Print nothing when using SoftwareSerial and altSoftSerial on Arduino Uno Mini.
#include <AltSoftSerial.h>
#include <SoftwareSerial.h>
SoftwareSerial SoftSerial(2,3);
AltSoftSerial AltSerial;
void setup() {
Serial.begin(9600);
SoftSerial.begin(9600);
AltSerial.begin(9600);
Serial.println("Hello, This is Serial.");
SoftSerial.println("Hi, This is SoftSerial.");
AltSerial.println("Morning, This is AltSerial.");
}
void loop()
{
}Result:
Hello, This is Serial.
Where do you expect to see the output when using SoftwareSerial & AltSoftSerial?
If COM5 is where you think they will print, then that is incorrect. From what I can tell in your video, the output you see on COM5 is correct for the code you posted.
The detail on your video is, for the most part, unreadable.
I'm surprised that compiles without errors, and wonder how the timer conflicts are resolved. Maybe they aren't.
SoftwareSerial uses pin-change interrupts to trigger reception (and transmission uses calibrated while loop with delays) so only AltSoftSerial requires a timer
to @ggman226 you need to connect a Serial to USB converter (like the FTDI thingy) and open 2 other Serial monitors on those ports to see what's sent on the two Software Serial ports
FTDI thingy:
Why COM5 is not correct?, what would I do can get the data from SoftwareSerial and AltSoftSerial print?
See post #4.
You need to understand what these 2 lines do:
The first creates a software serial port (completely separate from the hardware serial port that connects to the USB-serial converter that your PC sees as COM5). That serial port uses pins 2&3. In order to view the output from that serial port you need a separate USB-serial adapter. Like the one shown to you in post #4.
The second also creates a further software serial port. This one uses pins 8&9 only. You need another USB-serial adapter to view the output from that one.
I think I understand how to let the SoftwareSerial print on Serial Monitor. thank you, guys.
It wouldn't be by trying to use pins 0 & 1 in the definition of SoftwareSerial would it?
Why do you need 3 serial ports, all to be seen by the IDE serial monitor on the same COM port? Perhaps you can describe your project as there may be an alternative solution available to you.
I was just wondering how they work out.
How a software serial port works?
The basics are pretty simple. For transmission, you have to change the state of an output pin to appear like a UART frame - i.e. Start bit, data bits, parity bit, stop bit(s). The output pin has to change at a rate defined by the baud rate. Reception is similar, in that you detect the start bit and then sample the input pin at a rate defined by the baud rate to reconstruct the byte.
There's more to it, especially when receiving data, but that's the basics.
Different software serial ports use different techniques to achieve the same results. Some can send and receive at the same time, whilst others cannot. Software serial ports operate with much lower baud rates than true hardware serial ports- usually limited to a maximum of around 19200 or 38400 baud. The faster the processor, the higher the baud rate, but they aren't really a substitute for a full hardware serial port.
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