String of float variables.

Projects Programming
1

Hi All,

I have a program that collects data from a weather shield presents the data as floats and the logs the data to an sd card and exports to serial.

The program works but is there a better way to construct the string?
Also Is there a way to format the data with a leading zero ie the seconds go from 01, 02, 03... to 59.

As I said the code works but im am wondering if there is a cleaner way to do this.

Thanks in advanced for any help. :slight_smile:

void logWeather()
{
dtostrf(now.year(),4, 0,dtostrfbuffer);
  String dataA = (dtostrfbuffer);
  dtostrf(now.month(),2, 0,dtostrfbuffer);
  String dataB = (dtostrfbuffer);
  dtostrf(now.day(),2, 0,dtostrfbuffer);
  String dataC = (dtostrfbuffer);
  dtostrf(now.hour(),2, 0,dtostrfbuffer);
  String dataD = (dtostrfbuffer);
  dtostrf(now.minute(),2, 0,dtostrfbuffer);
  String dataE = (dtostrfbuffer);
  dtostrf(now.second(),2, 0,dtostrfbuffer);
  String dataF = (dtostrfbuffer);
  dtostrf(humidity,2, 2,dtostrfbuffer);
  String dataG = (dtostrfbuffer);
  dtostrf(tempf,2, 2,dtostrfbuffer);
  String dataH = (dtostrfbuffer);
  dtostrf(temp,2, 2,dtostrfbuffer);
  String dataI = (dtostrfbuffer);
  dtostrf(pressure,2, 2,dtostrfbuffer);
  String dataJ = (dtostrfbuffer);
  dtostrf(altitude,4, 2,dtostrfbuffer);
  String dataK = (dtostrfbuffer);
  dtostrf(altitudef,4, 2,dtostrfbuffer);
  String dataL = (dtostrfbuffer);
  dtostrf(light_lvl,2, 2,dtostrfbuffer);
  String dataM = (dtostrfbuffer);
  dtostrf(batt_lvl,2, 2,dtostrfbuffer);
  String dataN = (dtostrfbuffer);
  
    
   // make a string for assembling the data to log:
  String dataString = (dataA + ":" + dataB + ":" + dataC + ":" + dataD + ":" + dataE + ":" + dataF + ":" + dataG + ":" + dataH + ":" + dataI + ":" + dataJ + ":" + dataK + ":" + dataL + ":" + dataM + ":" + dataN);
  
  
  dataFile.println(dataString);
  Serial.println(dataString);

  dataFile.flush();
}
2

The program works but is there a better way to construct the string?

Are you asking about strings or the resource wasting Strings? Why do you need to have a string or String at all? Writing to the serial port is no more efficient with a string or String than writing the data directly. Ditto writing to an SD card.

3

Hi Thanks for the reply,

Im using the string format to send the group of information together. I did not think about sending the data items indavidually. I will take a look at this as an alternative.

My question was more about the if this is the correct way to do this as I am looking to improve my coding.

Presenting the data indavidually would give more control over the formatting issue I guess.

Thanks

4

My question was more about the if this is the correct way to do this as I am looking to improve my coding.

It's not, because what you are trying to do is not necessary.

5

Ok thanks.

I will investigate other options to simplify things.

Thanks for the help.