forked from forks/qmk_firmware
Merge remote-tracking branch 'origin/master' into develop
This commit is contained in:
commit
f6b0484f0f
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@ -1,5 +1,4 @@
|
||||||
#include "dactyl.h"
|
#include "dactyl.h"
|
||||||
#include "i2cmaster.h"
|
|
||||||
|
|
||||||
#ifdef SWAP_HANDS_ENABLE
|
#ifdef SWAP_HANDS_ENABLE
|
||||||
__attribute__ ((weak))
|
__attribute__ ((weak))
|
||||||
|
|
|
@ -3,12 +3,11 @@
|
||||||
#include "quantum.h"
|
#include "quantum.h"
|
||||||
#include <stdint.h>
|
#include <stdint.h>
|
||||||
#include <stdbool.h>
|
#include <stdbool.h>
|
||||||
#include "i2cmaster.h"
|
#include "i2c_master.h"
|
||||||
#include <util/delay.h>
|
#include <util/delay.h>
|
||||||
|
|
||||||
#define I2C_ADDR 0b0100000
|
#define I2C_ADDR 0b0100000
|
||||||
#define I2C_ADDR_WRITE ( (I2C_ADDR<<1) | I2C_WRITE )
|
#define I2C_TIMEOUT 100
|
||||||
#define I2C_ADDR_READ ( (I2C_ADDR<<1) | I2C_READ )
|
|
||||||
#define IODIRA 0x00 // i/o direction register
|
#define IODIRA 0x00 // i/o direction register
|
||||||
#define IODIRB 0x01
|
#define IODIRB 0x01
|
||||||
#define GPPUA 0x0C // GPIO pull-up resistor register
|
#define GPPUA 0x0C // GPIO pull-up resistor register
|
||||||
|
|
|
@ -1,178 +0,0 @@
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#ifndef _I2CMASTER_H
|
|
||||||
#define _I2CMASTER_H 1
|
|
||||||
/*************************************************************************
|
|
||||||
* Title: C include file for the I2C master interface
|
|
||||||
* (i2cmaster.S or twimaster.c)
|
|
||||||
* Author: Peter Fleury <pfleury@gmx.ch> http://jump.to/fleury
|
|
||||||
* File: $Id: i2cmaster.h,v 1.10 2005/03/06 22:39:57 Peter Exp $
|
|
||||||
* Software: AVR-GCC 3.4.3 / avr-libc 1.2.3
|
|
||||||
* Target: any AVR device
|
|
||||||
* Usage: see Doxygen manual
|
|
||||||
**************************************************************************/
|
|
||||||
|
|
||||||
#ifdef DOXYGEN
|
|
||||||
/**
|
|
||||||
@defgroup pfleury_ic2master I2C Master library
|
|
||||||
@code #include <i2cmaster.h> @endcode
|
|
||||||
|
|
||||||
@brief I2C (TWI) Master Software Library
|
|
||||||
|
|
||||||
Basic routines for communicating with I2C slave devices. This single master
|
|
||||||
implementation is limited to one bus master on the I2C bus.
|
|
||||||
|
|
||||||
This I2c library is implemented as a compact assembler software implementation of the I2C protocol
|
|
||||||
which runs on any AVR (i2cmaster.S) and as a TWI hardware interface for all AVR with built-in TWI hardware (twimaster.c).
|
|
||||||
Since the API for these two implementations is exactly the same, an application can be linked either against the
|
|
||||||
software I2C implementation or the hardware I2C implementation.
|
|
||||||
|
|
||||||
Use 4.7k pull-up resistor on the SDA and SCL pin.
|
|
||||||
|
|
||||||
Adapt the SCL and SDA port and pin definitions and eventually the delay routine in the module
|
|
||||||
i2cmaster.S to your target when using the software I2C implementation !
|
|
||||||
|
|
||||||
Adjust the CPU clock frequence F_CPU in twimaster.c or in the Makfile when using the TWI hardware implementaion.
|
|
||||||
|
|
||||||
@note
|
|
||||||
The module i2cmaster.S is based on the Atmel Application Note AVR300, corrected and adapted
|
|
||||||
to GNU assembler and AVR-GCC C call interface.
|
|
||||||
Replaced the incorrect quarter period delays found in AVR300 with
|
|
||||||
half period delays.
|
|
||||||
|
|
||||||
@author Peter Fleury pfleury@gmx.ch http://jump.to/fleury
|
|
||||||
|
|
||||||
@par API Usage Example
|
|
||||||
The following code shows typical usage of this library, see example test_i2cmaster.c
|
|
||||||
|
|
||||||
@code
|
|
||||||
|
|
||||||
#include <i2cmaster.h>
|
|
||||||
|
|
||||||
|
|
||||||
#define Dev24C02 0xA2 // device address of EEPROM 24C02, see datasheet
|
|
||||||
|
|
||||||
int main(void)
|
|
||||||
{
|
|
||||||
unsigned char ret;
|
|
||||||
|
|
||||||
i2c_init(); // initialize I2C library
|
|
||||||
|
|
||||||
// write 0x75 to EEPROM address 5 (Byte Write)
|
|
||||||
i2c_start_wait(Dev24C02+I2C_WRITE); // set device address and write mode
|
|
||||||
i2c_write(0x05); // write address = 5
|
|
||||||
i2c_write(0x75); // write value 0x75 to EEPROM
|
|
||||||
i2c_stop(); // set stop conditon = release bus
|
|
||||||
|
|
||||||
|
|
||||||
// read previously written value back from EEPROM address 5
|
|
||||||
i2c_start_wait(Dev24C02+I2C_WRITE); // set device address and write mode
|
|
||||||
|
|
||||||
i2c_write(0x05); // write address = 5
|
|
||||||
i2c_rep_start(Dev24C02+I2C_READ); // set device address and read mode
|
|
||||||
|
|
||||||
ret = i2c_readNak(); // read one byte from EEPROM
|
|
||||||
i2c_stop();
|
|
||||||
|
|
||||||
for(;;);
|
|
||||||
}
|
|
||||||
@endcode
|
|
||||||
|
|
||||||
*/
|
|
||||||
#endif /* DOXYGEN */
|
|
||||||
|
|
||||||
/**@{*/
|
|
||||||
|
|
||||||
#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
|
|
||||||
|
|
||||||
|
|
||||||
/**
|
|
||||||
@brief initialize the I2C master interace. Need to be called only once
|
|
||||||
@param void
|
|
||||||
@return none
|
|
||||||
*/
|
|
||||||
extern void i2c_init(void);
|
|
||||||
|
|
||||||
|
|
||||||
/**
|
|
||||||
@brief Terminates the data transfer and releases the I2C bus
|
|
||||||
@param void
|
|
||||||
@return none
|
|
||||||
*/
|
|
||||||
extern void i2c_stop(void);
|
|
||||||
|
|
||||||
|
|
||||||
/**
|
|
||||||
@brief Issues a start condition and sends address and transfer direction
|
|
||||||
|
|
||||||
@param addr address and transfer direction of I2C device
|
|
||||||
@retval 0 device accessible
|
|
||||||
@retval 1 failed to access device
|
|
||||||
*/
|
|
||||||
extern unsigned char i2c_start(unsigned char addr);
|
|
||||||
|
|
||||||
|
|
||||||
/**
|
|
||||||
@brief Issues a repeated start condition and sends address and transfer direction
|
|
||||||
|
|
||||||
@param addr address and transfer direction of I2C device
|
|
||||||
@retval 0 device accessible
|
|
||||||
@retval 1 failed to access device
|
|
||||||
*/
|
|
||||||
extern unsigned char i2c_rep_start(unsigned char addr);
|
|
||||||
|
|
||||||
|
|
||||||
/**
|
|
||||||
@brief Issues a start condition and sends address and transfer direction
|
|
||||||
|
|
||||||
If device is busy, use ack polling to wait until device ready
|
|
||||||
@param addr address and transfer direction of I2C device
|
|
||||||
@return none
|
|
||||||
*/
|
|
||||||
extern void i2c_start_wait(unsigned char addr);
|
|
||||||
|
|
||||||
|
|
||||||
/**
|
|
||||||
@brief Send one byte to I2C device
|
|
||||||
@param data byte to be transfered
|
|
||||||
@retval 0 write successful
|
|
||||||
@retval 1 write failed
|
|
||||||
*/
|
|
||||||
extern unsigned char i2c_write(unsigned char data);
|
|
||||||
|
|
||||||
|
|
||||||
/**
|
|
||||||
@brief read one byte from the I2C device, request more data from device
|
|
||||||
@return byte read from I2C device
|
|
||||||
*/
|
|
||||||
extern unsigned char i2c_readAck(void);
|
|
||||||
|
|
||||||
/**
|
|
||||||
@brief read one byte from the I2C device, read is followed by a stop condition
|
|
||||||
@return byte read from I2C device
|
|
||||||
*/
|
|
||||||
extern unsigned char i2c_readNak(void);
|
|
||||||
|
|
||||||
/**
|
|
||||||
@brief read one byte from the I2C device
|
|
||||||
|
|
||||||
Implemented as a macro, which calls either i2c_readAck or i2c_readNak
|
|
||||||
|
|
||||||
@param ack 1 send ack, request more data from device<br>
|
|
||||||
0 send nak, read is followed by a stop condition
|
|
||||||
@return byte read from I2C device
|
|
||||||
*/
|
|
||||||
extern unsigned char i2c_read(unsigned char ack);
|
|
||||||
#define i2c_read(ack) (ack) ? i2c_readAck() : i2c_readNak();
|
|
||||||
|
|
||||||
|
|
||||||
/**@}*/
|
|
||||||
#endif
|
|
|
@ -25,7 +25,7 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||||
#include "util.h"
|
#include "util.h"
|
||||||
#include "matrix.h"
|
#include "matrix.h"
|
||||||
#include "dactyl.h"
|
#include "dactyl.h"
|
||||||
#include "i2cmaster.h"
|
#include "i2c_master.h"
|
||||||
#include "timer.h"
|
#include "timer.h"
|
||||||
|
|
||||||
|
|
||||||
|
@ -147,9 +147,6 @@ void init_expander(void) {
|
||||||
#endif
|
#endif
|
||||||
}
|
}
|
||||||
|
|
||||||
expander_status = i2c_start(I2C_ADDR_WRITE); if (expander_status) goto out;
|
|
||||||
expander_status = i2c_write(IODIRA); if (expander_status) goto out;
|
|
||||||
|
|
||||||
/*
|
/*
|
||||||
Pin direction and pull-up depends on both the diode direction
|
Pin direction and pull-up depends on both the diode direction
|
||||||
and on whether the column register is GPIOA or GPIOB
|
and on whether the column register is GPIOA or GPIOB
|
||||||
|
@ -164,50 +161,65 @@ void init_expander(void) {
|
||||||
|
|
||||||
#if (EXPANDER_COL_REGISTER == GPIOA)
|
#if (EXPANDER_COL_REGISTER == GPIOA)
|
||||||
# if (DIODE_DIRECTION == COL2ROW)
|
# if (DIODE_DIRECTION == COL2ROW)
|
||||||
expander_status = i2c_write(expander_input_pin_mask); if (expander_status) goto out;
|
uint8_t direction[2] = {
|
||||||
expander_status = i2c_write(0); if (expander_status) goto out;
|
expander_input_pin_mask,
|
||||||
|
0,
|
||||||
|
};
|
||||||
# elif (DIODE_DIRECTION == ROW2COL)
|
# elif (DIODE_DIRECTION == ROW2COL)
|
||||||
expander_status = i2c_write(0); if (expander_status) goto out;
|
uint8_t direction[2] = {
|
||||||
expander_status = i2c_write(expander_input_pin_mask); if (expander_status) goto out;
|
0,
|
||||||
|
expander_input_pin_mask,
|
||||||
|
};
|
||||||
# endif
|
# endif
|
||||||
#elif (EXPANDER_COL_REGISTER == GPIOB)
|
#elif (EXPANDER_COL_REGISTER == GPIOB)
|
||||||
# if (DIODE_DIRECTION == COL2ROW)
|
# if (DIODE_DIRECTION == COL2ROW)
|
||||||
expander_status = i2c_write(0); if (expander_status) goto out;
|
uint8_t direction[2] = {
|
||||||
expander_status = i2c_write(expander_input_pin_mask); if (expander_status) goto out;
|
0,
|
||||||
|
expander_input_pin_mask,
|
||||||
|
};
|
||||||
# elif (DIODE_DIRECTION == ROW2COL)
|
# elif (DIODE_DIRECTION == ROW2COL)
|
||||||
expander_status = i2c_write(expander_input_pin_mask); if (expander_status) goto out;
|
uint8_t direction[2] = {
|
||||||
expander_status = i2c_write(0); if (expander_status) goto out;
|
expander_input_pin_mask,
|
||||||
|
0,
|
||||||
|
};
|
||||||
# endif
|
# endif
|
||||||
#endif
|
#endif
|
||||||
|
|
||||||
i2c_stop();
|
|
||||||
|
|
||||||
// set pull-up
|
// set pull-up
|
||||||
// - unused : off : 0
|
// - unused : off : 0
|
||||||
// - input : on : 1
|
// - input : on : 1
|
||||||
// - driving : off : 0
|
// - driving : off : 0
|
||||||
expander_status = i2c_start(I2C_ADDR_WRITE); if (expander_status) goto out;
|
|
||||||
expander_status = i2c_write(GPPUA); if (expander_status) goto out;
|
|
||||||
#if (EXPANDER_COL_REGISTER == GPIOA)
|
#if (EXPANDER_COL_REGISTER == GPIOA)
|
||||||
# if (DIODE_DIRECTION == COL2ROW)
|
# if (DIODE_DIRECTION == COL2ROW)
|
||||||
expander_status = i2c_write(expander_input_pin_mask); if (expander_status) goto out;
|
uint8_t pullup[2] = {
|
||||||
expander_status = i2c_write(0); if (expander_status) goto out;
|
expander_input_pin_mask,
|
||||||
|
0,
|
||||||
|
};
|
||||||
# elif (DIODE_DIRECTION == ROW2COL)
|
# elif (DIODE_DIRECTION == ROW2COL)
|
||||||
expander_status = i2c_write(0); if (expander_status) goto out;
|
uint8_t pullup[2] = {
|
||||||
expander_status = i2c_write(expander_input_pin_mask); if (expander_status) goto out;
|
0,
|
||||||
|
expander_input_pin_mask,
|
||||||
|
};
|
||||||
# endif
|
# endif
|
||||||
#elif (EXPANDER_COL_REGISTER == GPIOB)
|
#elif (EXPANDER_COL_REGISTER == GPIOB)
|
||||||
# if (DIODE_DIRECTION == COL2ROW)
|
# if (DIODE_DIRECTION == COL2ROW)
|
||||||
expander_status = i2c_write(0); if (expander_status) goto out;
|
uint8_t pullup[2] = {
|
||||||
expander_status = i2c_write(expander_input_pin_mask); if (expander_status) goto out;
|
0,
|
||||||
|
expander_input_pin_mask,
|
||||||
|
};
|
||||||
# elif (DIODE_DIRECTION == ROW2COL)
|
# elif (DIODE_DIRECTION == ROW2COL)
|
||||||
expander_status = i2c_write(expander_input_pin_mask); if (expander_status) goto out;
|
uint8_t pullup[2] = {
|
||||||
expander_status = i2c_write(0); if (expander_status) goto out;
|
expander_input_pin_mask,
|
||||||
|
0,
|
||||||
|
};
|
||||||
# endif
|
# endif
|
||||||
#endif
|
#endif
|
||||||
|
|
||||||
out:
|
|
||||||
i2c_stop();
|
expander_status = i2c_writeReg(I2C_ADDR, IODIRA, direction, 2, I2C_TIMEOUT);
|
||||||
|
if (expander_status) return;
|
||||||
|
|
||||||
|
expander_status = i2c_writeReg(I2C_ADDR, GPPUA, pullup, 2, I2C_TIMEOUT);
|
||||||
}
|
}
|
||||||
|
|
||||||
uint8_t matrix_scan(void)
|
uint8_t matrix_scan(void)
|
||||||
|
@ -337,14 +349,11 @@ static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row)
|
||||||
|
|
||||||
// Read columns from expander, unless it's in an error state
|
// Read columns from expander, unless it's in an error state
|
||||||
if (! expander_status) {
|
if (! expander_status) {
|
||||||
expander_status = i2c_start(I2C_ADDR_WRITE); if (expander_status) goto out;
|
uint8_t state = 0;
|
||||||
expander_status = i2c_write(EXPANDER_COL_REGISTER); if (expander_status) goto out;
|
expander_status = i2c_readReg(I2C_ADDR, EXPANDER_COL_REGISTER, &state, 1, I2C_TIMEOUT);
|
||||||
expander_status = i2c_start(I2C_ADDR_READ); if (expander_status) goto out;
|
if (! expander_status) {
|
||||||
|
current_matrix[current_row] |= (~state) & expander_input_pin_mask;
|
||||||
current_matrix[current_row] |= (~i2c_readNak()) & expander_input_pin_mask;
|
}
|
||||||
|
|
||||||
out:
|
|
||||||
i2c_stop();
|
|
||||||
}
|
}
|
||||||
|
|
||||||
// Read columns from onboard pins
|
// Read columns from onboard pins
|
||||||
|
@ -366,11 +375,8 @@ static void select_row(uint8_t row) {
|
||||||
if (! expander_status) {
|
if (! expander_status) {
|
||||||
// set active row low : 0
|
// set active row low : 0
|
||||||
// set other rows hi-Z : 1
|
// set other rows hi-Z : 1
|
||||||
expander_status = i2c_start(I2C_ADDR_WRITE); if (expander_status) goto out;
|
uint8_t port = 0xFF & ~(1<<row);
|
||||||
expander_status = i2c_write(EXPANDER_ROW_REGISTER); if (expander_status) goto out;
|
expander_status = i2c_writeReg(I2C_ADDR, EXPANDER_ROW_REGISTER, &port, 1, I2C_TIMEOUT);
|
||||||
expander_status = i2c_write(0xFF & ~(1<<row)); if (expander_status) goto out;
|
|
||||||
out:
|
|
||||||
i2c_stop();
|
|
||||||
}
|
}
|
||||||
|
|
||||||
// select on teensy
|
// select on teensy
|
||||||
|
@ -426,13 +432,7 @@ static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col)
|
||||||
return false;
|
return false;
|
||||||
}
|
}
|
||||||
|
|
||||||
expander_status = i2c_start(I2C_ADDR_WRITE); if (expander_status) goto out;
|
expander_status = i2c_readReg(I2C_ADDR, EXPANDER_ROW_REGISTER, &column_state, 1, I2C_TIMEOUT);
|
||||||
expander_status = i2c_write(EXPANDER_ROW_REGISTER); if (expander_status) goto out;
|
|
||||||
expander_status = i2c_start(I2C_ADDR_READ); if (expander_status) goto out;
|
|
||||||
column_state = i2c_readNak();
|
|
||||||
|
|
||||||
out:
|
|
||||||
i2c_stop();
|
|
||||||
|
|
||||||
column_state = ~column_state;
|
column_state = ~column_state;
|
||||||
} else {
|
} else {
|
||||||
|
@ -476,11 +476,8 @@ static void select_col(uint8_t col)
|
||||||
} else {
|
} else {
|
||||||
// set active col low : 0
|
// set active col low : 0
|
||||||
// set other cols hi-Z : 1
|
// set other cols hi-Z : 1
|
||||||
expander_status = i2c_start(I2C_ADDR_WRITE); if (expander_status) goto out;
|
uint8_t port = 0xFF & ~(1<<col);
|
||||||
expander_status = i2c_write(EXPANDER_COL_REGISTER); if (expander_status) goto out;
|
expander_status = i2c_writeReg(I2C_ADDR, EXPANDER_COL_REGISTER, &port, 1, I2C_TIMEOUT);
|
||||||
expander_status = i2c_write(0xFF & ~(1<<col)); if (expander_status) goto out;
|
|
||||||
out:
|
|
||||||
i2c_stop();
|
|
||||||
}
|
}
|
||||||
} else {
|
} else {
|
||||||
// select on teensy
|
// select on teensy
|
||||||
|
|
|
@ -28,5 +28,5 @@ SLEEP_LED_ENABLE = no
|
||||||
RGBLIGHT_ENABLE = no
|
RGBLIGHT_ENABLE = no
|
||||||
|
|
||||||
# project specific files
|
# project specific files
|
||||||
SRC = twimaster.c \
|
QUANTUM_LIB_SRC += i2c_master.c
|
||||||
matrix.c
|
SRC += matrix.c
|
||||||
|
|
|
@ -1,207 +0,0 @@
|
||||||
/*************************************************************************
|
|
||||||
* Title: I2C master library using hardware TWI interface
|
|
||||||
* Author: Peter Fleury <pfleury@gmx.ch> http://jump.to/fleury
|
|
||||||
* File: $Id: twimaster.c,v 1.3 2005/07/02 11:14:21 Peter Exp $
|
|
||||||
* Software: AVR-GCC 3.4.3 / avr-libc 1.2.3
|
|
||||||
* Target: any AVR device with hardware TWI
|
|
||||||
* Usage: API compatible with I2C Software Library i2cmaster.h
|
|
||||||
**************************************************************************/
|
|
||||||
#include <inttypes.h>
|
|
||||||
#include <compat/twi.h>
|
|
||||||
|
|
||||||
#include "i2cmaster.h"
|
|
||||||
|
|
||||||
/* define CPU frequency in Hz here if not defined in Makefile */
|
|
||||||
#ifndef F_CPU
|
|
||||||
#define F_CPU 16000000UL
|
|
||||||
#endif
|
|
||||||
|
|
||||||
/* I2C clock in Hz */
|
|
||||||
#define SCL_CLOCK 400000L
|
|
||||||
|
|
||||||
|
|
||||||
/*************************************************************************
|
|
||||||
Initialization of the I2C bus interface. Need to be called only once
|
|
||||||
*************************************************************************/
|
|
||||||
void i2c_init(void)
|
|
||||||
{
|
|
||||||
/* initialize TWI clock
|
|
||||||
* minimal values in Bit Rate Register (TWBR) and minimal Prescaler
|
|
||||||
* bits in the TWI Status Register should give us maximal possible
|
|
||||||
* I2C bus speed - about 444 kHz
|
|
||||||
*
|
|
||||||
* for more details, see 20.5.2 in ATmega16/32 secification
|
|
||||||
*/
|
|
||||||
|
|
||||||
TWSR = 0; /* no prescaler */
|
|
||||||
TWBR = 10; /* 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 */
|
|
Loading…
Reference in a new issue