I'm working with 2 XBEEs : one master and one slave.
Master send a frame which is read by slave.
With the master, i send a frame with XCTU.
This frame construction is detailed in attachments : "Frame_XCTU".
In this frame i send, there is a "Strt" which has to be detected by the other XBEE module (slave).
I store all the frame received in a String and then search for "Strt" with the indexOf function.
When I print the frame received, i see that "Strt" is read. But the result of indexOf is "-1", so it can't find the word in the frame received ...
You can also find the printed results in attachment : "Serial_Results".
Could it be linked to the format of the frame ?
I feel like it could be due to the "RF Data" part in my frame construction ... (cf Frame_XCTU)
Here is my code :
#include <SoftwareSerial.h>
#define RXPIN 0 // Arduino Pin for Reception
#define TXPIN 1 // Arduino Pin for Transmission
SoftwareSerial xbee(RXPIN,TXPIN); // link virtual serial between xbee and arduino
/* Communication */
int i,found ;
String frame = ""; //sent to the other XBEE
String state_start=""; //for start
String received=""; //received from the other XBEE
char c; //byte received
void setup() {
Serial.begin(9600); //opening serial with 9600 baud
/* XBee Initialisation */
while(!Serial)
{ ; } //waiting for Serial Port
xbee.begin(9600); // opening serial xbee with 9600 baud
Serial.println("Arduino is ready"); //serial link activated
}
void loop() {
//Waiting for the Start of Pi
if(state_start=="Strt"){
Serial.println("Start received ! ");
Serial.println("Data ready to be sent !");
}
else {
state_start="";
received="";
xbee.flush(); //clear out
c=xbee.read();
//Start Delimiter Detected
if (c==0x7E) {
received.concat(c);
for (i=0;i<16;i++) {
c=xbee.read();
Serial.println(c);
Serial.println(c,HEX);
received.concat(c);
}
Serial.println(received);
found = received.indexOf("Strt"); //detect "Send" and return index
Serial.print("With indexOf : ");
Serial.println(found);
if (found != -1) {
state_start="Strt"; }
}
} }
#define RXPIN 0 // Arduino Pin for Reception
#define TXPIN 1 // Arduino Pin for Transmission
SoftwareSerial xbee(RXPIN,TXPIN); // link virtual serial between xbee and arduino
Pretty silly to be doing software serial on the hardware serial pins.
Serial.begin(9600); //opening serial with 9600 baud
Pretty stupid to think you can do it at the same time you are doing hardware serial on those pins.
xbee.flush(); //clear out
The flush() method blocks until the outgoing buffer is empty. How is THAT useful?
//Start Delimiter Detected
if (c==0x7E) {
received.concat(c);
for (i=0;i<16;i++) {
Just because the start delimiter has arrived does NOT mean that there are 16 more bytes in the buffer to be read.
You MUST make sure you actually read something USEFUL before adding it to the String.
found = received.indexOf("Strt"); //detect "Send" and return index
If SoftwareSerial isn't not ok for XBEE, shall i just use Serial ?
SoftwareSerial IS OK. You just can't do software serial on the same pins you are doing hardware serial on, any more than you can put two feet in one shoe.
I actually send 13 bytes.
Oh. Well, that explains why you think you can read 16 bytes, without ever checking that there IS anything to read.
Can Arrays be appropriated to store bytes from the frame ?
Apparently the problem came from the 0 (option field before my data) which is a delimiter of end chain. When using "indexOf" the function is searching characters before the 0.
So I split the entire frame stored in String in two parts.
The first 8 characters in one part and the rest in another part.
Then I apply the indexOf function on the second part and now i detect properly the word i wanna find.
