uint8_t twi_read (uint8_t* data, enum twi_send_ack ack)
{
#if __AVR_ARCH__ <= 6
*data = TWDR;
TWCR = (1 << TWINT) | (1 << TWEN) | (ack << TWEA);
twi_wait();
uint8_t status = twi_status();
if (status == 0x50 || status == 0x58)
return 0;
else
{
//debug_pgm(PSTR("err twi_re"));
return 1;
}
#elif __AVR_ARCH__ >= 100
while ( (TWI.MASTER.STATUS & (1 << 5)) == 0); //wait for CLKHOLD
if ( (TWI.MASTER.STATUS & (1 << 2)) == 0)
debug_pgm(PSTR("BUSERR"));
TWI.MASTER.CTRLC = TWI.MASTER.CTRLC | ( (ack == NACK) << 2);
*data = TWI.MASTER.DATA;
return 0;
#endif
}
uint8_t twi_write (uint8_t data)
{
#if __AVR_ARCH__ <= 6
TWDR = data;
TWCR = (1 << TWINT) | (1 << TWEN);
twi_wait();
uint8_t status = twi_status();
if (status == 0x28 || status == 0x30)
return 0;
else
{
//debug_pgm(PSTR("err twi_wr"));
return 1;
}
#elif __AVR_ARCH__ >= 100
TWI.MASTER.DATA = data;
while ( (TWI.MASTER.STATUS & (1 << 6)) == 0); //wait for WIF
TWI.MASTER.STATUS |= (1 << 6);
return 0;
#endif
}
static int wait_twi_complete()
{
int status;
int timeout = systick_get_ms() + TWI_TIMEOUT;
do {
status = twi_status();
if (status <= 0) return status;
} while (systick_get_ms() < timeout);
return status;
}
uint8_t twi_restart (void)
{
#if __AVR_ARCH__ <= 6
TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTA);
twi_wait();
uint8_t status = twi_status();
if (status == 0x08 || status == 0x10)
return 0;
else
{
//debug_pgm(PSTR("error start twi"));
return 1;
}
#elif __AVR_ARCH__ >= 100
//on xmega start is automatically send on connect
TWI.MASTER.CTRLC = TWI.MASTER.CTRLC | (1 << 0);
return 0;
#endif
}
uint8_t twi_connect (enum twi_access_mode mode, uint8_t addr)
{
#if __AVR_ARCH__ <= 6
twi_restart();
//check for valid status
uint8_t status;// = twi_status();
/*if(status == 0x08 || status == 0x10)
return 0;
else {
debug_pgm(PSTR("error connect1 twi"));
return 1;
}*/
TWDR = (addr << 1) | mode;
//byte_to_hex((addr<<1)|mode);
TWCR = (1 << TWINT) | (1 << TWEN);
twi_wait();
status = twi_status();
if (status == 0x18 || status == 0x20 || status == 0x40 || status == 0x48 || status == 0xF8)
return 0;
else
{
//debug_pgm(PSTR("err twi_con"));
return 1;
}
#elif __AVR_ARCH__ >= 100
TWI.MASTER.ADDR = (addr << 1) | mode;
while ( (TWI.MASTER.STATUS & (1 << 6)) == 0); //wait for WIF
return 0;
#endif
}
uint8_t TwoWire::status(){
return twi_status();
}
