How to print (or store) gps lat, lng value (TinyGPS++) with Bluetooth BLE nRF8001?

Question

I have a u-blox gps module and I use TinyGPS (http://arduiniana.org/libraries/tinygpsplus/) to get out the lat + lng.

If i write...

Serial.println(gps.location.lat(), 6); 

...out in the log I get the correct latvalue. Right now I however work with a BLE (https://www.adafruit.com/product/1697) and when I try to print it like this:

BTLEserial.print (gps.location.lat()`, 6); 

I get a error: no matching function for call to 'Adafruit_BLE_UART::print(double, int)'

If I do this instead, the code runs...

BTLEserial.print ((gps.location.lat(),6)); 

But I do not get the correct lat, instead I get this value 6.00000000

I have tried to store the lat like this:

double myLat;

myLat = (gps.location.lat(), 6);
BTLEserial.print (myLat);

But with that myLat also has a value of 6.00000000 which is not correct.

I tried this as well:

char sValueOne[16], sValueTwo[16];
char sBuffer[33];

strcpy(sBuffer,dtostrf(((gps.location.lat(),6)), 15, 8, sValueOne));
strcat(sBuffer,",");
strcat(sBuffer,dtostrf(((gps.location.lng(),6)), 15, 8, sValueTwo));

BTLEserial.write((uint8_t *)sBuffer, strlen(sBuffer));

But with that I still get 6.00000000. I am starting to run out of ideas now to make this work. I have tried to send it both directly and store it but nothing works successfully.

So how can I adjust the code to be able to print (or store) gps lat, lng value (TinyGPS++) with Bluetooth BLE nRF8001?

Appreciate every help and tips!

Answer 1

The Arduino Stream/Print classes may sometime need some extra attention.

BTLEserial.println(gps.location.lat()`, 6); 

The member function is available in the class Print but gets "hidden". You can help the compiler to find it with a prefix:

BTLEserial.Print::println(gps.location.lat()`, 6); 

Cheers!