Thanks PaulS,
Firstly I must say I'm very unfamiliar with all this so not entirely sure what's going on here.
50000 is not a float. It is an integer (technically, a long int). Why do you want to convert it to a float?
Yes I realise that, the code I uploaded was just a test to see if I could get things to do what I wanted, what actually will happen is every reading I receive from my EC sensor will be three values comma separated giving me information on EC, total dissolved salts (TDS) and parts per million(PPM), these values wont necessarily be integers. I just want to try and split that string, take the first value and convert it into something (a float) I can use elsewhere in my code. The reason I used strtok_r instead of strtok came from this thread I read: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1231961642, I just changed it to strtok and got the following error:
function 'char* strtok(char*, const char*)'
sketch_apr21b:12: error: at this point in file