SoftwareSerial uses precise timing loops and digital pin manipulation to:
void loop() // Continuously read from software serial while (mySerial.available()) char c = mySerial.read(); Serial.print(c); // echo to hardware serial softwareserial h
: Communicating with GPS modules , GSM/LTE shields, or Bluetooth modules simultaneously. SoftwareSerial uses precise timing loops and digital pin
| Feature | Hardware Serial (UART) | SoftwareSerial | |---------|------------------------|----------------| | CPU load | ~0% (DMA/hardware shift register) | High (50–90%) | | Simultaneous TX/RX | Full duplex | Half duplex | | Max baud rate | >2 Mbps (board dependent) | 38400 bps (reliable) | | Buffer size | 64–256 bytes (hardware FIFO) | 64 bytes (software) | | Number of ports | Limited (1–4 on AVR) | Unlimited (any pins) | | Interrupt safe | Yes (non-blocking ISR) | No (disables interrupts) | softwareserial h