unsigned char oneWire_TouchBit(unsigned char sendbit){
unsigned char status;
int poll_count = 0;
i2c_start(slaves);
i2c_write(slaves, DS2482_I2C_ADDR | I2C_FLAG_WRITE);
i2c_write(slaves, DS2482_CMD_1WSB);
i2c_write(slaves, sendbit ? 0x80:0x00);
i2c_start(slaves);
i2c_write(slaves, DS2482_I2C_ADDR | I2C_FLAG_READ);
status = i2c_read(slaves, I2C_READ_ACK);
do{
status = i2c_read(slaves, status & DS2482_STATUS_1WB);
} while ((status & DS2482_STATUS_1WB) && (poll_count++ < POLL_LIMIT));
i2c_read(slaves, I2C_READ_NACK);
i2c_stop(slaves);
if(poll_count >= POLL_LIMIT){
DS2482_reset();
return false;
}
// check for single bit result
if(status & DS2482_STATUS_SBR)
return true;
else
return false;
}
//--------------------------------------------------------------------------
// DS2428 Detect routine that sets the I2C address and then performs a
// device reset followed by writing the configuration byte to default values:
// 1-Wire speed (c1WS) = standard (0)
// Strong pull-up (cSPU) = off (0)
// Presence pulse masking (cPPM) = off (0)
// Active pull-up (cAPU) = on (CONFIG_APU = 0x01)
//
// Returns: TRUE if device was detected and written
// FALSE device not detected or failure to write configuration byte
//
int DS2482_detect(unsigned char addr)
{
// set global address
I2C_address = addr<<1; // which we do not use!
// avr-Xinu is using a single DS2482 and a constant address
// TWI_SETUP_CMDBLOCK macro will not work with a variable address,
// but it would be an easy matter to OR an address into CommandBlock[0]
// for multiple DS2482s
// reset the DS2482 ON selected address
if (!DS2482_reset())
return FALSE;
// default configuration
c1WS = FALSE;
cSPU = FALSE;
cPPM = FALSE;
cAPU = 0x01;
// write the default configuration setup
if (!DS2482_write_config(c1WS | cSPU | cPPM | cAPU))
return FALSE;
return TRUE;
}
int ds2482_write_config(int8 config){
int8 read_config;
i2c_start();
i2c_write(DS2482_I2C_ADDR | I2C_FLAG_WRITE);
i2c_write(DS2482_CMD_WCFG);
I2C_write(config | (~config << 4)); //This makes the ones compliment in the top nibble ***Checked Working***
i2c_start();
i2c_write(DS2482_I2C_ADDR | I2C_FLAG_READ);
read_config = i2c_read(0);
i2c_stop();
// check for failure due to incorrect read back
if (config != read_config){
DS2482_reset();
return false;
}
return true;
}
//--------------------------------------------------------------------------
// Send 1 bit of communication to the 1-Wire Net and return the
// result 1 bit read from the 1-Wire Net. The parameter 'sendbit'
// least significant bit is used and the least significant bit
// of the result is the return bit.
//
// 'sendbit' - the least significant bit is the bit to send
//
// Returns: 0: 0 bit read from sendbit
// 1: 1 bit read from sendbit
//
unsigned char OWTouchBit(unsigned char sendbit)
{
unsigned char status;
int poll_count = 0;
struct twi_Command cb1, cb2;
uint8_t OWsb[2];
// 1-Wire bit (Case B)
// S AD,0 [A] 1WSB [A] BB [A] Sr AD,1 [A] [Status] A [Status] A\ P
// \--------/
// Repeat until 1WB bit has changed to 0
// [] indicates from slave
// BB indicates byte containing bit value in msbit
// I2C_start();
// I2C_write(I2C_address | I2C_WRITE, EXPECT_ACK);
// I2C_write(CMD_1WSB, EXPECT_ACK);
// I2C_write(sendbit ? 0x80 : 0x00, EXPECT_ACK);
// I2C_rep_start();
// I2C_write(I2C_address | I2C_READ, EXPECT_ACK);
// loop checking 1WB bit for completion of 1-Wire operation
// abort if poll limit reached
// status = I2C_read(ACK);
// do
// {
// status = I2C_read(status & DS2482_STATUS_1WB);
// }
// while ((status & DS2482_STATUS_1WB) && (poll_count++ < POLL_LIMIT));
// I2C_stop();
OWsb[0] = DS2482_CMD_1WSB; //1-Wire Single Bit command
OWsb[1] = sendbit ? 0x80 : 0x00;
cb1.slarw = DS2482_SLAVEADDRESS<<1|TW_WRITE;
cb1.data = OWsb;
cb1.dataLength = 2;
cb1.chain = &cb2;
cb2.slarw = DS2482_SLAVEADDRESS<<1|TW_READ;
cb2.data = &status;
cb2.dataLength = 1;
cb2.chain = (struct twi_Command *)0;
if ( twi_doCommand(&cb1) == SYSERR )
goto errorReturn;
while ( twi_doCommand(&cb2) == OK && (status & DS2482_STATUS_1WB) && (poll_count++ < POLL_LIMIT)) {
continue;
}
// check for failure due to poll limit reached
if (poll_count >= POLL_LIMIT)
{
errorReturn:
// handle error
// ...
DS2482_reset();
return 0;
}
// return bit state
if (status & DS2482_STATUS_SBR)
return 1;
else
return 0;
}
