Gets the number of bytes (characters) available for reading from the serial port. This is data that’s already arrived and stored in the serial receive buffer. The available() inherits from the Stream utility class.
port.available()
none
a integer value which represents the size of received data
#include <PhpocExpansion.h>
#include <Phpoc.h>
#define BUFFER_SIZE 100 // read and write buffer size, reduce it if memory of Arduino is not enough
byte spcId = 1;
ExpansionSerial port(spcId);
byte rwbuf[BUFFER_SIZE]; // read and write buffer
void setup() {
Serial.begin(9600);
while(!Serial)
;
Phpoc.begin(PF_LOG_SPI | PF_LOG_NET);
Expansion.begin();
port.begin("115200N81N");
}
void loop() {
int txfree = port.availableForWrite();
// Get the number of bytes available for reading
int rxlen = port.available();
if(rxlen > 0) {
if(rxlen <= txfree) {
int rwlen; // read and write length
if(rxlen <= BUFFER_SIZE)
rwlen = rxlen;
else
rwlen = BUFFER_SIZE;
// receive data
rwlen = port.readBytes(rwbuf, rwlen);
// send data
port.write(rwbuf, rwlen);
// print data to serial monitor of Arduino IDE
Serial.write(rwbuf, rwlen);
}
}
delay(1);
}