Hal_I2C.cpp File Reference

This file contains apis related to i2c. More...

#include "Platform.h"
#include <Wire.h>
#include "Hal_I2C.h"

Go to the source code of this file.

Functions
int16_t	hal_rtc_i2c_init ()
int16_t	hal_rtc_i2c_read (uint8_t addr, uint8_t *buffer, uint16_t length)
int16_t	hal_rtc_i2c_write (uint8_t addr, uint8_t *buffer, uint16_t length)

Detailed Description

This file contains apis related to i2c.

Author

Bridgetek

Date

2018

MIT License

Copyright (c) [2019] [Bridgetek Pte Ltd (BRTChip)]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Definition in file Hal_I2C.cpp.

Function Documentation

hal_rtc_i2c_init()

int16_t hal_rtc_i2c_init

(

)

Definition at line 39 of file Hal_I2C.cpp.

{
  Wire.begin();
  delay(100);  
  return 0;
}

hal_rtc_i2c_read()

int16_t hal_rtc_i2c_read	(	uint8_t	addr,
		uint8_t *	buffer,
		uint16_t	length
	)

Definition at line 47 of file Hal_I2C.cpp.

{
  uint16_t i;
  short count = 0;
  uint8_t writeResult = 0;
   while (length > 28)
  {
    hal_rtc_i2c_read(addr,buffer,28);
    buffer += 28;
    addr += 28;
    length -= 28;
  }
  
  Wire.beginTransmission(0x6f); // transmit to device (0x23)
  
 /* address bytes for rtc are from 00 to 0xff */
  Wire.write(addr);        // sends value byte  
  
  /* end the transmission but do not release the bus - usage is random data read use case from rtc */
  writeResult = Wire.endTransmission(false);//hold the bus to read the next data
 
  if (0 != writeResult)
  {
    return -1;//error case
  }
 
  Wire.requestFrom(0x6f, length);// request length bytes from slave device and end the transmission after this
  for(i=0;i<length;i++)
  {
    /* need to consider timout here */
    while(0 == Wire.available());//blocking call - at least one byte must be available
    buffer[i] = Wire.read();
  }
  
  return 0;
}

hal_rtc_i2c_write()

int16_t hal_rtc_i2c_write	(	uint8_t	addr,
		uint8_t *	buffer,
		uint16_t	length
	)

Definition at line 85 of file Hal_I2C.cpp.

{
  uint16_t i;
  byte writeResult = 0;
  if(0 == length)
  {
    return -1;
  }
  
  /* for read the lower bit must be set to 1 and for write set to 0 */
  Wire.beginTransmission(0x6f);
 
  /* address bytes for rtc are from 00 to 0xff */
  Wire.write(addr);        // sends value byte  
  
  /* check for each byte */
  for(i=0;i<length;i++)
  {
    Wire.write(*buffer++);//send the data to slave
  }
 
  /* end the transmission by stop bit */
  
  writeResult = Wire.endTransmission();//end the transmission by setting the stop bit
  
  if(0 != writeResult)
  {
    return writeResult;
  }
  return 0;
}