Xbee Series 2 works with Sparkfun USB Explorer but not Fio

Wireless & IoT
1

I have a pair of XBee 2mW PCB Antenna (Series 2, Zigbee Mesh) units. I have configured one as a Zigbee Coordinator API and one as a Zigbee End Device AT. When I plug them into the Sparkfun USB Explorers the two connect and I can send text from the End Device to the Coordinator. I use the X-CTU application to enter and view the text.

If I unplug the End Device Xbee unit from the Sparkfun USB explorer and plug it into an Arduino Fio I can no longer get it to work. I have confirmed that the Xbee unit is well seated, that it is powered up (through an LEDon the CTS line). I am sending using Serial.println() but nothing I send gets to the coordinator. I have even tried sending it a ‘+++’ command and AT commands but it never responds. Is there something additional I need to do in order to make it work with Fio? (Plugging it back into the USB Explorer and I can send).

I have tried using the FTDI connection to power it and the battery connection. Same result.

I have ensured that the PAN ID is the same on both.

I have ensured that neither one is sleeping (using CTS and ensuring the configuration doesn’t have sleep).

I have tried the Sparkfun shield with my Arduino Uno with the same result.

Here is the code I am using:

void setup()
{
  Serial.begin(9600);
}

void loop()
{
  Serial.print("Hello world");
  delay(1000);
}

Link to the units I got:

https://www.sparkfun.com/products/11217

Coordinator is Version 21A7, End Device is version A8A7.