Arduino: string to multiple variables - arrays

Question

I'm trying to send the data from two sensors through 433MHz radio communication. I have succeeded in sending and receiving the string(array of char) "number1,number2".
Now I'm trying to store both numbers in separate int variables (the values are over 256).
I've tried with almost everything (sscanf and atoi mainly), but it does not seem to work.
To A0 and A1 I have connected two potentiometers, whose values I want to store in valorX and valorY in the receiver arduino.
What do you suggest?
I cannot assure I used correctly sscanf and atoi.
Transmitter code:
#include <VirtualWire.h>
int xvalue;
int yvalue;
void setup() {
Serial.begin(9600);
vw_set_ptt_inverted(true); //
vw_set_tx_pin(12);
vw_setup(4000);// speed of data transfer Kbps
}
void loop() {
xvalue=analogRead(A0);
yvalue=analogRead(A1);
int envioX = map(xvalue, 0, 1023, 001, 1000); //I prefer to not send 0
int envioY = map(yvalue, 0, 1023, 001, 1000);
//Mando los datos del joystic
char envioXY[]="";
sprintf(envioXY,"%d,%d",envioX,envioY);
EnviarDatos(envioXY);
delay(1000);
}
void EnviarDatos(char datos[]){
vw_send((uint8_t *)datos, strlen(datos)); //vw_send(message, length)
vw_wait_tx(); // Wait until the whole message is gone
}
Receiver code:
#include <VirtualWire.h>
char recibo[8]="";
int valorX;
int valorY;
void setup(){
vw_set_ptt_inverted(true); // Required for DR3100
vw_set_rx_pin(12);
vw_setup(4000); // Bits per sec
vw_rx_start(); // Start the receiver PLL running
Serial.begin(9600);
Serial.println("setup");
}
void loop(){
uint8_t buf[VW_MAX_MESSAGE_LEN];
uint8_t buflen = VW_MAX_MESSAGE_LEN;
if (vw_get_message(buf, &buflen)){ //check to see if anything has been received
for(int i=0;i<buflen;i++){
recibo[i]=char(buf[i]);
Serial.print(recibo[i]);
}
recibo[buflen]=NULL;
//String str(recibo);
//What here to get both int??
}
}
What do you suggest?
I cannot assure I used correctly sscanf and atoi.
So the main question is how to convert "number1,number2" to int1=number1 and int2=number2.
Thanks and cheers
Gabriel

Answer 1

Transmitter code:
You must declare storage for the sprintf to use. You have only declared a 1-byte array which contains a NUL (0 byte) as the first and only element [0]:
char envioXY[]="";
Change it to this, which declares a character array with 24 elements:
char envioXY[ 24 ];
Although uninitialized, sprintf will set the array elements as it formats your 2 integers.
Receiver code:
After recibo[buflen] = NULL;, you can parse it with this:
sscanf( recibo, "%d,%d", &valorX, &valorY );
The format string matches the sprintf format, and the address of the two integers is passed in, not just the two integers.