Initial structure for Ergodox as subprojects
Only the EZ default keymaps compiles at the moment though.
This commit is contained in:
Fred Sundvik
parent
30003d48f9
commit
9af995c59b
219 changed files with 58 additions and 23 deletions
|
|
@ -1,208 +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 Mhz 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…
Add table
Add a link
Reference in a new issue