Changeset - 96a7529926a0
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kripperger@CL-SEC241-09.cedarville.edu - 12 years ago 2012-11-07 22:08:56
kripperger@CL-SEC241-09.cedarville.edu
i2c library work.
4 files changed with 251 insertions and 0 deletions:
slave/slave/lib/i2c.c
198
slave/slave/lib/i2c.h
49
slave/slave/lib/led.c
1
slave/slave/slave.c
3
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slave/slave/lib/i2c.c
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/*
 
 * i2c.c
 
 *
 
 * Created: 11/7/2012 7:18:23 PM
 
 *  Author: kripperger
 
 */
 
 
#include <inttypes.h>
 
#include <compat/twi.h>
 
#include "../config.h"
 
#include "i2c.h"
 
 
 
/* I2C clock in Hz */
 
#define SCL_CLOCK  100000L
 
 
 
 
/*************************************************************************
 
 Initialization of the I2C bus interface. Need to be called only once
 
*************************************************************************/
 
void i2c_init(void)
 
{
 
  /* initialize TWI clock: 100 kHz clock, TWPS = 0 => prescaler = 1 */
 
 
  TWSR = 0;                         /* no prescaler */
 
  TWBR = ((F_CPU/SCL_CLOCK)-16)/2;  /* must be > 10 for stable operation */
 
 
}/* i2c_init */
 
 
 
 
/*************************************************************************
 
  Issues a start condition and sends address and transfer direction.
 
  return 0 = device accessible, 1= failed to access device
 
*************************************************************************/
 
unsigned char i2c_start(unsigned char address)
 
{
 
    uint8_t   twst;
 
 
	// send START condition
 
	TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
 
 
	// wait until transmission completed
 
	while(!(TWCR & (1<<TWINT)));
 
 
	// check value of TWI Status Register. Mask prescaler bits.
 
	twst = TW_STATUS & 0xF8;
 
	if ( (twst != TW_START) && (twst != TW_REP_START)) return 1;
 
 
	// send device address
 
	TWDR = address;
 
	TWCR = (1<<TWINT) | (1<<TWEN);
 
 
	// wail until transmission completed and ACK/NACK has been received
 
	while(!(TWCR & (1<<TWINT)));
 
 
	// check value of TWI Status Register. Mask prescaler bits.
 
	twst = TW_STATUS & 0xF8;
 
	if ( (twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK) ) return 1;
 
 
	return 0;
 
 
}/* i2c_start */
 
 
 
 
/*************************************************************************
 
 Issues a start condition and sends address and transfer direction.
 
 If device is busy, use ack polling to wait until device is ready
 
 
 Input:   address and transfer direction of I2C device
 
*************************************************************************/
 
void i2c_start_wait(unsigned char address)
 
{
 
    uint8_t   twst;
 
 
 
    while ( 1 )
 
    {
 
	    // send START condition
 
	    TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
 
 
    	// wait until transmission completed
 
    	while(!(TWCR & (1<<TWINT)));
 
 
    	// check value of TWI Status Register. Mask prescaler bits.
 
    	twst = TW_STATUS & 0xF8;
 
    	if ( (twst != TW_START) && (twst != TW_REP_START)) continue;
 
 
    	// send device address
 
    	TWDR = address;
 
    	TWCR = (1<<TWINT) | (1<<TWEN);
 
 
    	// wail until transmission completed
 
    	while(!(TWCR & (1<<TWINT)));
 
 
    	// check value of TWI Status Register. Mask prescaler bits.
 
    	twst = TW_STATUS & 0xF8;
 
    	if ( (twst == TW_MT_SLA_NACK )||(twst ==TW_MR_DATA_NACK) )
 
    	{
 
    	    /* device busy, send stop condition to terminate write operation */
 
	        TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
 
 
	        // wait until stop condition is executed and bus released
 
	        while(TWCR & (1<<TWSTO));
 
 
    	    continue;
 
    	}
 
    	//if( twst != TW_MT_SLA_ACK) return 1;
 
    	break;
 
     }
 
 
}/* i2c_start_wait */
 
 
 
 
/*************************************************************************
 
 Issues a repeated start condition and sends address and transfer direction
 
 
 Input:   address and transfer direction of I2C device
 
 
 Return:  0 device accessible
 
          1 failed to access device
 
*************************************************************************/
 
unsigned char i2c_rep_start(unsigned char address)
 
{
 
    return i2c_start( address );
 
 
}/* i2c_rep_start */
 
 
 
 
/*************************************************************************
 
 Terminates the data transfer and releases the I2C bus
 
*************************************************************************/
 
void i2c_stop(void)
 
{
 
    /* send stop condition */
 
	TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
 
 
	// wait until stop condition is executed and bus released
 
	while(TWCR & (1<<TWSTO));
 
 
}/* i2c_stop */
 
 
 
 
/*************************************************************************
 
  Send one byte to I2C device
 
 
  Input:    byte to be transfered
 
  Return:   0 write successful
 
            1 write failed
 
*************************************************************************/
 
unsigned char i2c_write( unsigned char data )
 
{
 
    uint8_t   twst;
 
 
	// send data to the previously addressed device
 
	TWDR = data;
 
	TWCR = (1<<TWINT) | (1<<TWEN);
 
 
	// wait until transmission completed
 
	while(!(TWCR & (1<<TWINT)));
 
 
	// check value of TWI Status Register. Mask prescaler bits
 
	twst = TW_STATUS & 0xF8;
 
	if( twst != TW_MT_DATA_ACK) return 1;
 
	return 0;
 
 
}/* i2c_write */
 
 
 
 
/*************************************************************************
 
 Read one byte from the I2C device, request more data from device
 
 
 Return:  byte read from I2C device
 
*************************************************************************/
 
unsigned char i2c_readAck(void)
 
{
 
	TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA);
 
	while(!(TWCR & (1<<TWINT)));
 
 
    return TWDR;
 
 
}/* i2c_readAck */
 
 
 
 
/*************************************************************************
 
 Read one byte from the I2C device, read is followed by a stop condition
 
 
 Return:  byte read from I2C device
 
*************************************************************************/
 
unsigned char i2c_readNak(void)
 
{
 
	TWCR = (1<<TWINT) | (1<<TWEN);
 
	while(!(TWCR & (1<<TWINT)));
 
 
    return TWDR;
 
 
}/* i2c_readNak */
slave/slave/lib/i2c.h
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/*
 
 * i2c.h
 
 *
 
 * Created: 11/7/2012 7:18:33 PM
 
 *  Author: kripperger
 
 */
 
 
 
#ifndef I2C_H_
 
#define I2C_H_
 
 
 
#if (__GNUC__ * 100 + __GNUC_MINOR__) < 304
 
#error "This library requires AVR-GCC 3.4 or later, update to newer AVR-GCC compiler !"
 
#endif
 
 
 
#include <avr/io.h>
 
 
 
/** defines the data direction (reading from I2C device) in i2c_start(),i2c_rep_start() */
 
#define I2C_READ    1
 
 
/** defines the data direction (writing to I2C device) in i2c_start(),i2c_rep_start() */
 
#define I2C_WRITE   0
 
 
 
 
void i2c_init(void);	//initialize the I2C master interace. Need to be called only once
 
 
void i2c_stop(void);	//Terminates the data transfer and releases the I2C bus
 
 
unsigned char i2c_start(unsigned char addr);	//Issues a start condition and sends address and transfer direction
 
	//addr is the address and transfer direction of I2C device
 
	//Returns   0   device accessible
 
	//Returns   1   failed to access device
 
 
unsigned char i2c_rep_start(unsigned char addr);	//Issues a repeated start condition and sends address and transfer direction
 
	//addr is the address and transfer direction of I2C device
 
	//Returns   0   device accessible
 
	//Returns   1   failed to access device
 
 
void i2c_start_wait(unsigned char addr);	//Issues a start condition and sends address and transfer direction. If device is busy, use ack polling to wait until device ready
 
	//addr is the address and transfer direction of I2C device
 
 
unsigned char i2c_write(unsigned char data);	//Send one byte to I2C device
 
	//data is the byte to be transfered
 
	//Returns   0   write successful
 
	//Returns   1   write failed
 
 
unsigned char i2c_readAck(void);	//read one byte from the I2C device, request more data from device
 
	//Returns byte read from I2C device
 
 
unsigned char i2c_readNak(void);	//read one byte from the I2C device, read is followed by a stop condition
 
	//Returns byte read from I2C device
 
 
unsigned char i2c_read(unsigned char ack);	//read one byte from the I2C device. Implemented as a macro, which calls either i2c_readAck or i2c_readNak
 
#define i2c_read(ack)  (ack) ? i2c_readAck() : i2c_readNak();
 
	//When ack is 1: send ack, request more data from device
 
	//When ack is 0: send nak, read is followed by a stop condition
 
	//Returns byte read from I2C device
 
 
 
 
#endif /* I2C_H_ */
 
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slave/slave/lib/led.c
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/*
 
 * led.c
 
 *
 
 * Created: 10/25/2012 10:03:22 PM
 
 *  Author: mkanning
 
 */
 
 
 #include <avr/io.h>
 
 #include "led.h"
 
 
 void led_configure()
 
 {
 
	 // Configure ports/pins for LEDs
 
 
 }
 
 
 void led_on(uint8_t led)
 
 {
 
	 // Turn the specified LED on
 
 
 }
 
 
 void led_off(uint8_t led)
 
 {
 
	 // Turn the specified LED off
 
 
 }
 
 
 void led_toggle(uint8_t led)
 
 {
 
	 // Toggle the specified LED
 
 
 }
 
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slave/slave/slave.c
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/*
 
 * Slave Firmware
 
 *
 
 * Wireless Observational Modular Aerial Network
 
 *
 
 * Ethan Zonca
 
 * Matthew Kanning
 
 * Kyle Ripperger
 
 * Matthew Kroening
 
 *
 
 */
 
 
 
#include "config.h"
 
 
#include <inttypes.h>
 
#include <avr/io.h>
 
#include <util/delay.h>
 
#include <compat/twi.h>
 
 
//#include "lib/serial.h"
 
#include "lib/led.h"
 
#include "lib/inputOutput.h"
 
#include "lib/i2c.h"
 
 
 
void micro_setup()
 
{
 
	// Generic microcontroller config options
 
 
}
 
 
 
 
int main(void)
 
{
 
	// Initialize
 
	micro_setup();
 
	led_configure();
 
	//serial_setup(); // Config serial ports
 
	uint8_t moduleID = io_getModuleId(); //Slave Module ID from rotary dip switch
 
 
 
 
    while(1)
 
    {
 
 
        //serial_SendCommand('0','A',0,0);
 
 
 
    }
 
 
	return 0;
 
}
 
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