Receive XBee signals on Arduino - serial-port

Question

Side A:
Arduino Uno R3 with Wireless Proto shield powered with USB
With XBee Pro S1, DH 0 DL FFFF MY 0 API 0
Wireless Proto shield has the serial select switch on the 'micro' position
side B:
XBee Explorer USB connected to a PC with XCTU software
With XBee Pro S1, DH 0 DL FFFF MY 0 API 0
(When I put both XBee modules in the USB explorer boards, connected with two PC's, I can send data back and forth without any problems, so I reckon the XBee settings are good.)
The Problem
Now I want the Arduino to capture the input from the B side (send with the XCTU terminal), but when I type anything in the terminal, the RSSI LED on side A just turns on for 5 seconds, but the Arduino does not seem to capture any data since it does not send data back like it should (Serial.print("I received: ");
Arduino sketch:
int incomingByte = 0;
void setup() {
Serial.begin(19200); //Both XBee chips are configured at 19200 Baud
Serial.print("start echo machine"); //This is received just fine on the B side
}
void loop() {
if (Serial.available() > 0) {
// Read the incoming byte:
incomingByte = Serial.read();
// Say what you got:
Serial.print("I received: "); //This never shows on the B-side
Serial.println(incomingByte, DEC);
}
}
How do I fix this problem?

Answer 1

You have to use a SoftwareSerial(RX,TX) for the XBee and the Serial for printing the output into the pc.
RX and TX of SoftwareSerial must be linked to the DOUT and DIN pin of the module into the Wireless Proto shield:
#include <SoftwareSerial.h>
// Connect pin 10 of Arduino to DOUT of Wireless Proto shield
uint8_t ssRX = 10;
// Connect pin 11 of Arduino to DIN of Wireless Proto shield
uint8_t ssTX = 11;
SoftwareSerial nss(ssRX, ssTX);
void setup() {
Serial.begin(19200);
nss.begin(19200);
Serial.println("Serial works");
}
void loop() {
if (nss.available()){
Serial.println("received packet:");
for(int i=0;i<25;i++){
Serial.print(nss.read(),HEX);
Serial.print(",");
}
Serial.println();
}

Answer 2

Many of the boards require the pull-up resistor on DIN to be enabled.
According to some sources this pull-up is enabled by default on the Digi Xbee module.
To ensure it is enabled or to enable it:
Put your Xbee module in a USB explorer and use X-CTU to check the PR configuration.
DIN is on bit 7 for the Xbee Pro S1, so in that case you need the last bit to be 1.
I put it like this: 00000001
Than you convert it to hex (01 in my case) and write that value to the Xbee module with X-CTU.
So it is an electronics issue and not a programming issue.