMC")) {
+   // found RMC
+    char *p = nmea;
+
+    // get time
+    p = strchr(p, ',')+1;
+    float timef = atof(p);
+    uint32_t time = timef;
+    hour = time / 10000;
+    minute = (time % 10000) / 100;
+    seconds = (time % 100);
+
+    milliseconds = fmod((double) timef, 1.0) * 1000;
+
+    p = strchr(p, ',')+1;
+    // Serial.println(p);
+    if (p[0] == 'A') 
+      fix = true;
+    else if (p[0] == 'V')
+      fix = false;
+    else
+      return false;
+
+    // parse out latitude
+    p = strchr(p, ',')+1;
+    latitude = atof(p);
+
+    p = strchr(p, ',')+1;
+    if (p[0] == 'N') lat = 'N';
+    else if (p[0] == 'S') lat = 'S';
+    else if (p[0] == ',') lat = 0;
+    else return false;
+
+    // parse out longitude
+    p = strchr(p, ',')+1;
+    longitude = atof(p);
+
+    p = strchr(p, ',')+1;
+    if (p[0] == 'W') lon = 'W';
+    else if (p[0] == 'E') lon = 'E';
+    else if (p[0] == ',') lon = 0;
+    else return false;
+
+    // speed
+    p = strchr(p, ',')+1;
+    speed = atof(p);
+
+    // angle
+    p = strchr(p, ',')+1;
+    angle = atof(p);
+
+    p = strchr(p, ',')+1;
+    uint32_t fulldate = atof(p);
+    day = fulldate / 10000;
+    month = (fulldate % 10000) / 100;
+    year = (fulldate % 100);
+
+    // we dont parse the remaining, yet!
+    return true;
+  }
+
+  return false;
+}
+
+char Adafruit_GPS::read(void) {
+  char c = 0;
+  
+  if (paused) return c;
+
+    if(!gpsSerial->readable()) return c;
+    c = gpsSerial->getc();
+
+  //Serial.print(c);
+
+  if (c == '$') {
+    currentline[lineidx] = 0;
+    lineidx = 0;
+  }
+  if (c == '\n') {
+    currentline[lineidx] = 0;
+
+    if (currentline == line1) {
+      currentline = line2;
+      lastline = line1;
+    } else {
+      currentline = line1;
+      lastline = line2;
+    }
+
+    lineidx = 0;
+    recvdflag = true;
+  }
+
+  currentline[lineidx++] = c;
+  if (lineidx >= MAXLINELENGTH)
+    lineidx = MAXLINELENGTH-1;
+
+  return c;
+}
+
+Adafruit_GPS::Adafruit_GPS (Serial *ser)
+{
+  common_init();     // Set everything to common state, then...
+  gpsSerial = ser; // ...override gpsSwSerial with value passed.
+}
+
+// Initialization code used by all constructor types
+void Adafruit_GPS::common_init(void) {
+  gpsSerial = NULL;
+  recvdflag   = false;
+  paused      = false;
+  lineidx     = 0;
+  currentline = line1;
+  lastline    = line2;
+
+  hour = minute = seconds = year = month = day =
+    fixquality = satellites = 0; // uint8_t
+  lat = lon = mag = 0; // char
+  fix = false; // bool
+  milliseconds = 0; // uint16_t
+  latitude = longitude = geoidheight = altitude =
+    speed = angle = magvariation = HDOP = 0.0; // float
+}
+
+void Adafruit_GPS::begin(int baud)
+{
+  gpsSerial->baud(baud);
+  wait_ms(10);
+}
+
+void Adafruit_GPS::sendCommand(char *str) {
+  gpsSerial->printf("%s",str);
+}
+
+bool Adafruit_GPS::newNMEAreceived(void) {
+  return recvdflag;
+}
+
+void Adafruit_GPS::pause(bool p) {
+  paused = p;
+}
+
+char *Adafruit_GPS::lastNMEA(void) {
+  recvdflag = false;
+  return (char *)lastline;
+}
+
+// read a Hex value and return the decimal equivalent
+uint8_t Adafruit_GPS::parseHex(char c) {
+    if (c < '0')
+      return 0;
+    if (c <= '9')
+      return c - '0';
+    if (c < 'A')
+       return 0;
+    if (c <= 'F')
+       return (c - 'A')+10;
+}
+
+bool Adafruit_GPS::waitForSentence(char *wait4me, uint8_t max) {
+  char str[20];
+
+  uint8_t i=0;
+  while (i < max) {
+    if (newNMEAreceived()) { 
+      char *nmea = lastNMEA();
+      strncpy(str, nmea, 20);
+      str[19] = 0;
+      i++;
+
+      if (strstr(str, wait4me))
+    return true;
+    }
+  }
+
+  return false;
+}
+
+bool Adafruit_GPS::LOCUS_StartLogger(void) {
+  sendCommand(PMTK_LOCUS_STARTLOG);
+  recvdflag = false;
+  return waitForSentence(PMTK_LOCUS_LOGSTARTED);
+}
+
+bool Adafruit_GPS::LOCUS_ReadStatus(void) {
+  sendCommand(PMTK_LOCUS_QUERY_STATUS);
+  
+  if (! waitForSentence("$PMTKLOG"))
+    return false;
+
+  char *response = lastNMEA();
+  uint16_t parsed[10];
+  uint8_t i;
+  
+  for (i=0; i<10; i++) parsed[i] = -1;
+  
+  response = strchr(response, ',');
+  for (i=0; i<10; i++) {
+    if (!response || (response[0] == 0) || (response[0] == '*')) 
+      break;
+    response++;
+    parsed[i]=0;
+    while ((response[0] != ',') && 
+       (response[0] != '*') && (response[0] != 0)) {
+      parsed[i] *= 10;
+      char c = response[0];
+      if (isdigit(c))
+        parsed[i] += c - '0';
+      else
+        parsed[i] = c;
+      response++;
+    }
+  }
+  LOCUS_serial = parsed[0];
+  LOCUS_type = parsed[1];
+  if (isalpha(parsed[2])) {
+    parsed[2] = parsed[2] - 'a' + 10; 
+  }
+  LOCUS_mode = parsed[2];
+  LOCUS_config = parsed[3];
+  LOCUS_interval = parsed[4];
+  LOCUS_distance = parsed[5];
+  LOCUS_speed = parsed[6];
+  LOCUS_status = !parsed[7];
+  LOCUS_records = parsed[8];
+  LOCUS_percent = parsed[9];
+
+  return true;
+}
+
+// Standby Mode Switches
+bool Adafruit_GPS::standby(void) {
+  if (inStandbyMode) {
+    return false;  // Returns false if already in standby mode, so that you do not wake it up by sending commands to GPS
+  }
+  else {
+    inStandbyMode = true;
+    sendCommand(PMTK_STANDBY);
+    //return waitForSentence(PMTK_STANDBY_SUCCESS);  // don't seem to be fast enough to catch the message, or something else just is not working
+    return true;
+  }
+}
+
+bool Adafruit_GPS::wakeup(void) {
+  if (inStandbyMode) {
+   inStandbyMode = false;
+    sendCommand("");  // send byte to wake it up
+    return waitForSentence(PMTK_AWAKE);
+  }
+  else {
+      return false;  // Returns false if not in standby mode, nothing to wakeup
+  }
+}
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