ch55xduino uses SDCC for compiling. Therefore no c++ syntax is allowed.

try using the underscore instead of the dot.
e.g.
Serial1_println("Hello World");

and for output at P3.1 Serial0_println();

Hello Thomas,

Thanks for your suggestions, unfortunately I'm still not getting any 
data out on ant of the ports.

I have tried to connect my serial capture program ( RealTerm ) to any 
port without result.

When I connect Rx to TX my serial capture program, the capture program 
echo what I type, so I'm sure the capture program works fine.

I also have no compile error, so looks like CHxxDuino accept:
- Serial0_println("Hello World");
- Serial1_println("Hello World");

USBSerial_println("Hello World"); works fine ! using Arduino Serial 
Monitor.

Any other suggestions ?

void setup() {
}

void loop() {
Serial0_println("Hello World");   // print to P1.7
Serial1_println("Hello World");   // print to P3.1
USBSerial_println("Hello World"); // print to USB ( Works fine )
delay(100);
}

I dont use Arduino code on that board, so my knowledge is very limited.

But here is the thing:
Output on TX0 or TX1 usually requires to TI =1 (U1TI = 1) in Non 
Interrupt mode to signal the transmiter is empty. I suppose this is done 
in Serial0_begin() and Serial1_begin().


void setup() {
  Serial0_begin(9600);
  Serial1_begin(9600);
}

void loop() {
Serial0_println("Hello World0");   // print to P1.7
Serial1_println("Hello World1");   // print to P3.1
USBSerial_println("Hello World");  // print to USB ( Works fine )
delay(100);
}

I appreciate your advice, but regrettably I'm still not able to pull any 
data out of any of the ports.

Pierre B. wrote:
> I appreciate your advice, but regrettably I'm still not able to pull any
> data out of any of the ports.

Could You already successfully run any of the examples?
Maybe Your problem is located in a lower level.

Best regards
Klaus