2.1 KiB
SoftSerial library
The SoftSerial library is exactly the same as the SoftwareSerial library but used with the TinyPinChange library which allows to share the "Pin Change Interrupt" Vector.
SoftwareSerial monopolizes the Pin Change Interrupt Vector and do not allow sharing.
With SoftSerial, it's possible. Don't forget to #include TinyPinChange in your sketch!
Additionally, for small devices such as ATtiny85 (Digispark), it's possible to declare the same pin for TX and RX. Data direction is set by using the new txMode() and rxMode() methods.
Some examples of use cases:
- half-duplex bi-directional serial port on a single wire for debuging purpose
- half-duplex serial port to interface with Bluetooth module
- half-duplex serial port to interconnect an arduino with another one
Supported Arduinos:
- ATmega368 (UNO)
- ATmega2560 (MEGA)
- ATtiny84 (Standalone)
- ATtiny85 (Standalone or Digispark)
- ATtiny167 (Digispark pro)
Tip and Tricks:
Develop your project on an arduino UNO or MEGA, and then shrink it by loading the sketch in an ATtiny or Digispark (pro).
API/methods:
-
The SoftSerial library uses the same API as the regular SoftwareSerial library:
- begin()
- end()
- available()
- read()
- listen()
- isListening()
- overflow()
- flush()
-
Two additional methods are used to manage the serial port on a single pin:
- txMode()
- rxMode()
Design considerations:
The SoftSerial library relies the TinyPinChange library for the RX pin. This one shall be included in the sketch as well.
On the arduino MEGA, as all the pins do not support "pin change interrupt", only the following pins are supported for the RX pin:
- 10 -> 15
- 50 -> 53
- A8 -> A15
On other devices (ATmega328, ATtiny84, ATtiny85 and ATtiny167), all the pins are usable.
Contact
If you have some ideas of enhancement, please contact me by clicking on: RC Navy.