Splitting a string and assigning to fields

Projects Programming
1

Hi,

If I had a string like:

char payload[32] = "100 2 5 7";

How could I split it on the spaces and assign the numbers to variables like

Id = 100

temp = 2

humidity = 5 

direction = 7

Thanks

2

strtok for splitting character arrays

3

Or sprintf sscanf :wink:

Edit: often mixing sprintf and sscanf for some reason :confused:

4

Thought you were passing in a struct as your payload? Just cast the pointer of the first element to your struct type and it will fill in your variables for you.

5

Indeed strtok for splitting the arrays but that gives you new strings. To make them to int values use:

void setup(){
  char multiDecString[] = "100 2 5 7";
  
  int id = strToInt(strtok(multiDecString, " "));
  int temp = strToInt(strtok(NULL, " "));
  int humidity = strToInt(strtok(NULL, " "));
  int direction = strToInt(strtok(NULL, " "));
}

void loop(){
  
}

unsigned int strToInt(char *str){
  byte i = 0;
  unsigned int rtn = 0;
  while(str[i]){
    if(str[i] >= 0x30 && str[i] < (0x30 + 10)){
      rtn *= 10;
      rtn += (str[i] - 0x30);
      i++;
    }
    else{
      break;
    }
  }
  return rtn;
}
6

@septilion: is there something wrong with atoi ?

7

Nope, nothing wrong with that. But in my searches I only found stoi which isn't part of Arduino. atoi works the same as my code :stuck_out_tongue: It's indeed easier to use that. :smiley: Unless you would like to be able to pass binary or hex as well. Then my code is easy adaptable.

8

There is a parse example in serial input basics that shows how to convert strings to numbers

...R