static char i2cs_recv(void)
{
I2C_WAIT();
while( TW_STATUS != TW_SR_DATA_ACK ) {
I2C_ACK();
}
char c = TWDR;
I2C_ACK();
return c;
}
/**
* @brief Reads a block of data from the EEPROM.
* @param pBuffer : pointer to the buffer that receives the data read
* from the EEPROM.
* @param ReadAddr : EEPROM's internal address to read from.
* @param NumByteToRead : number of bytes to read from the EEPROM.
* @retval None
*/
void I2C_EE_BufferRead(uint8_t* pBuffer, uint16_t ReadAddr, uint16_t NumByteToRead)
{
I2C_START();
I2C_SEND_DATA(I2C_EEPROM_ADDRESS|EE_CMD_WRITE);
I2C_WAIT_ACK();
#ifdef EE_M24C08
I2C_SEND_DATA(ReadAddr);
I2C_WAIT_ACK();
#else
I2C_SEND_DATA((uint8_t)((ReadAddr & 0xFF00) >> 8));
I2C_WAIT_ACK();
I2C_SEND_DATA((uint8_t)(ReadAddr & 0x00FF));
I2C_WAIT_ACK();
#endif
I2C_START();
I2C_SEND_DATA(I2C_EEPROM_ADDRESS|EE_CMD_READ);
I2C_WAIT_ACK();
while (NumByteToRead) {
if (NumByteToRead == 1) {
*pBuffer =I2C_READ();
I2C_NO_ACK();
I2C_STOP();
}
else {
*pBuffer =I2C_READ();
I2C_ACK();
pBuffer++;
}
NumByteToRead--;
}
}
static void i2cs_send(char c)
{
I2C_WAIT();
while( TW_STATUS != TW_ST_SLA_ACK && TW_STATUS != TW_ST_DATA_ACK ) {
I2C_ACK();
}
I2C_SEND(c);
}
/* @brief Receive data from an I2C slave.
*
* Parameters for the '>' command:
* - I2C slave address (u8)
* - data size (u8) or 0
*
* If the data size is 0, the value is read from the first data byte and is the
* number of bytes to read after this first one. This is used to read protocol
* replies from the slave.
*/
static void cmd_i2c_recv(void)
{
const uint8_t addr = init_cmd_i2c();
if( addr == 0 ) {
return; // reply sent by init_cmd_i2c()
}
uint8_t size = recv_u8();
// poll the slave
do I2CM_START(); while( TW_STATUS != TW_START );
// slave address + Read bit (1)
I2C_SEND((addr<<1)+1);
#ifndef DISABLE_STRICT_CHECKS
if( TW_STATUS != TW_MR_SLA_ACK && TW_STATUS != TW_MR_SLA_NACK ) {
I2CM_STOP();
goto slave_i2c_error;
}
#endif
if( size == 0 ) {
// read the size in the first byte
I2C_ACK();
size = TWDR;
reply_success(size+1);
send_u8(size);
} else {
reply_success(size);
}
while( size-- != 1 ) {
I2C_ACK();
const uint8_t c = TWDR;
send_u8(c);
}
I2C_NACK();
send_u8( TWDR );
I2CM_STOP();
return;
#ifndef DISABLE_STRICT_CHECKS
slave_i2c_error:
reply_error(STATUS_I2C_ERROR);
return;
#endif
}
// Receive a frame from an address
// Slave must respect the i2c_ryder protocol : first byte tells if there are
// data to transmit or not
// Return number of read bytes
uint8_t i2cm_rcv(uint8_t slave_addr, uint8_t n, uint8_t* data)
{
int i;
I2C_START();
// Slave address + Read bit (1)
I2C_SEND((slave_addr<<1)+1);
// No ACK, no data
if( TW_STATUS != TW_MR_SLA_ACK )
{
I2C_STOP();
wait_4cyc(100);
return 0;
}
// First byte: is there something to transmit?
I2C_ACK();
if( TWDR == 0 )
{
I2C_NACK();
I2C_STOP();
wait_4cyc(100);
return 0;
}
// Read all data
for( i=0; i<n; i++ )
{
I2C_ACK();
data[i] = TWDR;
}
I2C_NACK();
I2C_STOP();
wait_4cyc(100);
return 1;
}
void i2cs_init(uint8_t slave_addr)
{
unsigned int i;
for( i=0; i<sizeof(i2cs_recv_buf); i++ )
i2cs_recv_buf[i] = 0;
i2cs_recv_size = 0;
for( i=0; i<sizeof(i2cs_send_buf); i++ )
i2cs_send_buf[i] = 0;
i2cs_send_size = 0;
TWAR = slave_addr << 1;
I2C_ACK();
}
unsigned long DS1672_Value(void)
{
unsigned long value;
int t;
unsigned long v;
I2C_Init(100,1000000);
I2C_Start();
t=I2C_TX(0xD1);
if(t!=0) return 0xffffffff;
t=I2C_RX();
if(t==-1) return 0xffffffff;
value=t;
I2C_ACK();
t=I2C_RX();
if(t==-1) return 0xffffffff;
v = t;
value+=v<<8;
I2C_ACK();
t=I2C_RX();
if(t==-1) return 0xffffffff;
v = t;
value+=v<<16;
I2C_ACK();
t=I2C_RX();
if(t==-1) return 0xffffffff;
v = t;
value+=v<<24;
I2C_NACK();
I2C_Stop();
return value;
}
// Receive one data byte from an address, -1 on error
int i2cm_rcv_single(uint8_t slave_addr)
{
I2C_START();
// Slave address + Read bit (1)
I2C_SEND((slave_addr<<1)+1);
// No ACK, no data
if( TW_STATUS != TW_MR_SLA_ACK )
{
I2C_STOP();
wait_4cyc(100);
return -1;
}
// First byte: is there something to transmit?
I2C_ACK();
return TWDR;
}
static void I2C_SEND(uint8_t d) { TWDR = (d); I2C_ACK(); }
