Add Float to String Variable

Hello,
I'm going to move your question over to the CC3200 forum as I believe they will be able to help with your code question better than us in the temp sensor forum.

Hi User4298886,

user4298886 said:

//This doesnt String pubString = "Temperature " + long(diet); Serial.print(pubString);

Seems there is bug in energia. Please raise this issue in energia forum.

Meantime please try with below code snippet for string append :

String pubString = "Temperature ";

pubString  += long(diet);

Serial.print(pubString);

More details please refer following link http://energia.nu/Tutorial_StringAppendOperator.html

Regards,

Aashish

Hi Aashish,

Thanks for the reply. I've tried your code and the result is the same as the issues I'm seeing - it still strips the temperature value after the decimal point.

If I try the following, I get zeros again:

String pubString = "Temperature Test ";
  
pubString  += diet;

Serial.print(pubString);

I will raise this in the Energia forum too.

Thanks

Hi user4298886,


Do you mean it not printing decimal part eg rather than printing 40.05, it printing 40.


Regards,
Aashish

Hi Aashish,

That's exactly it, it is everything following the point - it will display 20, instead of 20.12, and using the other code, it will be just 0.00

Thanks

Hi user4298886,


That is expected as you typecasting float as long.


Regards,
Aashish

Hi,

Ok, How would it be possible to convert the full long value into a string variable or is this possible?

It is possible to print the long fine with Serial.print(long value).

Thanks

Hi user4298886,


You mean float. try following way:

char buffer[8];
sprintf(buffer, "%.2f", diet);
pubString = "Temperature ";
pubString += buffer;
Serial.println(pubString);


You will get on console like this "Temperature 40.50"

Note: Float concatenation using operator '+' and '+=' not supported as per cc3200\cores\cc3200\WString.h


Regards,
Aashish

Hi,

Thanks for the code.

Using this example, I now get 0.00:

"Temperature 0.00"

Thanks

Hi user4298886,


We suspecting diet value is 0 . To make sure code is ok can you try below thing

diet = 40.05;
sprintf(buffer, "%.2f", diet);
pubString = "Temperature ";
pubString += buffer;
Serial.println(pubString);


Regards,
Aashish

Hi Aashish,

Tried your code and still getting 0.00.

Here is the code I used - I had to change some of the variables as they exist already in my sketch.

String pubString7;
char buffer1[8];
float diet1 = 40.05;

sprintf(buffer1, "%.2f", diet1);
pubString7 = "Temperature Test : ";
pubString7 += buffer1;
Serial.println(pubString7);

Thanks

Michael

Hi Michael,

That's the strange. It should be print 0.00. For your reference attaching code (ConnectWithWPA.ino) that working at my side. I am getting following output on console. 

Temperature Test : 40.05

Regards,

Aashish

Hi Aashish,

Thanks again for the help on this one.

I am using the sketch which you sent over, but still seeing the zero values:

#ifndef __CC3200R1M1RGC__
// Do not include SPI for CC3200 LaunchPad
#include <SPI.h>
#endif

void setup() {
//Initialize serial and wait for port to open:
Serial.begin(115200);
}

void loop() {
String pubString7;
char buffer1[8];
float diet1 = 40.05;

sprintf(buffer1, "%.2f", diet1);
pubString7 = "Temperature Test : ";
pubString7 += buffer1;
Serial.println(pubString7);
delay(1000);
}

Temperature Test : 0.00
Temperature Test : 0.00
Temperature Test : 0.00
Temperature Test : 0.00
Temperature Test : 0.00
Temperature Test : 0.00

Thanks

Hi Michael,


I am getting same issue if spi.h not included (means if I comment #include<SPI.h>). So seems SPI.h not getting include or issue with energia setup. I am using Energia0101E0013 and CC3200 HZ device.


Regards,
Aashish

Hi Aashish,

Yep, I get the same results when I comment SPI out, and now the value is show correct.

Now on my original sketch, when I comment out SPI.h, it still shows zeros. Here is what I am including:

#ifndef __CC3200R1M1RGC__
//#include <SPI.h>
#endif
#include <WiFi.h>
#include <PubSubClient.h>
#include <math.h>
#include "Adafruit_TMP006.h"
#include <Wire.h>
#include <stdlib.h>

I am using the exact same code from above, but getting zeros.

Thanks

Michael

Hi Michael,

Donn't comment SPI.h. Also rather than creating new project export an cc3200 example and modify it as per your need and save as new project. As it seems when we create new project from scratch it not include required header file in compilation script. 

Regards,

Aashish

Hi Aashish,

Sorry I was not sure what you meant, but I have tried a few options, with and without SPI.h defined..

- Created new sketch where your example code works, added my code and it now shows zeros

- Opened up and example sketch, added your code - this works, then add my code and it goes to zeros

Thanks

Michael

Hi Michael,


That's very strange. Are you sure tmp006.readDieTempC() not returning 0.


Regards,
Aashish

Hi Michael,


Is this issue resolved ? If yes please close this thread.


Regards,
Aashish

Hi Aashish,

Thanks for bringing this back up, yes I am still seeing the issue.

tmp006.readDieTempC() is returning a value, the following confirms that:

Serial.print("Die Temperature: "); Serial.print(diet); Serial.println("*C");

It is very odd as to what is breaking this, as it works fine in a new sketch, but when I create a new one and add my code on top of it, it breaks it!

Thanks

Michael