Hector Seguro's questions

I have that question of how it works ifin low level programming.

If so, it checks the RAM by going through all the addresses that contain it.

var ajax = $.ajax({
    method: "GET",
    url: "api/fichas",
    dataType: "json",
    success: function( strData ){
        alert("work");
        $("#agenda .content").append(strData);
    }
}).done(function(){
    console.log("WORK");
});

I have this code in a button, it makes the request but does not show anything, neither an error nor that it is already done (the .done() function)

    void loop() {
      String str = "F03A42";
      int start = 0;
      int arr[2][19];
      int t = 0;
      //El 'for' lo hace 6 veces hasta que acaba la cadena de datos
      for(int ends = 2;ends <= sizeof(str); ends += 2){
        char s[2];
        //Extra los 2 caracteres necesarios para la conversion
        str.substring(start, ends).toCharArray(s, sizeof(s) + 1);
        //Luego lo pasa a un array para luego procesarlo de otra manera
        //Aqui el problema, si hago:
        //arr[t] = (int)s & 0xFF; da un numero estatico (242)
        arr[t] = s; 
        start += 2;
        t++;
      }
   }

Example: F0 is written in hex (supposedly) but I need to pass that 2 char to a full-fledged byte.

void simplificado(){
    //El byte
    char bit[2] = 'F0';
    //Ejemplo
    byte d = CharToByte(bit);
    //Pero que si convierto 'd' se igual a 240 (Que es el numero entero de 0xF0)
}