char e_i2cp_read_string(char device_add, char *read_buffer, char start_address, char string_length)
{
char error=0;
error=1;
error&=e_i2c_start();
error&=e_i2c_write(device_add); // Device address
error&=e_i2c_write(start_address); // address of first register to be read
error&=e_i2c_restart();
error&=e_i2c_write(device_add+1); // To change data direction ([bit 0]=1)
while (string_length) {
error&=e_i2c_read(read_buffer); // read a single byte
read_buffer++;
string_length--;
if(string_length == 0) { /* If last char, generate NACK sequence */
error&=e_i2c_nack(); // the last byte to be read, must send nack
} else { /* For other chars,generate ACK sequence */
error&=e_i2c_ack();
}
while(I2C1CONbits.ACKEN == 1); /* Wait till ACK/NACK sequence is over */
}
e_i2c_stop(); // End read cycle
return error;
}
/*!\brief Continuous read (multiple register reading).
* \param device_add The device address
* \param read_buffer the buffer that will contain the values read from the registers
* \param reg The register start address
* \return 1 to confirme the oparation and 0 for an error
*/
char readRegMulti(char device_add, unsigned char *read_buffer, char start_address, unsigned char numBytes) {
char error = 0;
unsigned int i = 0;
while (!error) {
error = 1;
error &= e_i2c_start();
error &= e_i2c_write(device_add); // Device address
error &= e_i2c_write(start_address | 0x80); // address of first register to be read
error &= e_i2c_restart();
error &= e_i2c_write(device_add + 1); // To change data direction ([bit 0]=1)
for (i = 0; i < numBytes; i++) {
error &= e_i2c_read(&read_buffer[i]); // read the next byte
if (i == (numBytes - 1)) { // the last byte to be read, must send nack
error &= e_i2c_nack();
} else {
error &= e_i2c_ack(); // not the last byte, send ack
}
}
e_i2c_stop(); // End read cycle
if (error)
break;
e_i2c_reset();
}
return error;
}
//read 1 byte from the register reg of devantec sensor
char e_i2cd_readb(char device_add, char reg)
{
char value;
e_i2c_start(); // start
e_i2c_write(device_add); // Device address
e_i2c_write(reg); // Register address
e_i2c_restart(); // 2nd start
e_i2c_write(device_add+1); // Device address
e_i2c_read(&value); // read single byte
e_i2c_nack(); // only 1 byte is being read, so send nack
e_i2c_stop(); // end read cycle
e_i2c_reset();
return value;
}
char read_ext_eeprom(unsigned short address)
{
char error=0; // Initialize to no error
char data=0x00; // Initialize the data
while(!error) { // While they are still some errors...
error=1; // We initilize the error to 1
//while(!ext_eeprom_ready()); // Proposed in 2432.c from PICC, not very useful here
error&=e_i2c_start(); // We intiate a start and...
error&=e_i2c_write(0x10); // ... write the hardware selectable address A0 = 0, A1 = 1, A2 = 0 and we write (last bit = 0)
error&=e_i2c_write(0x01); // ... then the least significant byte of the memory address
error&=e_i2c_restart(); // ... In order to indicate to the slave that he can send the data, we iniate a restart
error&=e_i2c_write(0x11); // ... write the hardware selectable address A0 = 0, A1 = 1, A2 = 0 and we read (last bit = 1)
error&=e_i2c_read(&data); // ... and read the data sent by the slave (here the memory)
error&=e_i2c_nack(); // ... only 1 byte is being read, so send nack
error&=e_i2c_stop(); // ... the tranfer is then terminated by a stop
}
return(data);
}
char e_i2cp_read(char device_add,char reg)
{
char error=0; // Initialize to no error
char value; // Value that will be returned
while(!error) { // While they are still some errors...
error=1; // We initilize the error to 1
error&=e_i2c_start(); // We intiate a start and...
error&=e_i2c_write(device_add); // ... write the I2C MODULE ADDRESS we want to read
error&=e_i2c_write(reg); // ... and the REGISTER ADDRESS we want to read
error&=e_i2c_restart(); // ... In order to indicate to the slave that he can send the data, we iniate a restart
error&=e_i2c_write(device_add+1); // ... and rewrite the MODULE ADDRESS with change of data direction ([bit 0]=1)
error&=e_i2c_read(&value); // ... and read the data sent by the slave (the I2C Module)
e_i2c_nack(); // ... only 1 byte is being read, so send nack
e_i2c_stop(); // ... the tranfer is then terminated by a stop
if(error) {
break;
}
e_i2c_reset();
}
return value;
}
/*! \brief Read a specific register on a device
* \param device_add The address of the device you want information
* \param reg The register address you want read on the device
* \return The readed value
*/
char e_i2cp_read(char device_add, char reg)
{
char error=0;
char value;
while(!error)
{
error=1;
error&=e_i2c_start();
error&=e_i2c_write(device_add); // Device address
error&=e_i2c_write(reg); // Register address
error&=e_i2c_restart();
error&=e_i2c_write(device_add+1); // To change data direction ([bit 0]=1)
error&=e_i2c_read(&value); // read single byte
e_i2c_nack(); // only 1 byte is being read, so send nack
e_i2c_stop(); // end read cycle
if(error)
break;
e_i2c_reset();
}
return value;
}
