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TinyDuino Processors & TinyShields / unable to get a reading from the GPS TinyShield

« on: May 26, 2014, 05:36:55 PM »

Unable to get a reading from the GPS TinyShield. I've read the documentation for the GPS TinyShield as well as the notes from the TinyGPSPlus library. I have the TinyDuino board at the bottom, then the GPS TinyShield on top of the processor, and then the TinyShield USB & ICP board on top of the GPS.

I ran the Blink sketch successfully to ensure that everything was working properly. (From the IDE, the board I have selected is Arduino Pro or Pro Mini (3.3V, 8MHz) with ATmega328.)

To test the GPS, I used the setup from the example provided in the Tiny-Circuits site and then I used a simplified loop just to get some readings. However, I always seem to get the "No GPS detected" message. I also wasn't sure exactly which pin A0 or A1 is the RX pin on the GPS TinyShield - the example code has RX as A1 but the text above th example code on the Tiny-Circuits GPS tutorial states that RX is A0. I tried it both ways - same result.

I can't figure out why I am not getting any readings.

Code: [Select]

#include <TinyGPS++.h>
#include <SoftwareSerial.h>
/*
   This sample code demonstrates the normal use of a TinyGPS++ (TinyGPSPlus) object.
*/
static const int GPS_ONOFFPin = A3;
static const int GPS_SYSONPin = A2;
static const int GPS_RXPin = A0;
static const int GPS_TXPin = A1;
static const int GPSBaud = 9600;

// The TinyGPS++ object
TinyGPSPlus gps;

// The serial connection to the GPS device
SoftwareSerial ss(GPS_RXPin, GPS_TXPin);

void setup()
{
  Serial.begin(115200);
 
  // Init the GPS Module to wake mode
  pinMode(GPS_SYSONPin, INPUT);
  pinMode(GPS_ONOFFPin, OUTPUT);
  digitalWrite( GPS_ONOFFPin, LOW );   
  delay(5);
  if( digitalRead( GPS_SYSONPin ) == LOW )
  {
    // Need to wake the module
    digitalWrite( GPS_ONOFFPin, HIGH );
    delay(5);
    digitalWrite( GPS_ONOFFPin, LOW );     
  }

  ss.begin(GPSBaud);
}

void loop()
{
  while (ss.available())
    if (gps.encode(ss.read()))
    {
      Serial.print(F("Location: "));
      Serial.print(gps.location.lat(), 6);
      Serial.print(F(","));
      Serial.print(gps.location.lng(), 6);
    }
   
  if (millis() > 5000 && gps.charsProcessed() < 10)
  {
    Serial.println(F("No GPS detected: check wiring."));
    while(true);
  }
}