byte Fastwire::write(byte device, byte address, byte value)
{
byte twst,retry;
retry=2;
do
{
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO) | (1<<TWSTA) ;
if (!waitInt()) return 1;
twst=TWSR & 0xF8;
if (twst != TW_START && twst != TW_REP_START) return 2;
TWDR = device&0xFE; // send device address without read bit (1)
TWCR = (1<<TWINT) | (1<<TWEN);
if (!waitInt()) return 3;
twst=TWSR & 0xF8;
}
while (twst == TW_MT_SLA_NACK && retry-- > 0);
if (twst != TW_MT_SLA_ACK) return 4;
TWDR = address; // send data to the previously addressed device
TWCR = (1<<TWINT) | (1<<TWEN);
if (!waitInt()) return 5;
twst=TWSR & 0xF8;
if (twst != TW_MT_DATA_ACK) return 6;
TWDR = value; // send data to the previously addressed device
TWCR = (1<<TWINT) | (1<<TWEN);
if (!waitInt()) return 7;
twst=TWSR & 0xF8;
if (twst != TW_MT_DATA_ACK) return 8;
return 0;
}
byte Fastwire::readBuf(byte device,byte address,byte *data,byte num)
{
byte twst,retry;
retry=2;
do
{
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO) | (1<<TWSTA) ;
if (!waitInt()) return 16;
twst=TWSR & 0xF8;
if (twst != TW_START && twst != TW_REP_START) return 17;
TWDR = device & 0xfe; // send device address to write
TWCR = (1<<TWINT) | (1<<TWEN);
if (!waitInt()) return 18;
twst=TWSR & 0xF8;
}
while (twst == TW_MT_SLA_NACK && retry-- > 0);
if (twst != TW_MT_SLA_ACK) return 19;
TWDR = address; // send data to the previously addressed device
TWCR = (1<<TWINT) | (1<<TWEN);
if (!waitInt()) return 20;
twst=TWSR & 0xF8;
if (twst != TW_MT_DATA_ACK) return 21;
/***/
retry=2;
do
{
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO) | (1<<TWSTA) ;
if (!waitInt()) return 22;
twst=TWSR & 0xF8;
if (twst != TW_START && twst != TW_REP_START) return 23;
TWDR = device|0x01; // send device address with the read bit (1)
TWCR = (1<<TWINT) | (1<<TWEN);
if (!waitInt()) return 24;
twst=TWSR & 0xF8;
}
while (twst == TW_MR_SLA_NACK && retry-- > 0);
if (twst != TW_MR_SLA_ACK) return 25;
for(uint8_t i=0;i<num;i++)
{
if (i==num-1)
TWCR = (1<<TWINT) | (1<<TWEN) ;
else
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA);
if (!waitInt()) return 26;
twst=TWSR & 0xF8;
if (twst != TW_MR_DATA_ACK && twst != TW_MR_DATA_NACK) return twst;
data[i]=TWDR;
}
return 0;
}
byte Fastwire::readBuf(byte device,byte address,byte *data,byte num)
{
unsigned long t=micros();
byte twst,retry;
retry=2;
do
{
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO) | (1<<TWSTA) ;
if (!waitInt()) return 16;
t=micros()-t;
Serial.print("duration1:");
Serial.println(t);
t=micros();
twst=TWSR & 0xF8;
if (twst != TW_START && twst != TW_REP_START) return 17;
t=micros()-t;
Serial.print("duration2:");
Serial.println(t);
t=micros();
TWDR = device & 0xfe; // send device address to write
TWCR = (1<<TWINT) | (1<<TWEN);
if (!waitInt()) return 18;
twst=TWSR & 0xF8;
t=micros()-t;
Serial.print("duration3:");
Serial.println(t);
t=micros();
}
while (twst == TW_MT_SLA_NACK && retry-- > 0);
if (twst != TW_MT_SLA_ACK) return 19;
t=micros()-t;
Serial.print("duration4:");
Serial.println(t);
t=micros();
TWDR = address; // send data to the previously addressed device
TWCR = (1<<TWINT) | (1<<TWEN);
if (!waitInt()) return 20;
t=micros()-t;
Serial.print("duration5:");
Serial.println(t);
t=micros();
twst=TWSR & 0xF8;
if (twst != TW_MT_DATA_ACK) return 21;
t=micros()-t;
Serial.print("duration6:");
Serial.println(t);
t=micros();
/***/
t=micros();
retry=2;
do{
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO) | (1<<TWSTA) ;
if (!waitInt()) return 22;
twst=TWSR & 0xF8;
if (twst != TW_START && twst != TW_REP_START) return 23;
TWDR = device|0x01; // send device address with the read bit (1)
TWCR = (1<<TWINT) | (1<<TWEN);
if (!waitInt()) return 24;
twst=TWSR & 0xF8;
}while (twst == TW_MR_SLA_NACK && retry-- > 0);
t=micros()-t;
Serial.print("duration7:");
Serial.println(t);
t=micros();
if (twst != TW_MR_SLA_ACK) return 25;
for(uint8_t i=0;i<num;i++)
{
if (i==num-1)
TWCR = (1<<TWINT) | (1<<TWEN) ;
else
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA);
if (!waitInt()) return 26;
twst=TWSR & 0xF8;
if (twst != TW_MR_DATA_ACK && twst != TW_MR_DATA_NACK) return twst;
data[i]=TWDR;
}
t=micros()-t;
Serial.print("duration8:");
Serial.println(t);
return 0;
}
