Serial echo for 433Mhz RF transmitter

Projects Programming
8

const char *msg = "Hello Shawn ";

will say that msg is a pointer to a char. Above that it is a const char pointer saying it is immutable.
The size (#bytes) is determined by the compiler compile time.

#include <VirtualWire.h>

char buffer[64]; 
int idx = 0;

int RF_TX_PIN = 12;
int Boot1 = 0; 

void setup()
{
  Serial.begin(9600);
  vw_set_tx_pin(RF_TX_PIN); // Setup transmit pin
  vw_setup(9600); // Transmission speed in bits per second.
}
 
void loop()
{
   // fill buffer with chars from 
   while (Serial.available() > 0) 
   {
    char c = Serial.read();
    buffer[idx] = c;
    idx++;
    buffer[idx] ='\0' ;  // keep the char array null terminated.
  }
  
  
  if (idx > 0 )
  {
    vw_send((uint8_t *)buffer, idx);  // Send message
    idx = 0;
    buffer[idx] = '\0';
    delay(400);
    Serial.println(" Message sent!");
  }      
}