Co-authored-by: Joel Challis <git@zvecr.com>pull/22021/head
@ -1,87 +0,0 @@ | |||
/* | |||
Copyright 2017 Balz Guenat | |||
based on work by Jun Wako <wakojun@gmail.com> | |||
This program is free software: you can redistribute it and/or modify | |||
it under the terms of the GNU General Public License as published by | |||
the Free Software Foundation, either version 2 of the License, or | |||
(at your option) any later version. | |||
This program is distributed in the hope that it will be useful, | |||
but WITHOUT ANY WARRANTY; without even the implied warranty of | |||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |||
GNU General Public License for more details. | |||
You should have received a copy of the GNU General Public License | |||
along with this program. If not, see <http://www.gnu.org/licenses/>. | |||
*/ | |||
#include "actuation_point.h" | |||
#include "i2c.h" | |||
/////////////////////////////////////////////////////////////////////////////// | |||
// | |||
// AD5258 I2C digital potentiometer | |||
// http://www.analog.com/media/en/technical-documentation/data-sheets/AD5258.pdf | |||
// | |||
#define AD5258_ADDR 0b0011000 | |||
#define AD5258_INST_RDAC 0x00 | |||
#define AD5258_INST_EEPROM 0x20 | |||
uint8_t read_rdac(void) { | |||
// read RDAC register | |||
i2c_start_write(AD5258_ADDR); | |||
i2c_master_write(AD5258_INST_RDAC); | |||
i2c_start_read(AD5258_ADDR); | |||
uint8_t ret = i2c_master_read(I2C_NACK); | |||
i2c_master_stop(); | |||
return ret; | |||
}; | |||
uint8_t read_eeprom(void) { | |||
i2c_start_write(AD5258_ADDR); | |||
i2c_master_write(AD5258_INST_EEPROM); | |||
i2c_start_read(AD5258_ADDR); | |||
uint8_t ret = i2c_master_read(I2C_NACK); | |||
i2c_master_stop(); | |||
return ret; | |||
}; | |||
void write_rdac(uint8_t rdac) { | |||
// write RDAC register: | |||
i2c_start_write(AD5258_ADDR); | |||
i2c_master_write(AD5258_INST_RDAC); | |||
i2c_master_write(rdac & 0x3F); | |||
i2c_master_stop(); | |||
}; | |||
void actuation_point_up(void) { | |||
// write RDAC register: lower value makes actuation point shallow | |||
uint8_t rdac = read_rdac(); | |||
if (rdac == 0) | |||
write_rdac(0); | |||
else | |||
write_rdac(rdac-1); | |||
}; | |||
void actuation_point_down(void) { | |||
// write RDAC register: higher value makes actuation point deep | |||
uint8_t rdac = read_rdac(); | |||
if (rdac == 63) | |||
write_rdac(63); | |||
else | |||
write_rdac(rdac+1); | |||
}; | |||
void adjust_actuation_point(int offset) { | |||
i2c_master_init(); | |||
uint8_t rdac = read_eeprom() + offset; | |||
if (rdac > 63) { // protects from under and overflows | |||
if (offset > 0) | |||
write_rdac(63); | |||
else | |||
write_rdac(0); | |||
} else { | |||
write_rdac(rdac); | |||
} | |||
} |
@ -0,0 +1,52 @@ | |||
/* | |||
Copyright 2017 Balz Guenat | |||
based on work by Jun Wako <wakojun@gmail.com> | |||
This program is free software: you can redistribute it and/or modify | |||
it under the terms of the GNU General Public License as published by | |||
the Free Software Foundation, either version 2 of the License, or | |||
(at your option) any later version. | |||
This program is distributed in the hope that it will be useful, | |||
but WITHOUT ANY WARRANTY; without even the implied warranty of | |||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |||
GNU General Public License for more details. | |||
You should have received a copy of the GNU General Public License | |||
along with this program. If not, see <http://www.gnu.org/licenses/>. | |||
*/ | |||
#include "ad5258.h" | |||
#include "i2c_master.h" | |||
/////////////////////////////////////////////////////////////////////////////// | |||
// | |||
// AD5258 I2C digital potentiometer | |||
// http://www.analog.com/media/en/technical-documentation/data-sheets/AD5258.pdf | |||
// | |||
#define AD5258_I2C_ADDRESS 0x18 | |||
#define AD5258_INST_RDAC 0x00 | |||
#define AD5258_INST_EEPROM 0x20 | |||
void ad5258_init(void) { | |||
i2c_init(); | |||
} | |||
uint8_t ad5258_read_rdac(void) { | |||
// read RDAC register | |||
uint8_t ret = 0; | |||
i2c_readReg(AD5258_I2C_ADDRESS, AD5258_INST_RDAC, &ret, 1, 100); | |||
return ret; | |||
} | |||
uint8_t ad5258_read_eeprom(void) { | |||
uint8_t ret = 0; | |||
i2c_readReg(AD5258_I2C_ADDRESS, AD5258_INST_EEPROM, &ret, 1, 100); | |||
return ret; | |||
} | |||
void ad5258_write_rdac(uint8_t rdac) { | |||
// write RDAC register: | |||
uint8_t data = rdac & 0x3F; | |||
i2c_writeReg(AD5258_I2C_ADDRESS, AD5258_INST_RDAC, &data, 1, 100); | |||
} |
@ -0,0 +1,28 @@ | |||
/* | |||
Copyright 2017 Balz Guenat | |||
This program is free software: you can redistribute it and/or modify | |||
it under the terms of the GNU General Public License as published by | |||
the Free Software Foundation, either version 2 of the License, or | |||
(at your option) any later version. | |||
This program is distributed in the hope that it will be useful, | |||
but WITHOUT ANY WARRANTY; without even the implied warranty of | |||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |||
GNU General Public License for more details. | |||
You should have received a copy of the GNU General Public License | |||
along with this program. If not, see <http://www.gnu.org/licenses/>. | |||
*/ | |||
#pragma once | |||
#include <stdint.h> | |||
void ad5258_init(void); | |||
uint8_t ad5258_read_rdac(void); | |||
uint8_t ad5258_read_eeprom(void); | |||
void ad5258_write_rdac(uint8_t rdac); |
@ -1,162 +0,0 @@ | |||
#include <util/twi.h> | |||
#include <avr/io.h> | |||
#include <stdlib.h> | |||
#include <avr/interrupt.h> | |||
#include <util/twi.h> | |||
#include <stdbool.h> | |||
#include "i2c.h" | |||
#ifdef USE_I2C | |||
// Limits the amount of we wait for any one i2c transaction. | |||
// Since were running SCL line 100kHz (=> 10μs/bit), and each transactions is | |||
// 9 bits, a single transaction will take around 90μs to complete. | |||
// | |||
// (F_CPU/SCL_CLOCK) => # of μC cycles to transfer a bit | |||
// poll loop takes at least 8 clock cycles to execute | |||
#define I2C_LOOP_TIMEOUT (9+1)*(F_CPU/SCL_CLOCK)/8 | |||
#define BUFFER_POS_INC() (slave_buffer_pos = (slave_buffer_pos+1)%SLAVE_BUFFER_SIZE) | |||
volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE]; | |||
static volatile uint8_t slave_buffer_pos; | |||
static volatile bool slave_has_register_set = false; | |||
// Wait for an i2c operation to finish | |||
inline static | |||
void i2c_delay(void) { | |||
uint16_t lim = 0; | |||
while(!(TWCR & (1<<TWINT)) && lim < I2C_LOOP_TIMEOUT) | |||
lim++; | |||
// easier way, but will wait slightly longer | |||
// _delay_us(100); | |||
} | |||
// Setup twi to run at 100kHz | |||
void i2c_master_init(void) { | |||
// no prescaler | |||
TWSR = 0; | |||
// Set TWI clock frequency to SCL_CLOCK. Need TWBR>10. | |||
// Check datasheets for more info. | |||
TWBR = ((F_CPU/SCL_CLOCK)-16)/2; | |||
} | |||
// Start a transaction with the given i2c slave address. The direction of the | |||
// transfer is set with I2C_READ and I2C_WRITE. | |||
// returns: 0 => success | |||
// 1 => error | |||
uint8_t i2c_master_start(uint8_t address) { | |||
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTA); | |||
i2c_delay(); | |||
// check that we started successfully | |||
if ( (TW_STATUS != TW_START) && (TW_STATUS != TW_REP_START)) | |||
return 1; | |||
TWDR = address; | |||
TWCR = (1<<TWINT) | (1<<TWEN); | |||
i2c_delay(); | |||
if ( (TW_STATUS != TW_MT_SLA_ACK) && (TW_STATUS != TW_MR_SLA_ACK) ) | |||
return 1; // slave did not acknowledge | |||
else | |||
return 0; // success | |||
} | |||
// Finish the i2c transaction. | |||
void i2c_master_stop(void) { | |||
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO); | |||
uint16_t lim = 0; | |||
while(!(TWCR & (1<<TWSTO)) && lim < I2C_LOOP_TIMEOUT) | |||
lim++; | |||
} | |||
// Write one byte to the i2c slave. | |||
// returns 0 => slave ACK | |||
// 1 => slave NACK | |||
uint8_t i2c_master_write(uint8_t data) { | |||
TWDR = data; | |||
TWCR = (1<<TWINT) | (1<<TWEN); | |||
i2c_delay(); | |||
// check if the slave acknowledged us | |||
return (TW_STATUS == TW_MT_DATA_ACK) ? 0 : 1; | |||
} | |||
// Read one byte from the i2c slave. If ack=1 the slave is acknowledged, | |||
// if ack=0 the acknowledge bit is not set. | |||
// returns: byte read from i2c device | |||
uint8_t i2c_master_read(int ack) { | |||
TWCR = (1<<TWINT) | (1<<TWEN) | (ack<<TWEA); | |||
i2c_delay(); | |||
return TWDR; | |||
} | |||
void i2c_reset_state(void) { | |||
TWCR = 0; | |||
} | |||
void i2c_slave_init(uint8_t address) { | |||
TWAR = address << 0; // slave i2c address | |||
// TWEN - twi enable | |||
// TWEA - enable address acknowledgement | |||
// TWINT - twi interrupt flag | |||
// TWIE - enable the twi interrupt | |||
TWCR = (1<<TWIE) | (1<<TWEA) | (1<<TWINT) | (1<<TWEN); | |||
} | |||
ISR(TWI_vect); | |||
ISR(TWI_vect) { | |||
uint8_t ack = 1; | |||
switch(TW_STATUS) { | |||
case TW_SR_SLA_ACK: | |||
// this device has been addressed as a slave receiver | |||
slave_has_register_set = false; | |||
break; | |||
case TW_SR_DATA_ACK: | |||
// this device has received data as a slave receiver | |||
// The first byte that we receive in this transaction sets the location | |||
// of the read/write location of the slaves memory that it exposes over | |||
// i2c. After that, bytes will be written at slave_buffer_pos, incrementing | |||
// slave_buffer_pos after each write. | |||
if(!slave_has_register_set) { | |||
slave_buffer_pos = TWDR; | |||
// don't acknowledge the master if this memory loctaion is out of bounds | |||
if ( slave_buffer_pos >= SLAVE_BUFFER_SIZE ) { | |||
ack = 0; | |||
slave_buffer_pos = 0; | |||
} | |||
slave_has_register_set = true; | |||
} else { | |||
i2c_slave_buffer[slave_buffer_pos] = TWDR; | |||
BUFFER_POS_INC(); | |||
} | |||
break; | |||
case TW_ST_SLA_ACK: | |||
case TW_ST_DATA_ACK: | |||
// master has addressed this device as a slave transmitter and is | |||
// requesting data. | |||
TWDR = i2c_slave_buffer[slave_buffer_pos]; | |||
BUFFER_POS_INC(); | |||
break; | |||
case TW_BUS_ERROR: // something went wrong, reset twi state | |||
TWCR = 0; | |||
default: | |||
break; | |||
} | |||
// Reset everything, so we are ready for the next TWI interrupt | |||
TWCR |= (1<<TWIE) | (1<<TWINT) | (ack<<TWEA) | (1<<TWEN); | |||
} | |||
#endif |
@ -1,46 +0,0 @@ | |||
#pragma once | |||
#include <stdint.h> | |||
#ifndef F_CPU | |||
#define F_CPU 16000000UL | |||
#endif | |||
#define I2C_READ 1 | |||
#define I2C_WRITE 0 | |||
#define I2C_ACK 1 | |||
#define I2C_NACK 0 | |||
#define SLAVE_BUFFER_SIZE 0x10 | |||
// i2c SCL clock frequency | |||
#define SCL_CLOCK 400000L | |||
extern volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE]; | |||
void i2c_master_init(void); | |||
uint8_t i2c_master_start(uint8_t address); | |||
void i2c_master_stop(void); | |||
uint8_t i2c_master_write(uint8_t data); | |||
uint8_t i2c_master_read(int); | |||
void i2c_reset_state(void); | |||
void i2c_slave_init(uint8_t address); | |||
static inline unsigned char i2c_start_read(unsigned char addr) { | |||
return i2c_master_start((addr << 1) | I2C_READ); | |||
} | |||
static inline unsigned char i2c_start_write(unsigned char addr) { | |||
return i2c_master_start((addr << 1) | I2C_WRITE); | |||
} | |||
// from SSD1306 scrips | |||
extern unsigned char i2c_rep_start(unsigned char addr); | |||
extern void i2c_start_wait(unsigned char addr); | |||
extern unsigned char i2c_readAck(void); | |||
extern unsigned char i2c_readNak(void); | |||
extern unsigned char i2c_read(unsigned char ack); | |||
#define i2c_read(ack) (ack) ? i2c_readAck() : i2c_readNak(); |
@ -1,87 +0,0 @@ | |||
/* | |||
Copyright 2017 Balz Guenat | |||
based on work by Jun Wako <wakojun@gmail.com> | |||
This program is free software: you can redistribute it and/or modify | |||
it under the terms of the GNU General Public License as published by | |||
the Free Software Foundation, either version 2 of the License, or | |||
(at your option) any later version. | |||
This program is distributed in the hope that it will be useful, | |||
but WITHOUT ANY WARRANTY; without even the implied warranty of | |||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |||
GNU General Public License for more details. | |||
You should have received a copy of the GNU General Public License | |||
along with this program. If not, see <http://www.gnu.org/licenses/>. | |||
*/ | |||
#include "actuation_point.h" | |||
#include "i2c.h" | |||
/////////////////////////////////////////////////////////////////////////////// | |||
// | |||
// AD5258 I2C digital potentiometer | |||
// http://www.analog.com/media/en/technical-documentation/data-sheets/AD5258.pdf | |||
// | |||
#define AD5258_ADDR 0b0011000 | |||
#define AD5258_INST_RDAC 0x00 | |||
#define AD5258_INST_EEPROM 0x20 | |||
uint8_t read_rdac(void) { | |||
// read RDAC register | |||
i2c_start_write(AD5258_ADDR); | |||
i2c_master_write(AD5258_INST_RDAC); | |||
i2c_start_read(AD5258_ADDR); | |||
uint8_t ret = i2c_master_read(I2C_NACK); | |||
i2c_master_stop(); | |||
return ret; | |||
}; | |||
uint8_t read_eeprom(void) { | |||
i2c_start_write(AD5258_ADDR); | |||
i2c_master_write(AD5258_INST_EEPROM); | |||
i2c_start_read(AD5258_ADDR); | |||
uint8_t ret = i2c_master_read(I2C_NACK); | |||
i2c_master_stop(); | |||
return ret; | |||
}; | |||
void write_rdac(uint8_t rdac) { | |||
// write RDAC register: | |||
i2c_start_write(AD5258_ADDR); | |||
i2c_master_write(AD5258_INST_RDAC); | |||
i2c_master_write(rdac & 0x3F); | |||
i2c_master_stop(); | |||
}; | |||
void actuation_point_up(void) { | |||
// write RDAC register: lower value makes actuation point shallow | |||
uint8_t rdac = read_rdac(); | |||
if (rdac == 0) | |||
write_rdac(0); | |||
else | |||
write_rdac(rdac-1); | |||
}; | |||
void actuation_point_down(void) { | |||
// write RDAC register: higher value makes actuation point deep | |||
uint8_t rdac = read_rdac(); | |||
if (rdac == 63) | |||
write_rdac(63); | |||
else | |||
write_rdac(rdac+1); | |||
}; | |||
void adjust_actuation_point(int offset) { | |||
i2c_master_init(); | |||
uint8_t rdac = read_eeprom() + offset; | |||
if (rdac > 63) { // protects from under and overflows | |||
if (offset > 0) | |||
write_rdac(63); | |||
else | |||
write_rdac(0); | |||
} else { | |||
write_rdac(rdac); | |||
} | |||
} |
@ -0,0 +1,52 @@ | |||
/* | |||
Copyright 2017 Balz Guenat | |||
based on work by Jun Wako <wakojun@gmail.com> | |||
This program is free software: you can redistribute it and/or modify | |||
it under the terms of the GNU General Public License as published by | |||
the Free Software Foundation, either version 2 of the License, or | |||
(at your option) any later version. | |||
This program is distributed in the hope that it will be useful, | |||
but WITHOUT ANY WARRANTY; without even the implied warranty of | |||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |||
GNU General Public License for more details. | |||
You should have received a copy of the GNU General Public License | |||
along with this program. If not, see <http://www.gnu.org/licenses/>. | |||
*/ | |||
#include "ad5258.h" | |||
#include "i2c_master.h" | |||
/////////////////////////////////////////////////////////////////////////////// | |||
// | |||
// AD5258 I2C digital potentiometer | |||
// http://www.analog.com/media/en/technical-documentation/data-sheets/AD5258.pdf | |||
// | |||
#define AD5258_I2C_ADDRESS 0x18 | |||
#define AD5258_INST_RDAC 0x00 | |||
#define AD5258_INST_EEPROM 0x20 | |||
void ad5258_init(void) { | |||
i2c_init(); | |||
} | |||
uint8_t ad5258_read_rdac(void) { | |||
// read RDAC register | |||
uint8_t ret = 0; | |||
i2c_readReg(AD5258_I2C_ADDRESS, AD5258_INST_RDAC, &ret, 1, 100); | |||
return ret; | |||
} | |||
uint8_t ad5258_read_eeprom(void) { | |||
uint8_t ret = 0; | |||
i2c_readReg(AD5258_I2C_ADDRESS, AD5258_INST_EEPROM, &ret, 1, 100); | |||
return ret; | |||
} | |||
void ad5258_write_rdac(uint8_t rdac) { | |||
// write RDAC register: | |||
uint8_t data = rdac & 0x3F; | |||
i2c_writeReg(AD5258_I2C_ADDRESS, AD5258_INST_RDAC, &data, 1, 100); | |||
} |
@ -0,0 +1,28 @@ | |||
/* | |||
Copyright 2017 Balz Guenat | |||
This program is free software: you can redistribute it and/or modify | |||
it under the terms of the GNU General Public License as published by | |||
the Free Software Foundation, either version 2 of the License, or | |||
(at your option) any later version. | |||
This program is distributed in the hope that it will be useful, | |||
but WITHOUT ANY WARRANTY; without even the implied warranty of | |||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |||
GNU General Public License for more details. | |||
You should have received a copy of the GNU General Public License | |||
along with this program. If not, see <http://www.gnu.org/licenses/>. | |||
*/ | |||
#pragma once | |||
#include <stdint.h> | |||
void ad5258_init(void); | |||
uint8_t ad5258_read_rdac(void); | |||
uint8_t ad5258_read_eeprom(void); | |||
void ad5258_write_rdac(uint8_t rdac); |
@ -1,162 +0,0 @@ | |||
#include <util/twi.h> | |||
#include <avr/io.h> | |||
#include <stdlib.h> | |||
#include <avr/interrupt.h> | |||
#include <util/twi.h> | |||
#include <stdbool.h> | |||
#include "i2c.h" | |||
#ifdef USE_I2C | |||
// Limits the amount of we wait for any one i2c transaction. | |||
// Since were running SCL line 100kHz (=> 10μs/bit), and each transactions is | |||
// 9 bits, a single transaction will take around 90μs to complete. | |||
// | |||
// (F_CPU/SCL_CLOCK) => # of μC cycles to transfer a bit | |||
// poll loop takes at least 8 clock cycles to execute | |||
#define I2C_LOOP_TIMEOUT (9+1)*(F_CPU/SCL_CLOCK)/8 | |||
#define BUFFER_POS_INC() (slave_buffer_pos = (slave_buffer_pos+1)%SLAVE_BUFFER_SIZE) | |||
volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE]; | |||
static volatile uint8_t slave_buffer_pos; | |||
static volatile bool slave_has_register_set = false; | |||
// Wait for an i2c operation to finish | |||
inline static | |||
void i2c_delay(void) { | |||
uint16_t lim = 0; | |||
while(!(TWCR & (1<<TWINT)) && lim < I2C_LOOP_TIMEOUT) | |||
lim++; | |||
// easier way, but will wait slightly longer | |||
// _delay_us(100); | |||
} | |||
// Setup twi to run at 100kHz | |||
void i2c_master_init(void) { | |||
// no prescaler | |||
TWSR = 0; | |||
// Set TWI clock frequency to SCL_CLOCK. Need TWBR>10. | |||
// Check datasheets for more info. | |||
TWBR = ((F_CPU/SCL_CLOCK)-16)/2; | |||
} | |||
// Start a transaction with the given i2c slave address. The direction of the | |||
// transfer is set with I2C_READ and I2C_WRITE. | |||
// returns: 0 => success | |||
// 1 => error | |||
uint8_t i2c_master_start(uint8_t address) { | |||
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTA); | |||
i2c_delay(); | |||
// check that we started successfully | |||
if ( (TW_STATUS != TW_START) && (TW_STATUS != TW_REP_START)) | |||
return 1; | |||
TWDR = address; | |||
TWCR = (1<<TWINT) | (1<<TWEN); | |||
i2c_delay(); | |||
if ( (TW_STATUS != TW_MT_SLA_ACK) && (TW_STATUS != TW_MR_SLA_ACK) ) | |||
return 1; // slave did not acknowledge | |||
else | |||
return 0; // success | |||
} | |||
// Finish the i2c transaction. | |||
void i2c_master_stop(void) { | |||
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO); | |||
uint16_t lim = 0; | |||
while(!(TWCR & (1<<TWSTO)) && lim < I2C_LOOP_TIMEOUT) | |||
lim++; | |||
} | |||
// Write one byte to the i2c slave. | |||
// returns 0 => slave ACK | |||
// 1 => slave NACK | |||
uint8_t i2c_master_write(uint8_t data) { | |||
TWDR = data; | |||
TWCR = (1<<TWINT) | (1<<TWEN); | |||
i2c_delay(); | |||
// check if the slave acknowledged us | |||
return (TW_STATUS == TW_MT_DATA_ACK) ? 0 : 1; | |||
} | |||
// Read one byte from the i2c slave. If ack=1 the slave is acknowledged, | |||
// if ack=0 the acknowledge bit is not set. | |||
// returns: byte read from i2c device | |||
uint8_t i2c_master_read(int ack) { | |||
TWCR = (1<<TWINT) | (1<<TWEN) | (ack<<TWEA); | |||
i2c_delay(); | |||
return TWDR; | |||
} | |||
void i2c_reset_state(void) { | |||
TWCR = 0; | |||
} | |||
void i2c_slave_init(uint8_t address) { | |||
TWAR = address << 0; // slave i2c address | |||
// TWEN - twi enable | |||
// TWEA - enable address acknowledgement | |||
// TWINT - twi interrupt flag | |||
// TWIE - enable the twi interrupt | |||
TWCR = (1<<TWIE) | (1<<TWEA) | (1<<TWINT) | (1<<TWEN); | |||
} | |||
ISR(TWI_vect); | |||
ISR(TWI_vect) { | |||
uint8_t ack = 1; | |||
switch(TW_STATUS) { | |||
case TW_SR_SLA_ACK: | |||
// this device has been addressed as a slave receiver | |||
slave_has_register_set = false; | |||
break; | |||
case TW_SR_DATA_ACK: | |||
// this device has received data as a slave receiver | |||
// The first byte that we receive in this transaction sets the location | |||
// of the read/write location of the slaves memory that it exposes over | |||
// i2c. After that, bytes will be written at slave_buffer_pos, incrementing | |||
// slave_buffer_pos after each write. | |||
if(!slave_has_register_set) { | |||
slave_buffer_pos = TWDR; | |||
// don't acknowledge the master if this memory loctaion is out of bounds | |||
if ( slave_buffer_pos >= SLAVE_BUFFER_SIZE ) { | |||
ack = 0; | |||
slave_buffer_pos = 0; | |||
} | |||
slave_has_register_set = true; | |||
} else { | |||
i2c_slave_buffer[slave_buffer_pos] = TWDR; | |||
BUFFER_POS_INC(); | |||
} | |||
break; | |||
case TW_ST_SLA_ACK: | |||
case TW_ST_DATA_ACK: | |||
// master has addressed this device as a slave transmitter and is | |||
// requesting data. | |||
TWDR = i2c_slave_buffer[slave_buffer_pos]; | |||
BUFFER_POS_INC(); | |||
break; | |||
case TW_BUS_ERROR: // something went wrong, reset twi state | |||
TWCR = 0; | |||
default: | |||
break; | |||
} | |||
// Reset everything, so we are ready for the next TWI interrupt | |||
TWCR |= (1<<TWIE) | (1<<TWINT) | (ack<<TWEA) | (1<<TWEN); | |||
} | |||
#endif |
@ -1,46 +0,0 @@ | |||
#pragma once | |||
#include <stdint.h> | |||
#ifndef F_CPU | |||
#define F_CPU 16000000UL | |||
#endif | |||
#define I2C_READ 1 | |||
#define I2C_WRITE 0 | |||
#define I2C_ACK 1 | |||
#define I2C_NACK 0 | |||
#define SLAVE_BUFFER_SIZE 0x10 | |||
// i2c SCL clock frequency | |||
#define SCL_CLOCK 400000L | |||
extern volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE]; | |||
void i2c_master_init(void); | |||
uint8_t i2c_master_start(uint8_t address); | |||
void i2c_master_stop(void); | |||
uint8_t i2c_master_write(uint8_t data); | |||
uint8_t i2c_master_read(int); | |||
void i2c_reset_state(void); | |||
void i2c_slave_init(uint8_t address); | |||
static inline unsigned char i2c_start_read(unsigned char addr) { | |||
return i2c_master_start((addr << 1) | I2C_READ); | |||
} | |||
static inline unsigned char i2c_start_write(unsigned char addr) { | |||
return i2c_master_start((addr << 1) | I2C_WRITE); | |||
} | |||
// from SSD1306 scrips | |||
extern unsigned char i2c_rep_start(unsigned char addr); | |||
extern void i2c_start_wait(unsigned char addr); | |||
extern unsigned char i2c_readAck(void); | |||
extern unsigned char i2c_readNak(void); | |||
extern unsigned char i2c_read(unsigned char ack); | |||
#define i2c_read(ack) (ack) ? i2c_readAck() : i2c_readNak(); |