Voting resources, early voting, and poll worker information - VOTE. ... Adafruit is open and shipping.
0

Adafruit GPS library: I2C_Parsing only works in main loop?
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

Adafruit GPS library: I2C_Parsing only works in main loop?

by SciWax on Sat Feb 29, 2020 6:44 am

Hello,

first thanks for the useful out of the box examples from your libraries. They always help me a lot, :)

I have the following issue. I've bought a Mini GPS PA1010D and want to use it to get the time via NMEA sentences and store the time in the sketch using the time library from Paul Stoffregen. First, I've wanted loop the example code in the setup till a certain condition is fullfilled, so I can set the right time before jumping into the loop. I've wanted to use a do-while loop for that, where the condition is, that the time was set (Set time is not 01.01.1970 anymore). The behaviour of the example code really confused me though. It always jumps out of the do-while loop with immediate effect, while the same code works in the main loop portion.

Later, I want to occasionally sync the time. I want to trigger measurements by sensors in the main loop and after a specific time intervall, I want to sync the time through the device, but I feel kinda restricted at the moment, when basing my idea on the example code. I think I'm just missing something.

Code: Select all | TOGGLE FULL SIZE
// Test code for Adafruit GPS That Support Using I2C
//
// This code shows how to parse data from the I2C GPS
//
// Pick one up today at the Adafruit electronics shop
// and help support open source hardware & software! -ada

#include <Adafruit_GPS.h>

// Connect to the GPS on the hardware I2C port
Adafruit_GPS GPS(&Wire);

// Set GPSECHO to 'false' to turn off echoing the GPS data to the Serial console
// Set to 'true' if you want to debug and listen to the raw GPS sentences
#define GPSECHO false

uint32_t timer = millis();

void setup()
{
  //while (!Serial);  // uncomment to have the sketch wait until Serial is ready

  // connect at 115200 so we can read the GPS fast enough and echo without dropping chars
  // also spit it out
  Serial.begin(9600);
  Serial.println("Adafruit I2C GPS library basic test!");

  // 9600 NMEA is the default baud rate for Adafruit MTK GPS's- some use 4800
  GPS.begin(0x10);  // The I2C address to use is 0x10
  // uncomment this line to turn on RMC (recommended minimum) and GGA (fix data) including altitude
  GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCGGA);
  // uncomment this line to turn on only the "minimum recommended" data
  //GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCONLY);
  // For parsing data, we don't suggest using anything but either RMC only or RMC+GGA since
  // the parser doesn't care about other sentences at this time
  // Set the update rate
  GPS.sendCommand(PMTK_SET_NMEA_UPDATE_1HZ); // 1 Hz update rate
  // For the parsing code to work nicely and have time to sort thru the data, and
  // print it out we don't suggest using anything higher than 1 Hz

  // Request updates on antenna status, comment out to keep quiet
  GPS.sendCommand(PGCMD_ANTENNA);

  delay(1000);

  // Ask for firmware version
  GPS.println(PMTK_Q_RELEASE);


delay(10000);
int k = 100;
 do {Serial.println("Testing do-while loop in setup.....");
 k++;
} while (k < 1000);

delay(10000);

int i = 0;
  do {  i++;
  // read data from the GPS in the 'main loop'
  char c = GPS.read();
  // if you want to debug, this is a good time to do it!
  if (GPSECHO)
    if (c) Serial.print(c);
  // if a sentence is received, we can check the checksum, parse it...
  if (GPS.newNMEAreceived()) {
    // a tricky thing here is if we print the NMEA sentence, or data
    // we end up not listening and catching other sentences!
    // so be very wary if using OUTPUT_ALLDATA and trying to print out data
    Serial.println(GPS.lastNMEA()); // this also sets the newNMEAreceived() flag to false
    if (!GPS.parse(GPS.lastNMEA())) // this also sets the newNMEAreceived() flag to false
      return; // we can fail to parse a sentence in which case we should just wait for another
  }

  // approximately every 2 seconds or so, print out the current stats
  if (millis() - timer > 2000) {
    timer = millis(); // reset the timer
    Serial.print("\nTime: ");
    if (GPS.hour < 10) { Serial.print('0'); }
    Serial.print(GPS.hour, DEC); Serial.print(':');
    if (GPS.minute < 10) { Serial.print('0'); }
    Serial.print(GPS.minute, DEC); Serial.print(':');
    if (GPS.seconds < 10) { Serial.print('0'); }
    Serial.print(GPS.seconds, DEC); Serial.print('.');
    if (GPS.milliseconds < 10) {
      Serial.print("00");
    } else if (GPS.milliseconds > 9 && GPS.milliseconds < 100) {
      Serial.print("0");
    }
    Serial.println(GPS.milliseconds);
    Serial.print("Date: ");
    Serial.print(GPS.day, DEC); Serial.print('/');
    Serial.print(GPS.month, DEC); Serial.print("/20");
    Serial.println(GPS.year, DEC);
    Serial.print("Fix: "); Serial.print((int)GPS.fix);
    Serial.print(" quality: "); Serial.println((int)GPS.fixquality);
    if (GPS.fix) {
      Serial.print("Location: ");
      Serial.print(GPS.latitude, 4); Serial.print(GPS.lat);
      Serial.print(", ");
      Serial.print(GPS.longitude, 4); Serial.println(GPS.lon);
      Serial.print("Speed (knots): "); Serial.println(GPS.speed);
      Serial.print("Angle: "); Serial.println(GPS.angle);
      Serial.print("Altitude: "); Serial.println(GPS.altitude);
      Serial.print("Satellites: "); Serial.println((int)GPS.satellites);
    }
  }
} while (i < 1000);

Serial.print("End of do-while loop examples in setup");

delay(20000);
 
}

void loop() // run over and over again
{ Serial.println("In void loop() the same code works...");

  // read data from the GPS in the 'main loop'
  char c = GPS.read();
  // if you want to debug, this is a good time to do it!
  if (GPSECHO)
    if (c) Serial.print(c);
  // if a sentence is received, we can check the checksum, parse it...
  if (GPS.newNMEAreceived()) {
    // a tricky thing here is if we print the NMEA sentence, or data
    // we end up not listening and catching other sentences!
    // so be very wary if using OUTPUT_ALLDATA and trying to print out data
    Serial.println(GPS.lastNMEA()); // this also sets the newNMEAreceived() flag to false
    if (!GPS.parse(GPS.lastNMEA())) // this also sets the newNMEAreceived() flag to false
      return; // we can fail to parse a sentence in which case we should just wait for another
  }

  // approximately every 2 seconds or so, print out the current stats
  if (millis() - timer > 2000) {
    timer = millis(); // reset the timer
    Serial.print("\nTime: ");
    if (GPS.hour < 10) { Serial.print('0'); }
    Serial.print(GPS.hour, DEC); Serial.print(':');
    if (GPS.minute < 10) { Serial.print('0'); }
    Serial.print(GPS.minute, DEC); Serial.print(':');
    if (GPS.seconds < 10) { Serial.print('0'); }
    Serial.print(GPS.seconds, DEC); Serial.print('.');
    if (GPS.milliseconds < 10) {
      Serial.print("00");
    } else if (GPS.milliseconds > 9 && GPS.milliseconds < 100) {
      Serial.print("0");
    }
    Serial.println(GPS.milliseconds);
    Serial.print("Date: ");
    Serial.print(GPS.day, DEC); Serial.print('/');
    Serial.print(GPS.month, DEC); Serial.print("/20");
    Serial.println(GPS.year, DEC);
    Serial.print("Fix: "); Serial.print((int)GPS.fix);
    Serial.print(" quality: "); Serial.println((int)GPS.fixquality);
    if (GPS.fix) {
      Serial.print("Location: ");
      Serial.print(GPS.latitude, 4); Serial.print(GPS.lat);
      Serial.print(", ");
      Serial.print(GPS.longitude, 4); Serial.println(GPS.lon);
      Serial.print("Speed (knots): "); Serial.println(GPS.speed);
      Serial.print("Angle: "); Serial.println(GPS.angle);
      Serial.print("Altitude: "); Serial.println(GPS.altitude);
      Serial.print("Satellites: "); Serial.println((int)GPS.satellites);
    }
  }
 
}
 


The jump from the Setup into the Main Loop happens with immediate effect. The last 2 lines in the Setup get completely ignored:

Code: Select all | TOGGLE FULL SIZE
Serial.print("End of do-while loop examples in setup");

delay(20000);


That's how the output looks:

Code: Select all | TOGGLE FULL SIZE
Testing do-while loop in setup.....
Testing do-while loop in setup.....
Testing do-while loop in setup.....

Time: 00:00:00.000
Date: 0/0/200
Fix: 0 quality: 0


In void loop() the same code works...
In void loop() the same code works...
In void loop() the same code works...
In void loop() the same code works...
In void loop() the same code works...


And in the Main Loop, the same code in the do-while loop from the Setup works. I would love some help, because I'm butting my head against this problem for more than a week now. I would love to get NMEA sentences and proper time through the GPS module using I2C in a non.blocking way,

Code: Select all | TOGGLE FULL SIZE
In void loop() the same code works...
In void loop() the same code works...
In void loop() the same code works...

Time: 10:52:03.17720
Date: 29/2/2020
Fix: 1 quality: 2
Location: deleted by me
Speed (knots): 0.48
Angle: 152.52
Altitude: 489.60
Satellites: 6
In void loop() the same code works...
In void loop() the same code works...

SciWax
 
Posts: 13
Joined: Tue Feb 25, 2020 5:26 am

Please be positive and constructive with your questions and comments.