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1  Using Arduino / Project Guidance / Re: GPS, Serial LCD, and SD card... too much for the Uno's pins? on: March 27, 2014, 11:40:39 pm
I think you are probably running out of memory. I've tried a similar thing, running a GPS, SD card, and a 7-segment LED display. Any two would work. When I used all three it would behave strangely, rebooting itself sometimes. The problem was that the Arduino was running out of memory. I ended up re-writing the display and GPS libraries to cut out some of the features I didn't need. The SD library was more complicated so I didn't touch that.

Now I'm trying to build a similar project, using an Uno R3, GPS/SD logging shield from Adafruit, and a Nokia LCD display, and I'm running into the same problem. The Nokia LCD display doesn't have its own buffer so it all has to be buffered in the Arduino. At the moment I've not been able to get it trimmed down small enough. If anyone has a very light-weight SD library, that would be great.
2  Using Arduino / Project Guidance / Re: Ability to use TinyGPs and Arduino Mini Pro on: December 14, 2012, 11:48:15 pm
Then this should work...
except that it doesn't.
You know, I once had a college professor who repeated this mantra,

"it's in the wiring"

without even looking at your problem specifically, and he was always right.

 smiley-red
3  Using Arduino / Project Guidance / Re: Ability to use TinyGPs and Arduino Mini Pro on: December 14, 2012, 05:15:19 pm
Then this should work...
Code:
void setup() {
  Serial.begin(57600);     // gps TX,RX on 0,1
}

void loop() {
  if (Serial.available()) {
    Serial.print(Serial.read());
  }
}
except that it doesn't. If I hold in the reset button -- so that presumably the microcontroller isn't doing anything -- then I see the NMEA messages come out. As soon as I release the reset button then nothing is printed anymore, except sometimes I see one more sentence.

However, the following code does work,

Code:
#include <SoftwareSerial.h>
SoftwareSerial gps(3, 2);   // gps TX,RX on 2,3

void setup() {
  Serial.begin(57600);      // serial monitor
  gps.begin(57600);         // serial to GPS
  }

void loop() {
  gps.listen();             // doesn't seem to matter if this is here or not
  if (gps.available()) Serial.print((char)gps.read());
  if (Serial.available()) gps.print((char)Serial.read());
  }
4  Using Arduino / Project Guidance / Re: Ability to use TinyGPs and Arduino Mini Pro on: December 14, 2012, 05:46:57 am
Can you use the hardware serial (on pins 0 and 1) for the GPS?

How does one do this? I have this same GPS unit. If I connect it to the hardware serial and then just upload a blank sketch and start the serial monitor then I see the GPS messages being spit out. I tried a sketch which opens the hardware serial, reads the GPS and writes it to an SD (without starting the serial monitor) and it doesn't seem to write any data.

There must be a way to read the GPS through the hardware serial (and then do something with this data) but I haven't figured it out yet. Seems like if I open the serial port [ I.E. Serial.begin(57600); ] then it connects to the host computer. And of course if I don't open the serial port then I don't see how I can get GPS data.

Thanks.
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