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Revision 891

Added by Brian Coltin over 15 years ago

Moved comments to headers. That was painful.

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i2c.h
32 32 
 *  @author Kevin Woo and Suresh Nidhiry, Colony Project, CMU Robotics Club
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 **/
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/**


  		




  
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 * @defgroup i2c I2C 


  		




  
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 *


  		




  
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 * @brief Provides Inter-Interconnected-Communications (I2C)


  		




  
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 * 


  		




  
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 * Initiates I2C functions on an ATMega128 which has a fully hardware Two Wire 


  		




  
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 * Interface (TWI) module. Any Atmel chip with this hardware should be able to


  		




  
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 * use the software.


  		




  
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 *


  		




  
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 * This code will operate in a multi-master enviornment and can be either a


  		




  
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 * slave or a master at any time (as long as they are not one or the other at


  		




  
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 * the moment. You can queue up multiple transmission modes in the buffer up to 


  		




  
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 * the buffer size. The buffer is implemented as a ring buffer.


  		




  
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 *


  		




  
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 * It is implemented using callback functions. Whenever you want to send a packet


  		




  
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 * you can call the built in send function (as a master) and it will send an array


  		




  
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 * of bytes. Master recieve and slave send/receive are all handled by the call back


  		




  
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 * functions. It is up to the end user to create functions that will handle the


  		




  
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 * receiving of packets. Their functions will be called with every byte recieved


  		




  
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 * so you must either buffer the inputs or handle each one separately.


  		




  
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 *


  		




  
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 * On errors we will simply flush the entire buffer.


  		




  
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 * 


  		




  
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 * For information on how I2C operates, read the wikipedia article


  		




  
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 * http://en.wikipedia.org/wiki/I2c


  		




  
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 * for a good explanation of how it works.


  		




  
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 * @{


  		




  
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 */


  		




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#ifndef _I2C_H_


  		




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#define _I2C_H_


  		




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/** @brief Address of slave send handler function**/


  		




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typedef char (*fun_send_t)(void);


  		




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/**


  		




  
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 * @brief Initializes the i2c module.


  		




  
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 *


  		




  
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 * Initializes the I2C module to start listening on the i2c lines. If the callback functions


  		




  
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 * are not set to null they will be called when that transmission mode is called. The address


  		




  
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 * is your address that you will listen to when you are not the master.


  		




  
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 *


  		




  
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 * @param addr 			Your address on the I2C bus.


  		




  
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 * @param master_recv 	The address of the function to call when you receive a byte when you are a


  		




  
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 *                    	master.


  		




  
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 * @param slave_recv 	The address of the function to call when you are a slave you receive data


  		




  
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 *								from the master


  		




  
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 * @param slave_send		The address of the function to call when you are a slave and the master


  		




  
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 *								requests data from you.


  		




  
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 *


  		




  
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 * @return 0 for success, nonzero for failure


  		




  
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 **/


  		




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int i2c_init(char addr, fun_mrecv_t master_recv, fun_srecv_t slave_recv, fun_send_t slave_send);


  		




  
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/**


  		




  
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 * @brief Sends a byte array over I2C as a master


  		




  
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 *


  		




  
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 * Will perform a send over I2C to the destination from data for the ammount of


  		




  
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 * bytes that bytes is.


  		




  
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 *


  		




  
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 * @param dest		Destination address of the data on the I2C bus.


  		




  
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 * @param data 	The pointer to the byte array of data


  		




  
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 * @param bytes	The amount of bytes long that the byte array is. This is how


  		




  
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 *						many bytes from the array that the function will send.


  		




  
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 *


  		




  
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 * @return zero for success, nonzero for failure


  		




  
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 **/


  		




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int i2c_send(char dest, char* data, size_t bytes);


  		




  
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/**


  		




  
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 * @brief Send a master request to the destination


  		




  
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 *


  		




  
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 * Sends a request of data from the target address and calls


  		




  
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 * the callback function to handle data as it comes in. This function will


  		




  
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 * not work if the slave has not informationt to send or has nothing implemented


  		




  
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 * to send it.


  		




  
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 *


  		




  
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 * @param dest		The destination that we want to receive information from.


  		




  
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 *


  		




  
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 * @return 0 for success, nonzero for failure


  		




  
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 **/ 


  		




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int i2c_request(char dest);


  		




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void i2c_packet_rec (char i2c_byte);


  		




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void i2c_packet_sniff(char data);


  		




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#endif


  		




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