Hi,

GND of supply is connected to GND of Serial Port.

In fact, I manage to get bytes @ 9600 bps but after few ms bytes are corrupted.

I’ll try at lower baud rates.

This device uses 3.3V and I connect its TX pin directly to Arduino2009 maybe commutation time is too important (need a 5V 3.3V level shifter)

@19200 everything is corrupted.

Will try at 4800 bps and tell you.

Regards

Hi,

To give more info.

Work wery well @4800bps

So I need to test it with a level shifter.

Another work is to modify NewSoftSerial to manage 2 active port at the same time.

I need it because I want to get bytes from a GPS and this board without missing any byte.

Will see if I achieve to do that.

If you have info to help me….

Regards.

I will waiting for NewSoftSerial to support Arduino Mega.
I think that’s cool and useful.
thank you very much for excellent lib.

Hi Michael,

great work. I was looking for it since long. I have two serial devices connected to my Arduino Duemilanove. One to the Rx/Tx and the other to pin 2 and 3. I want to read/write using micro-controller on pin 2/pin 3 device and want to use PC to read and write rx/tx (pin 0/ pin 1) device. but problem is both devices will wait for the serial data to arrive, I want to make priority of device on Pin0/pin1 high.

You said that we cannot use the code like:

void loop()
{
if (device1.available() > 0)
{
int c = device1.read();
…
}
if (device2.available() > 0)
{
int c = device2.read();
…
}
}

then how can i wait for data on both serial ports as data is received my and analyzed by micro-controller in both cases?. I can also do the two tasks one after the other but how will then i wait for data without using device1.available() and device2.available()? Will i have to use device1.begin() and device1.end() before waiting for device 2.

thanks!

Does anyone know of a problem using the NewSoftSerial and I2C (wire.h)? I recently rewrote a program to use the NewSoftSerial package, but when it starts transmitting the data via I2C, the Arduino freezes.

Hi,
great lib!
I have a (maybe noobish) question: Is it possible to use 9-Bit (9n1) with NewSoftSerial?
I will need to get 9n1 from NewSoftSerial and send it (modified) over the Hardware UART to the PC.
Maybe a hit which lines i would need to modifiy would help…

Thanks!

For 9n1 i guess i would need to change the [uint8_t d] to uint16_t? Also the use of the bitmask could be a problem because it can only hold 8-bit?!
Seem to me it might be a bit (:D) more complicated than i first thought….atlast for me.
Maybe someone might have some fun to make 9n1 available for NSS? :)

Hello Mikal,
Great job here !
Is there a target date for Arduino Mega support ?
Thanks :)
Rico

It’s a great library. Thanks anyway.

However, few bytes might be lost with a long bytes input at once.
For baud rate: 9600, with updated values for parameter: rxcenter in the DELAY_TABLE
, the problem is fixed.

The values used in my sample are list as following:
{ 9600, 175, 236, 236, 233, },

I use Duemilanove in my project.

I seem to be having a problem with NewSoftSerial 10c. I’m using it with my LS20031 gps unit, a Duemilanove and your TinyGPS library. I’ve changed the nss baud to that of my gps, 57600, and tried several different rx pins but it just seems to hang. My monitor stops after printing ‘size of TinyGPS 103′. If I comment out the nss lines and use pin 0 I get data. Am I missing something?

Dave

Hi Mika,
I’m currently facing issues with native soft serial and my Mega board.
I really need to move on NewSoftSerial with my Mega board quickly.
So, I can not wait for Arduino 1.0 :-(

Is there a way (beta version or other hack) to get NewSoftSerial running with Megaboard ?

Thanks !
Rico

I dropped the baudrate again, this time to 9600. All seems well. Thanks,

Dave

Hi,

Thanks for your nice NewSoftSerial library. I just wanted to ask what baud rate you had reliably achieved for receiving data? I wrote a quick program that counts up the number of bytes received and displays the count when you press SPACE over a serial link.

For bursts of a few bytes, I’m fine at 19200 bps, but if I cut-and-paste 20+ bytes into my terminal at once, then I get about 5% drop rate. Is that normal?

Also, how does your library cope with full duplex – what happens if data is received whilst other data is being sent out?

Thanks,

Chris.

I’m trying to verify the correct retrieving of serial information with NewSoftSerial library .
I wire the physical UART from Arduino (pins 0 and 1) to two other digital pins (2,3) that are setup as with Newsoftserial library as a new software Serial in the following way:

0 RX — 3 TX
1 TX — 2 RX

Then , with the following code, I try to print what has been read by the created software Serial.

The problem is that information read doesn’t correspond to the information sent. And I don’t know if there’s a problem with the printing or really in the communication.
I send “2E” and in return I always receive (at least it’s what is displayed) “32″

#include

NewSoftSerial nsSerial(2,3);

void setup()
{
Serial.begin(9600);
nsSerial.begin(9600);
//digitalWrite(2,HIGH);
Serial.print(0xAA,HEX);
delay(150);
if (nsSerial.available()>0)
{
Serial.print(nsSerial.read(),HEX);
}
}

void loop()
{

}

Thanks in advance for any help to find what I’m doing wrong

@Mikal . Thanks!. That was the point. I was sending more than one byte . Now is working fine . I wrote the following code for the testing and everything is ok now for any kind of data format (The code read all the bytes received). I saw it’s important to add a delay between the sending and the reading (50 ms) .

#include

const byte rxPin = 2;
const byte txPin = 3;
int countOffset =0;
int bytesRead=0;

NewSoftSerial nsSerial(2,3);

void setup()
{
Serial.begin(19200);
nsSerial.begin(19200);

Serial.print(0x2A,BYTE); //
delay(50); //
countOffset = nsSerial.available();
if ( countOffset > 0 )
{
while(bytesRead < countOffset)

{
Serial.print(nsSerial.read(),HEX);
bytesRead ++;
}
}
Serial.println();
Serial.print(countOffset);Serial.println(" bytes read");
}

void loop()
{
}

Hi Mikal

I want to use this library to communicate with a distance sensor (SRF485). The problem is this sensor uses 2 stop bits for both RX and TX. Is it possible to modify the library for 2 stop bits instead of 1 for both printing and reading? If so, can you please advise?

Thanks
Frits

Hi,

Thanks for the library. I’m having a little trouble getting it to read data from a GPS. I’m using a very basic sketch (attached), but I just get strings of garbage on the screen

I can read the GPS data using hyperterminal without problems, it auto-detects the connections settings as 4800 baud, 8 bit, no parity. The data displayed by hyperterminal is fine, so I know the GPS is working.

Any suggestions appreciated.

Regards

Mike

#include

NewSoftSerial mySerial = NewSoftSerial(2, 3);

#define BUFFSIZ 90 // plenty big
char buffer[BUFFSIZ];
char buffidx;

void setup()
{
Serial.begin(4800);
mySerial.begin(4800);
Serial.println(“\n\rNewSoftSerial + GPS test”);
}

void loop()
{
Serial.print(“\n\rread: “);
readline();
}

void readline(void) {
char c;
buffidx = 0; // start at begninning
while (1) {
c=mySerial.read();
if (c == -1)
continue;
Serial.print(c);
if (c == ‘\n’)
continue;
if ((buffidx == BUFFSIZ-1) || (c == ‘\r’)) {
return;
}
buffidx++;
}
}

Any word on when NewSoftSerial will be available for the Mega? I can send ok but can’t receive, using my Mega with the TSS. Primarily, I wish to use NewSoftSerial between these two devices.

Having a bit of a problem with what i think is down to a writing baud rate issue..

I have the PC connected to the Duemilanove via USB, then pin 3 of the arduino (Tx) connected to the serial connection on a Milford Instruments LCD display screen. Data sheet – http://www.milinst.co.uk/shop/LCDs/pdf/6_201.pdf which accepts baud rates of 9600 or 2400 depending on the baud jumper, is 8bit, no parity and one stop bit.

Basically the Duemilanove should be acting as a USB to serial converter. The sketch is as follows:

#include

NewSoftSerial lcd(2, 3);

void setup()
{
pinMode(13, OUTPUT);
digitalWrite(13, HIGH);
Serial.begin(9600);
lcd.begin(9600);
}

void loop()
{
if(Serial.available())
{
char c = Serial.read();
lcd.print(c);
Serial.print(c);
Serial.print((bool) lcd.overflow());
}
}

Should be reading from Serial (1 char at a time) then printing to the LCD display via pin 3 (additional Serial prints for debugging)..

At the PC side I have a python script to send the commands (clear the LCD display, reset the cursor position and send some ‘test’ text).

At 9600 baud either side of the Arduino, data is getting through to the display screen but about 50% of the time at least 1 of the 4 characters that make up the initial string is garbled. However the messages that come back through the USB serial port to the PC are always correct and there’s no overflow.

Connecting the LCD display directly to the PC with a serial cable and with a USB to serial converter (PL2303) it works 100% of the time fine. I’m assuming it’s got to be related to the NSS write function..?

I’m trying to get data from a sensor that sends data at 1200 baud. My code looks a lot like g’s above. When the arduino is reset, I get the sensor data. All subsequent tries fail. The old softserial library is able to read repeatedly, so I’m pretty sure it isn’t a hardware problem.
Is this a baud rate problem?

Since I will have multiple RO devices, can they all share a TX pin?

Code that doesn’t work:
NewSoftSerial….h2o1(7,9)

h2o1.flush(); // flush old stuff before powering on
digitalWrite(powerpin1,HIGH); // excite sensor and wait for device to settle.
delay(DECAGONDELAY); // at this point sensor should have sent everything

while(h2o1.available()>0) {
c=h2o1.read();
if (c == -1) { continue; }
if (c == ‘\n’) { continue;}
if (c == 0 ) { continue;} // null sometimes sent at beginning?
if ((buffidx == DECAGONBUFF-1) || (c == ‘\r’)) {
buffer[buffidx] = 0;

Serial.println(millis() -startreadline); // tune how long we delay
digitalWrite(powerpin1,LOW); // reset sensor
return(1);
} else {
buffer[buffidx]= c;
buffidx++;
}
}

Serial.println(“failed”);
digitalWrite(powerpin1,LOW); // reset sensor
return(0);

I tightened up my code, and now NewSoftSerial will read 1-3 sensor readings successfully. Then it will fail from then on. Using the goodnight moon code & manually exciting the sensor I get the same result: 1-3 good readings, then failure from then on.

This is using OS X Arduino 18, and a Duemilanove 328.

Never mind, turns out I had a problem with the sensor. When I set up a 2nd arduino to act as a sensor simulator, NewSoftSerial worked without flaw.

Hi Mikal,

I have a problem with using the NNS library and the hardware GPS on a FIO board which I posted here:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1284169934/2#2

Do you know if it’s possible to change the interrupt or library somehow to patch this issue? (ie get the 4800 BAUD while fooling the arduino somehow it’s running at 57600?).

If not, do you know if it’s possible to get the em406a GPS serial running at 57600 BAUD?

Many thanks for all your hard work!

Hi Mikal,

I am working on a project that requires IrDA interface. I don’t need particularly fast comms so I only want to consider 9600 baud or even 2400 baud (both rates are supported by the IrDA spec). The IrDA standard defines the bit length as 3/16 of the RS232 equivalent hence a normal RS232 hardware UART can’t “talk” IrDA. What would be involved in modifying NSS to enable it to talk (and recieve) IrDA?

I know I can get a h/w “glue” IC that deal with RS232 to IrDA conversion but I am looking for a no hardware solution.

I am new here. May you show me how to install your NewSoftSerial?

That NewSoftSerial inherits from Print is too cool. What I need is this library to support the SPI in Master or Slave modes! That way, many atMegas can communicate reliably at high speeds. I am designing open source shields with atMega168s; some as SPI Masters, some as SPI Slaves. I know the Ethernet lib uses the SPI, I just want SPI as a serial port. Thanks so much for these tools.
Mark Adams

Mikal,

Actually, both the SPI and the TWI hardware on the Mega168 could be used as general purpose 8 bit serial ports. Years ago, I did a bit-bang serial port emulation and know how hard it is to catch incoming data correctly. These two hardware peripherals free the real time to mostly interrupt driven software allowing higher baud rates and less problems. To develop this, I guess you need someone on the shield side using straight GCC. I am thinking to change my design to just use the native UART. So, I will not likely need these interfaces or your soft ones. Thanks and good luck, when I get something out here, I will drop you a line.

Mark

Mikal,

I’m just getting started with Arduino serial comms. I need to interface two serial devices and was planning to use your NSS library. I don’t have the necessary h/w yet,so I can’t test anything, but I’m struggling to understand how your library maintains two asynchronous input streams. My devices cannot be controlled so will send data when they feel like it. Looking at NewSoftSerial.cpp, it looks like bits sent by a device whilst another is being read will be lost – or an I missing something?

Mikal,
A couple things I see looking through the NewSoftSerial code..
1. Interupts are disabled on TX for the length of the char.
This could…
cause problems to others at low baud rates.
TX will trash any RX data incoming
A loop back connection can never work.

Wouldn’t an interupt driven TX help?

David

Hey Mikal,

I wrote the “Mega” (Arduino Mega and Mega 2560) changes for NewSoftSerial.

Beware, though: NewSoftSerial will only be able to *receive* on pins

10, 11, 12, 13,
50, 51, 52, 53,
and 62, 63, 64, 65, 66, 67, 68, 69

That’s it.

So if you have a shield or something else that “normally” uses a NewSoftSerial pin in the 0-9 range, it WILL NOT WORK.

(You can, however, *transmit* on pretty much any pin).

As a bonus, I’ve already updated it to support Stream.h (you will need to have the latest Arduino IDE – V0021+).

http://tinyurl.com/newsoftserial-bh-mod

b

No problem, Mikal, go right ahead.

Since I’m now maintaining the libraries for Wiring, NewSoftSerial will become the new SoftSerial library for Wiring (the father of Arduino – http://wiring.org.co/). Expect to see it in Version 0028.

b