Software serial not working with Stalker v2.3

Hi Seeed,

I have a Stalker 2.3 and a UARTsBee connected to it (3.3V set). The Stalker is connected to a 6V battery for power.
The problem is that I can’t get software serial to work in the UARTs->Stalker direction. The other direction works just fine.

The code I’m using to demonstrate the issue follows:

#include <SoftwareSerial.h>
#define softRX  10
#define softTX  11

SoftwareSerial softSerial(softRX, softTX);

void setup () 
{
   softSerial.begin(4800);
   softSerial.println("INIT");
   if (! softSerial.isListening())
     softSerial.println("ERROR: Software Serial is not listening!"); 
}

void loop()
{
  while(softSerial.available()) {
    softSerial.print("softSerial available: ");
    softSerial.println((char)softSerial.read());
  }
}

As you can see it’s a very simple piece of code. I have verified correct RX-TX connectivity between UARTSBee and the Stalker pins (10 & 11). If I print something to the softSerial I can read it on the serial monitor, however softSerial.available() never returns > 0, no matter what I’m typing on the serial monitor. I have tested this same setup/code with other Arduino boards and it works as expected. It’s only with the Stalker that doesn’t work. Again, reading from software serial is working, writing is not working. This is bizarre.

I’m stuck with this, because I really need SoftwareSerial in my project. Any idea would be greatly appreciated.

Regards
Alex