Bidirectional Communication with Collision Avoidance Since SoftwareSerial is half-duplex, implement a simple protocol:
SoftwareSerial.h is a powerful but fragile tool. It turns any two pins into a serial port, enabling multi-device Arduino projects on a budget. However, its software-timed nature means it cannot replace hardware serial for high-speed, high-reliability, or interrupt-heavy applications. softwareserial.h library
void sendString(SoftwareSerial &ss, char *msg) ss.listen(); // Ensure we're not receiving delay(1); // Allow any pending RX to finish ss.print(msg); char *msg) ss.listen()