gtr/osc32final/SLIPEncodedBluetoothSerial.cpp

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#include "SLIPEncodedBluetoothSerial.h"
#include "BluetoothSerial.h"
/*
CONSTRUCTOR
*/
//instantiate with the tranmission layer
//use BluetoothSerial
SLIPEncodedBluetoothSerial::SLIPEncodedBluetoothSerial(BluetoothSerial &s){
serial = &s;
rstate = CHAR;
}
static const uint8_t eot = 0300;
static const uint8_t slipesc = 0333;
static const uint8_t slipescend = 0334;
static const uint8_t slipescesc = 0335;
/*
SERIAL METHODS
*/
bool SLIPEncodedBluetoothSerial::endofPacket()
{
if(rstate == SECONDEOT)
{
rstate = CHAR;
return true;
}
if (rstate==FIRSTEOT)
{
if(serial->available())
{
uint8_t c =serial->peek();
if(c==eot)
{
serial->read(); // throw it on the floor
}
}
rstate = CHAR;
return true;
}
return false;
}
int SLIPEncodedBluetoothSerial::available(){
back:
int cnt = serial->available();
if(cnt==0)
return 0;
if(rstate==CHAR)
{
uint8_t c =serial->peek();
if(c==slipesc)
{
rstate = SLIPESC;
serial->read(); // throw it on the floor
goto back;
}
else if( c==eot)
{
rstate = FIRSTEOT;
serial->read(); // throw it on the floor
goto back;
}
return 1; // we may have more but this is the only sure bet
}
else if(rstate==SLIPESC)
return 1;
else if(rstate==FIRSTEOT)
{
if(serial->peek()==eot)
{
rstate = SECONDEOT;
serial->read(); // throw it on the floor
return 0;
}
rstate = CHAR;
}else if (rstate==SECONDEOT) {
rstate = CHAR;
}
return 0;
}
//reads a byte from the buffer
int SLIPEncodedBluetoothSerial::read(){
back:
uint8_t c = serial->read();
if(rstate==CHAR)
{
if(c==slipesc)
{
rstate=SLIPESC;
goto back;
}
else if(c==eot){
return -1; // xxx this is an error
}
return c;
}
else
if(rstate==SLIPESC)
{
rstate=CHAR;
if(c==slipescend)
return eot;
else if(c==slipescesc)
return slipesc;
else {
// insert some error code here
return -1;
}
}
else
return -1;
}
// as close as we can get to correct behavior
int SLIPEncodedBluetoothSerial::peek(){
uint8_t c = serial->peek();
if(rstate==SLIPESC)
{
if(c==slipescend)
return eot;
else if(c==slipescesc)
return slipesc;
}
return c;
}
//the arduino and wiring libraries have different return types for the write function
#if defined(WIRING) || defined(BOARD_DEFS_H)
//encode SLIP
void SLIPEncodedBluetoothSerial::write(uint8_t b){
if(b == eot){
serial->write(slipesc);
return serial->write(slipescend);
} else if(b==slipesc) {
serial->write(slipesc);
return serial->write(slipescesc);
} else {
return serial->write(b);
}
}
void SLIPEncodedBluetoothSerial::write(const uint8_t *buffer, size_t size) { while(size--) write(*buffer++); }
#else
//encode SLIP
size_t SLIPEncodedBluetoothSerial::write(uint8_t b){
if(b == eot){
serial->write(slipesc);
return serial->write(slipescend);
} else if(b==slipesc) {
serial->write(slipesc);
return serial->write(slipescesc);
} else {
return serial->write(b);
}
}
size_t SLIPEncodedBluetoothSerial::write(const uint8_t *buffer, size_t size) { size_t result=0; while(size--) result = write(*buffer++); return result; }
#endif
void SLIPEncodedBluetoothSerial::begin(String name){
serial->begin(name);
}
//SLIP specific method which begins a transmitted packet
void SLIPEncodedBluetoothSerial::beginPacket() { serial->write(eot); }
//signify the end of the packet with an EOT
void SLIPEncodedBluetoothSerial::endPacket(){
serial->write(eot);
}
void SLIPEncodedBluetoothSerial::flush(){
serial->flush();
}