Allows normal IO pins to be used as bit bashed UART pins


Example Usage

#include <SoftwareSerial.h>

SoftwareSerial mySerial(8, 7); // RX=pin #, TX=pin #
//This also works:
//SoftwareSerial mySerial(PA2, PA3); // RX=pin #, TX=pin #

void audio_init (void)
  //Set the baud rate for the SoftwareSerial port
  mySerial.println("Hello, world?");

void tx_packet (void)
  byte tx_data[4];


  tx_data[0] = 0x00;
  tx_data[1] = 0x01;
  tx_data[2] = 0x02;
  tx_data[3] = 0x03;
  mySerial.write(&tx_data[0], 4);

Receiving Data

Note you can define unlimited software serial ports, but only 1 can be set to receive at a time.

  //Enable RX (will occur in background using irq's)


  while (mySerial.available() > 0)
    char data =;

  char data =;
  if (data != -1)
    //Byte received

Using only 1 pin

Using for RX only

Defining both pins as PA5 on an ATtiny841 and using to receive worked for us.



RX on pin 2 (RB2) would not work (no explanation found as to why).
RX on pin 5 (PA5) works.

Does SoftwareSerial use hardware timer?

No, see explanation here:

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