All sofware serial libraries return junk chars?

Forum 2005-2010 (read only) Software Interfacing
21

Right .. oscilloscope purchased.
I did also find that turning local echo off on the wifi device helps alot ..

Code looks like this now:

#include <NewSoftSerial.h>

NewSoftSerial mySerial(3, 2); //rx,tx

void setup()  
{
  Serial.begin(9600);
  Serial.println("Start");

  // set the data rate for the NewSoftSerial port
  mySerial.begin(9600);
  mySerial.println("AT+iE0"); //set local echo off
  delay(500);
  while (mySerial.available())
{
  Serial.print((char)mySerial.read());  

} 

  mySerial.println("AT+iRP19"); // reads some adc value from device
 delay(500);
  while (mySerial.available())
{
  Serial.print((char)mySerial.read());  

} 


  
}

void loop()                     // run over and over again
{
   mySerial.println("AT+i"); // should return i/ok
  delay(500);
  while (mySerial.available())
{
  Serial.print((char)mySerial.read());  

} 
   
 
 delay(1000);
 
}

And output like this:

Start
I/OK
ADC value = 55
I/OK
I/OK
..... {some I/OK removed to ease reading}
I/OK
I/OK
¤/OK
I/OK
I/OK
RéjªHøI/OK
I/OK
I/OK
I/OK
I/OK
¤/OK
I/OK
I/OK
RéjªHøI/OK
I/OK
I/OK
I/OK
I/OK
I/OK

Since there is a nice delay in the void loop its easy to catch the different pulse trains on the scope.
I have the probe connected to ground and the rx pin of the arduino (5v side). The pulses are all nice and square and come out very close to 5V with a 30uS rise time. Ripple voltage on the 3v supply is less than 20mV.

The scope is a Philips/Fluke pm3350 digital storage at 50MHz and has a register store function. This allows you to 'save' a pulse train and then overlay it on the screen together with the current pulse train triggered.
Problem is the junk chars output (RéjªHø) and the correct output (I/OK) generate exactly the same pulse train! :o

Anyone ideas where the software may be getting the junk chars from or am I not using the scope correctly? :-?