Failure with a clock on ATMega48
The most excellent clock on the stalled LCD display and ATMega48 supermicrochip. But failed.
UPD : Krona died, cut off two wires, applied sleep, 0.3-1.6mA
That is, the clock, of course, works, but, alas, they will not work for long.
A long time ago in a box in the far bedside I had a pair of seven-segment LCD indicators. And just as long ago I wanted to take them into circulation and build on the basis of one of them a watch. Once upon a time: this is, literally, seven years. It was then, in 2011, I became interested in electronics. Without thinking for a long time, I ordered all sorts of things in one good online store (no, not on Ali; I'm not sure that he was already then). But somehow I did not work out to create the eternal. After several etched cards, I abandoned this entertainment and forgot.
And now, when Ali came with a package that contained mockups, a bag of 595s in dip packages, Tiny RTC on ds1307 , and, most importantly, USBasp , it was time to return to the old idea. From the old stash I had an ATMega48 , one that is about 28 feet, lm7805 , every small things in the form of resistors / capacitors / buttons, and, in fact, an indicator on 40 legs.
Generally speaking, it was originally planned to use AtTiny13, which I also have lying around, but having figured it out, I didn’t figure out how to use it with 5 legs to display the indicator, read two buttons, and communicate with the clock on i2c. With 28 legs of mega, it’s no longer necessary to save and pervert with the union of legs. Although, of course, even in this case you cannot do without the 595s. But if with the tini I planned to display all 32 bits of data for the indicator sequentially, then with mega, you can display a picture of all four chips at once in parallel.
All 595s are hidden under the indicator. The photo shows the findings of the chip housing.
595 was used exactly four pieces, because the indicator, although it has 40 legs, only 32 are displayed on the segments. Alas, this is only a 3.5 indicator, that is, it has 3 full digits, plus one. There is a symbol of seconds, but no indication for AM / PM. But what to eat. I would not like to order a more advanced indicator, having never collected anything on my LCD indicators.
Working documentation on the indicator. The tester had to find out which leg corresponds to which segment.
Well, then the matter of technology. There has never been a scheme, but everything is obvious there. It was necessary only to allocate four legs to the input of buffers, a common foot for the indicator, a foot for SCLK / RCLK, a foot for OE, two legs for i2c, two legs for buttons. All this was, of course, wrong. Why I decided that OE should be brought to the controller, and SCLK can be combined with RCLK - I don’t remember myself. It was necessary to do just the opposite. And the common indicator wire on the controller is not needed at all, it was possible to get along with one of the conclusions of the first 595th (which I also, as a result, did).
Wires. A lot of them. Inside view.
View from the outside.
The most interesting thing about this whole project: the output code on the indicator. The subtlety is that the LCD indicator cannot just be energized and forgotten. It is necessary about a hundred times per second to change the polarity between the segments and the general contact, so that everything would be nice and pleasant to the eye. As a development environment, without further ado, I used the Arduino IDE, having only suffered a little in a couple of moments. First, I had to use the MiniCore package ( https://github.com/MCUdude/MiniCore ), because I had to write not for the big ready-made arduine, but for the weak and bare ATMega48. Secondly, a direct attempt to use the built-in library for i2c did not lead to anything. For some not entirely understandable reason, it did not want to work, had to find another library, and then cut it to meet its needs.
As it turned out, 4 kilobytes is very little. Especially if you write in C. It is possible, if I decided to switch to assembler, this restriction would not press so seriously, but remembering my past execsises in writing in an assembler for AVR, I didn’t have such a desire. And to write in C - a lot of space is necessary. Slightly put a bracket on by accident - a hundred bytes into the pipe.
Actually, the commented code
#include <avr/io.h>
#include <util/delay.h>
#include <avr/power.h>
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
// ds1307,
#define DS3231_I2C_ADDRESS 0x68
#define LCD_PORT PORTD
#define LCD_DDR DDRD
#define LCD_DATA1 PD0
#define LCD_DATA2 PD1
#define LCD_DATA3 PD2
#define LCD_DATA4 PD3
#define LCD_SCLK PD4
#define LCD_OE PD5
#define LCD_COM PD6
#define KEY1_PORT PORTB
#define KEY1_DDR DDRB
#define KEY1_PIN PINB
#define KEY1 PB0
#define KEY2_PORT PORTD
#define KEY2_DDR DDRD
#define KEY2_PIN PIND
#define KEY2 PD7
#define DS1307SQ PB1
#define DS1307SQ_INT PCIE0
#define DS1307SQ_PORT PORTB
#define DS1307SQ_DDR DDRB
#define DS1307SQ_PIN PINB
#define DS1307SQ_VEC PCINT0_vect
#define DS1307SQ_MSK PCMSK0
// . , -, , -
#define LM335_PORT PORTC
#define LM335_DDR DDRC
#define LM335 PC3
//
unsigned char lcd_buf[4];
#define MODE_MAIN 0
#define MODE_CALENDAR 1
#define MODE_YEAR 2
#define MODE_TERMOMETER 3 //
#define MODE_VOLTMETER 4 //
#define MODE_SET_MINUTE 5
#define MODE_SET_HOUR 6
#define MODE_SET_DAY 7
#define MODE_SET_MONTH 8
#define MODE_SET_YEAR 9
#define MODE_SECOND 10
#define MODE_DEBUG 11 //
// 10ms ()
#define MODE_TIMEOUT 20 // 2
#define MODE_TIMEOUT_SET 100 // 10
#define KEY_TIMEOUT 10 // 1
byte mode = MODE_MAIN;
byte mode_timeout = 0;
byte key1_press = 0;
byte key1_time = 0;
byte key2_press = 0;
byte key2_time = 0;
byte cycle_count_10 = 0; //
byte even_10 = 0; // 1/10
// ds1307
byte second;
byte minute;
byte hour;
byte dayOfWeek;
byte dayOfMonth;
byte month;
byte year;
volatile byte need_render_int = 1;
uint8_t porthistory = 0xFF;
volatile uint8_t debug_value = 0;
byte twi_problems = 0;
// ds1307 SQ
// ,
ISR(DS1307SQ_VEC) {
uint8_t changedbits = DS1307SQ_PIN ^ porthistory;
porthistory = DS1307SQ_PIN;
if (changedbits & _BV(DS1307SQ) && porthistory & _BV(DS1307SQ)) {
need_render_int = 1;
}
}
//
void lcd_num(char pos, char num) {
unsigned char buf = 0b01110110;
if (pos < 1 || pos > 3) {
return;
}
switch (num) {
case 0:
// 3- , ?
// , ,
// :-(
if (pos == 3) {
buf = 0b11101110;
} else {
buf = 0b11100111;
}
break;
case 1:
if (pos == 3) {
buf = 0b10001000;
} else {
buf = 0b10000001;
}
break;
case 2:
buf = 0b11010110;
break;
case 3:
if (pos == 3) {
buf = 0b11011100;
} else {
buf = 0b11010011;
}
break;
case 4:
if (pos == 3) {
buf = 0b10111000;
} else {
buf = 0b10110001;
}
break;
case 5:
if (pos == 3) {
buf = 0b01111100;
} else {
buf = 0b01110011;
}
break;
case 6:
if (pos == 3) {
buf = 0b01111110;
} else {
buf = 0b01110111;
}
break;
case 7:
if (pos == 3) {
buf = 0b11001000;
} else {
buf = 0b11000001;
}
break;
case 8:
if (pos == 3) {
buf = 0b11111110;
} else {
buf = 0b11110111;
}
break;
case 9:
if (pos == 3) {
buf = 0b11111100;
} else {
buf = 0b11110011;
}
break;
}
lcd_buf[pos] = buf;
}
//
void lcd_one(bool e) {
if (e) {
lcd_buf[0] |= (1 << 0);
} else {
lcd_buf[0] &= ~(1 << 0);
}
}
void lcd_sec(bool e) {
if (e) {
lcd_buf[0] |= (1 << 7);
} else {
lcd_buf[0] &= ~(1 << 7);
}
}
void lcd_minus(bool e) {
if (e) {
lcd_buf[0] |= (1 << 1);
} else {
lcd_buf[0] &= ~(1 << 1);
}
}
void lcd_plus(bool e) {
if (e) {
lcd_buf[0] |= (1 << 6);
} else {
lcd_buf[0] &= ~(1 << 6);
}
}
void lcd_lo(bool e) {
if (e) {
lcd_buf[0] |= (1 << 5);
} else {
lcd_buf[0] &= ~(1 << 5);
}
}
void lcd_over(bool e) {
if (e) {
lcd_buf[0] |= (1 << 4);
} else {
lcd_buf[0] &= ~(1 << 4);
}
}
void lcd_dot(int pos, bool e) {
int pos_buf;
if (pos == 1) {
pos_buf = 3;
} else if (pos == 2) {
pos_buf = 2;
} else if (pos == 3) {
pos_buf = 1;
} else {
return;
}
if (pos_buf == 3) {
if (e) {
lcd_buf[pos_buf] |= (1 << 0);
} else {
lcd_buf[pos_buf] &= ~(1 << 0);
}
} else {
if (e) {
lcd_buf[pos_buf] |= (1 << 3);
} else {
lcd_buf[pos_buf] &= ~(1 << 3);
}
}
}
// 100
// 595-,
void lcd_refresh() {
unsigned char data1 = lcd_buf[0];
unsigned char data2 = lcd_buf[1];
unsigned char data3 = lcd_buf[2];
unsigned char data4 = lcd_buf[3];
byte reverse = data1 & (1 << 3); //
if (reverse) { // ,
data1 = ~data1;
data2 = ~data2;
data3 = ~data3;
data4 = ~data4;
}
for (int i = 0; i < 8; i++) {
//
if (data1 & (1 << i)) {
LCD_PORT |= _BV(LCD_DATA1);
} else {
LCD_PORT &= ~_BV(LCD_DATA1);
}
if (data2 & (1 << i)) {
LCD_PORT |= _BV(LCD_DATA2);
} else {
LCD_PORT &= ~_BV(LCD_DATA2);
}
if (data3 & (1 << i)) {
LCD_PORT |= _BV(LCD_DATA3);
} else {
LCD_PORT &= ~_BV(LCD_DATA3);
}
if (data4 & (1 << i)) {
LCD_PORT |= _BV(LCD_DATA4);
} else {
LCD_PORT &= ~_BV(LCD_DATA4);
}
// SCLK 595-
sbi(LCD_PORT, LCD_SCLK);
// SCLK 595-
cbi(LCD_PORT, LCD_SCLK);
}
// SCLK
// SCLK RCLK ,
// .
// , -, .
// SCLK RCLK, OE (. 74HC595)
// .
sbi(LCD_PORT, LCD_SCLK);
cbi(LCD_PORT, LCD_SCLK);
// -
// - - , 1 40
// (- ; )
// 4 595-,
// ,
if (reverse) {
sbi(LCD_PORT, LCD_COM);
} else {
cbi(LCD_PORT, LCD_COM);
}
//
lcd_buf[0] ^= (1 << 3);
}
// ,
void do_render() {
lcd_buf[0] = 0;
lcd_buf[1] = 0;
lcd_buf[2] = 0;
lcd_buf[3] = 0;
if (twi_problems) {
lcd_lo(1);
}
if (mode == MODE_MAIN) {
lcd_num(3, minute % 10);
lcd_num(2, minute / 10);
byte hour1 = (hour <= 12) ? hour : (hour % 12);
lcd_num(1, hour1 % 10);
if (hour1 >= 10) {
lcd_one(1);
}
// , . .
// SQ ,
// ,
//
if (second % 2) {
lcd_sec(1);
}
} else if (mode == MODE_CALENDAR) {
lcd_num(3, dayOfMonth % 10);
lcd_num(2, dayOfMonth / 10);
lcd_num(1, month % 10);
if (month >= 10) {
lcd_one(1);
} else {
lcd_one(0);
}
lcd_dot(2, 1);
} else if (mode == MODE_YEAR) {
lcd_num(3, year % 10);
lcd_num(2, year / 10);
lcd_buf[1] = 0b10110011; // y.
} else if (mode == MODE_TERMOMETER) {
} else if (mode == MODE_VOLTMETER) {
} else if (mode == MODE_SET_MINUTE) {
if (even_10) {
lcd_num(3, minute % 10);
lcd_num(2, minute / 10);
}
byte hour1 = (hour <= 12) ? hour : (hour % 12);
lcd_num(1, hour1 % 10);
if (hour1 >= 10) {
lcd_one(1);
} else {
lcd_one(0);
}
lcd_sec(1);
} else if (mode == MODE_SET_HOUR) {
lcd_num(3, minute % 10);
lcd_num(2, minute / 10);
if (even_10) {
byte hour1 = (hour <= 12) ? hour : (hour % 12);
lcd_num(1, hour1 % 10);
if (hour1 >= 10) {
lcd_one(1);
} else {
lcd_one(0);
}
if (hour > 12) {
lcd_over(1);
} else {
lcd_over(0);
}
}
lcd_sec(1);
} else if (mode == MODE_SET_DAY) {
if (even_10) {
lcd_num(3, dayOfMonth % 10);
lcd_num(2, dayOfMonth / 10);
}
lcd_num(1, month % 10);
if (month >= 10) {
lcd_one(1);
} else {
lcd_one(0);
}
lcd_dot(2, 1);
} else if (mode == MODE_SET_MONTH) {
lcd_num(3, dayOfMonth % 10);
lcd_num(2, dayOfMonth / 10);
if (even_10) {
lcd_num(1, month % 10);
if (month >= 10) {
lcd_one(1);
} else {
lcd_one(0);
}
}
lcd_dot(2, 1);
} else if (mode == MODE_SET_YEAR) {
if (even_10) {
lcd_num(3, year % 10);
lcd_num(2, year / 10);
}
lcd_buf[1] = 0b10110011;
} else if (mode == MODE_SECOND) {
lcd_sec(1);
lcd_num(3, second % 10);
lcd_num(2, second / 10);
} else if (mode == MODE_DEBUG) {
byte d = debug_value;
lcd_num(3, d % 10);
d /= 10;
lcd_num(2, d % 10);
lcd_num(2, d / 10);
}
}
int main(void)
{
// - .
// , , .
// ACSR = (1<<ACD);
ADCSRA = (0<<ADEN);
PRR = (1<<PRTIM0) | (1<<PRTIM1) | (1<<PRTIM2) | (1<<PRSPI) | (1<<PRADC) | (1<<PRUSART0);
//
DDRB = 0x00;
PORTB = 0xff;
DDRC = 0x00;
PORTC = 0xff;
DDRD = 0x00;
PORTD = 0xff;
lcd_buf[0] = 0x0;
lcd_buf[1] = 0x0;
lcd_buf[2] = 0x0;
lcd_buf[3] = 0x0;
twi_begin();
// . usbasp,
// , ,
// DDRB |= _BV(PB7);
// PORTB |= _BV(PB7); // off
// -
LCD_DDR |= (_BV(LCD_DATA1) | _BV(LCD_DATA2) | _BV(LCD_DATA3) | _BV(LCD_DATA4) | _BV(LCD_SCLK) | _BV(LCD_OE) | _BV(LCD_COM));
cbi(LCD_PORT, LCD_SCLK);
cbi(LCD_PORT, LCD_OE);
//
KEY1_DDR &= ~(_BV(KEY1));
KEY1_PORT |= _BV(KEY1);
KEY2_DDR &= ~(_BV(KEY2));
KEY2_PORT |= _BV(KEY2);
// ds1307
DS1307SQ_DDR &= ~_BV(DS1307SQ);
DS1307SQ_PORT |= _BV(DS1307SQ);
PCICR |= _BV(DS1307SQ_INT);
DS1307SQ_MSK |= _BV(DS1307SQ);
sei();
// ds1307 , ,
// , -
// setDS3231time(30,40,21,6,11,3,18);
while(1)
{
byte need_render = 0;
byte need_date_set = 0;
// ds1307,
//
if (need_render_int) {
byte rc;
if (mode == MODE_MAIN) {
rc = readDS3231time_hms(&second, &minute, &hour);
} else {
rc = readDS3231time(&second, &minute, &hour, &dayOfWeek, &dayOfMonth, &month, &year);
}
if ( ! rc && twi_problems) {
twi_problems -= 1;
} else {
twi_problems += rc;
}
need_render = 1;
need_render_int = 0;
}
// 1/10
if ( ! cycle_count_10) {
even_10 = ! even_10;
// ,
if (mode_timeout > 0) {
mode_timeout -= 1;
}
// ,
if (mode != MODE_MAIN && ! mode_timeout) {
mode = MODE_MAIN;
need_render = 1;
}
// , 10
if (mode == MODE_SET_MINUTE || mode == MODE_SET_HOUR || mode == MODE_SET_DAY || mode == MODE_SET_MONTH || mode == MODE_SET_YEAR) {
need_render = 1;
}
//
byte key1_down = (KEY1_PIN & _BV(KEY1)) ? 0 : 1;
byte key2_down = (KEY2_PIN & _BV(KEY2)) ? 0 : 1;
if (key1_down || key2_down || key1_press || key2_press) {
need_render = 1;
}
if (key1_down && key1_press) {
key1_time += 1;
}
if (key2_down && key2_press) {
key2_time += 1;
}
//
if (key1_down && ! key1_press) {
if (mode == MODE_SET_MINUTE) {
mode = MODE_SET_HOUR;
mode_timeout = MODE_TIMEOUT_SET;
} else if (mode == MODE_SET_HOUR) {
mode = MODE_SET_DAY;
mode_timeout = MODE_TIMEOUT_SET;
} else if (mode == MODE_SET_DAY) {
mode = MODE_SET_MONTH;
mode_timeout = MODE_TIMEOUT_SET;
} else if (mode == MODE_SET_MONTH) {
mode = MODE_SET_YEAR;
mode_timeout = MODE_TIMEOUT_SET;
} else if (mode == MODE_SET_YEAR) {
mode = MODE_MAIN;
} else if (mode == MODE_MAIN) {
mode = MODE_SECOND;
mode_timeout = MODE_TIMEOUT_SET;
} else if (mode == MODE_SECOND) {
mode = MODE_MAIN;
mode_timeout = 0;
}
} else if ( ! key1_down && key1_press) {
if (key1_time >= KEY_TIMEOUT) {
} else {
}
} else if (key1_down && key1_press) {
if (key1_time >= KEY_TIMEOUT) {
if (mode == MODE_MAIN || mode == MODE_SECOND) {
mode = MODE_SET_MINUTE;
mode_timeout = MODE_TIMEOUT_SET;
}
} else {
}
}
if (key2_down && ! key2_press) {
if (mode == MODE_MAIN) {
mode = MODE_CALENDAR;
mode_timeout = MODE_TIMEOUT;
} else if (mode == MODE_CALENDAR) {
mode = MODE_YEAR;
mode_timeout = MODE_TIMEOUT;
} else if (mode == MODE_YEAR) {
mode = MODE_MAIN;
mode_timeout = 0;
} else if (mode == MODE_SET_MINUTE) {
minute += 1;
mode_timeout = MODE_TIMEOUT_SET;
need_date_set = 1;
} else if (mode == MODE_SET_HOUR) {
hour += 1;
mode_timeout = MODE_TIMEOUT_SET;
need_date_set = 1;
} else if (mode == MODE_SET_DAY) {
dayOfMonth += 1;
mode_timeout = MODE_TIMEOUT_SET;
need_date_set = 1;
} else if (mode == MODE_SET_MONTH) {
month += 1;
mode_timeout = MODE_TIMEOUT_SET;
need_date_set = 1;
} else if (mode == MODE_SET_YEAR) {
year += 1;
mode_timeout = MODE_TIMEOUT_SET;
need_date_set = 1;
} else if (mode == MODE_SECOND) {
second = 0;
need_date_set = 1;
mode_timeout = MODE_TIMEOUT_SET;
}
} else if ( ! key2_down && key2_press) {
if (key2_time >= KEY_TIMEOUT) {
} else {
}
} else if (key2_down && key2_press) {
if (key2_time >= KEY_TIMEOUT) {
if (mode == MODE_SET_MINUTE) {
minute += 1;
mode_timeout = MODE_TIMEOUT_SET;
need_date_set = 1;
} else if (mode == MODE_SET_HOUR) {
hour += 1;
mode_timeout = MODE_TIMEOUT_SET;
need_date_set = 1;
} else if (mode == MODE_SET_DAY) {
dayOfMonth += 1;
mode_timeout = MODE_TIMEOUT_SET;
need_date_set = 1;
} else if (mode == MODE_SET_MONTH) {
month += 1;
mode_timeout = MODE_TIMEOUT_SET;
need_date_set = 1;
} else if (mode == MODE_SET_YEAR) {
year += 1;
mode_timeout = MODE_TIMEOUT_SET;
need_date_set = 1;
}
} else {
}
}
key1_press = key1_down;
if ( ! key1_press) {
key1_time = 0;
}
key2_press = key2_down;
if ( ! key2_press) {
key2_time = 0;
}
}
if (need_date_set) {
//
// ds1307 ,
// , ,
if (minute > 59) {
minute = 0;
}
if (hour > 23) {
hour = 0;
}
if (dayOfMonth > 31) {
dayOfMonth = 1;
}
if (month > 12) {
month = 1;
}
if (year > 99) {
year = 0;
}
// ds1307
setDS3231time(second, minute, hour, dayOfWeek, dayOfMonth, month, year);
}
// ,
if (need_render) {
do_render();
}
//
cli();
lcd_refresh();
sei();
_delay_ms(10);
cycle_count_10 += 1;
if (cycle_count_10 >= 10) {
cycle_count_10 = 0;
}
}
return 0;
}
// -
byte decToBcd(byte val)
{
return( (val/10*16) + (val%10) );
}
byte bcdToDec(byte val)
{
return( (val/16*10) + (val%16) );
}
// ds1307
void setDS3231time(byte second,
byte minute,
byte hour,
byte dayOfWeek,
byte dayOfMonth,
byte month,
byte year)
{
twi_write((uint8_t) DS3231_I2C_ADDRESS, (uint8_t) 0, (uint8_t) decToBcd(second));
twi_write((uint8_t) DS3231_I2C_ADDRESS, (uint8_t) 1, (uint8_t) decToBcd(minute));
twi_write((uint8_t) DS3231_I2C_ADDRESS, (uint8_t) 2, (uint8_t) decToBcd(hour));
twi_write((uint8_t) DS3231_I2C_ADDRESS, (uint8_t) 3, (uint8_t) decToBcd(dayOfWeek));
twi_write((uint8_t) DS3231_I2C_ADDRESS, (uint8_t) 4, (uint8_t) decToBcd(dayOfMonth));
twi_write((uint8_t) DS3231_I2C_ADDRESS, (uint8_t) 5, (uint8_t) decToBcd(month));
twi_write((uint8_t) DS3231_I2C_ADDRESS, (uint8_t) 6, (uint8_t) decToBcd(year));
// SQ 1Hz
// , ds1307
// 8kHz
twi_write((uint8_t) DS3231_I2C_ADDRESS, (uint8_t) 7, (uint8_t) 0b00010000);
}
// ds1307
byte readDS3231time(byte *second,
byte *minute,
byte *hour,
byte *dayOfWeek,
byte *dayOfMonth,
byte *month,
byte *year)
{
byte rc = twi_read(DS3231_I2C_ADDRESS, 0, 7);
if (rc) return 1;
*second = bcdToDec(twi_receive() & 0x7f);
*minute = bcdToDec(twi_receive());
*hour = bcdToDec(twi_receive() & 0x3f);
*dayOfWeek = bcdToDec(twi_receive());
*dayOfMonth = bcdToDec(twi_receive());
*month = bcdToDec(twi_receive());
*year = bcdToDec(twi_receive());
}
// , , ,
byte readDS3231time_hms(byte *second, byte *minute, byte *hour) {
byte rc = twi_read(DS3231_I2C_ADDRESS, 0, 3);
if (rc) return 1;
*second = bcdToDec(twi_receive() & 0x7f);
*minute = bcdToDec(twi_receive());
*hour = bcdToDec(twi_receive() & 0x3f);
}
/*
* , , : http://dsscircuits.com/articles/arduino-i2c-master-library
* , 4k .
*/
/*
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#define START 0x08
#define REPEATED_START 0x10
#define MT_SLA_ACK 0x18
#define MT_SLA_NACK 0x20
#define MT_DATA_ACK 0x28
#define MT_DATA_NACK 0x30
#define MR_SLA_ACK 0x40
#define MR_SLA_NACK 0x48
#define MR_DATA_ACK 0x50
#define MR_DATA_NACK 0x58
#define LOST_ARBTRTN 0x38
#define TWI_STATUS (TWSR & 0xF8)
#define SLA_W(address) (address << 1)
#define SLA_R(address) ((address << 1) + 0x01)
#define MAX_BUFFER_SIZE 32
uint8_t twi_bytesAvailable = 0;
uint8_t twi_bufferIndex = 0;
uint8_t twi_totalBytes = 0;
uint16_t twi_timeOutDelay = 0;
uint8_t twi_returnStatus;
uint8_t twi_nack;
uint8_t twi_data[MAX_BUFFER_SIZE];
void twi_begin()
{
sbi(PORTC, 4);
sbi(PORTC, 5);
cbi(TWSR, TWPS0);
cbi(TWSR, TWPS1);
TWBR = ((F_CPU / 100000) - 16) / 2;
TWCR = _BV(TWEN) | _BV(TWEA);
}
uint8_t twi_read(uint8_t address, uint8_t registerAddress, uint8_t numberBytes)
{
twi_bytesAvailable = 0;
twi_bufferIndex = 0;
if(numberBytes == 0){numberBytes++;}
twi_nack = numberBytes - 1;
twi_returnStatus = 0;
twi_returnStatus = twi_start();
if(twi_returnStatus){return(twi_returnStatus);}
twi_returnStatus = twi_sendAddress(SLA_W(address));
if(twi_returnStatus)
{
if(twi_returnStatus == 1){return(2);}
return(twi_returnStatus);
}
twi_returnStatus = twi_sendByte(registerAddress);
if(twi_returnStatus)
{
if(twi_returnStatus == 1){return(3);}
return(twi_returnStatus);
}
twi_returnStatus = twi_start();
if(twi_returnStatus)
{
if(twi_returnStatus == 1){return(4);}
return(twi_returnStatus);
}
twi_returnStatus = twi_sendAddress(SLA_R(address));
if(twi_returnStatus)
{
if(twi_returnStatus == 1){return(5);}
return(twi_returnStatus);
}
for(uint8_t i = 0; i < numberBytes; i++)
{
if( i == twi_nack )
{
twi_returnStatus = twi_receiveByte(0);
if(twi_returnStatus == 1){return(6);}
if(twi_returnStatus != MR_DATA_NACK){return(twi_returnStatus);}
}
else
{
twi_returnStatus = twi_receiveByte(1);
if(twi_returnStatus == 1){return(6);}
if(twi_returnStatus != MR_DATA_ACK){return(twi_returnStatus);}
}
twi_data[i] = TWDR;
twi_bytesAvailable = i+1;
twi_totalBytes = i+1;
}
twi_returnStatus = twi_stop();
if(twi_returnStatus)
{
if(twi_returnStatus == 1){return(7);}
return(twi_returnStatus);
}
return(twi_returnStatus);
}
uint8_t twi_write(uint8_t address, uint8_t registerAddress, uint8_t data)
{
twi_returnStatus = 0;
twi_returnStatus = twi_start();
if(twi_returnStatus){return(twi_returnStatus);}
twi_returnStatus = twi_sendAddress(SLA_W(address));
if(twi_returnStatus)
{
if(twi_returnStatus == 1){return(2);}
return(twi_returnStatus);
}
twi_returnStatus = twi_sendByte(registerAddress);
if(twi_returnStatus)
{
if(twi_returnStatus == 1){return(3);}
return(twi_returnStatus);
}
twi_returnStatus = twi_sendByte(data);
if(twi_returnStatus)
{
if(twi_returnStatus == 1){return(3);}
return(twi_returnStatus);
}
twi_returnStatus = twi_stop();
if(twi_returnStatus)
{
if(twi_returnStatus == 1){return(7);}
return(twi_returnStatus);
}
return(twi_returnStatus);
}
uint8_t twi_receive()
{
twi_bufferIndex = twi_totalBytes - twi_bytesAvailable;
if(!twi_bytesAvailable)
{
twi_bufferIndex = 0;
return(0);
}
twi_bytesAvailable--;
return(twi_data[twi_bufferIndex]);
}
uint8_t twi_start()
{
unsigned long startingTime = millis();
TWCR = (1<<TWINT)|(1<<TWSTA)|(1<<TWEN);
while (!(TWCR & (1<<TWINT)))
{
if(!twi_timeOutDelay){continue;}
if((millis() - startingTime) >= twi_timeOutDelay)
{
twi_lockUp();
return(1);
}
}
if ((TWI_STATUS == START) || (TWI_STATUS == REPEATED_START))
{
return(0);
}
if (TWI_STATUS == LOST_ARBTRTN)
{
uint8_t bufferedStatus = TWI_STATUS;
twi_lockUp();
return(bufferedStatus);
}
return(TWI_STATUS);
}
uint8_t twi_sendAddress(uint8_t i2cAddress)
{
TWDR = i2cAddress;
unsigned long startingTime = millis();
TWCR = (1<<TWINT) | (1<<TWEN);
while (!(TWCR & (1<<TWINT)))
{
if(!twi_timeOutDelay){continue;}
if((millis() - startingTime) >= twi_timeOutDelay)
{
twi_lockUp();
return(1);
}
}
if ((TWI_STATUS == MT_SLA_ACK) || (TWI_STATUS == MR_SLA_ACK))
{
return(0);
}
uint8_t bufferedStatus = TWI_STATUS;
if ((TWI_STATUS == MT_SLA_NACK) || (TWI_STATUS == MR_SLA_NACK))
{
twi_stop();
return(bufferedStatus);
}
else
{
twi_lockUp();
return(bufferedStatus);
}
}
uint8_t twi_sendByte(uint8_t i2cData)
{
TWDR = i2cData;
unsigned long startingTime = millis();
TWCR = (1<<TWINT) | (1<<TWEN);
while (!(TWCR & (1<<TWINT)))
{
if(!twi_timeOutDelay){continue;}
if((millis() - startingTime) >= twi_timeOutDelay)
{
twi_lockUp();
return(1);
}
}
if (TWI_STATUS == MT_DATA_ACK)
{
return(0);
}
uint8_t bufferedStatus = TWI_STATUS;
if (TWI_STATUS == MT_DATA_NACK)
{
twi_stop();
return(bufferedStatus);
}
else
{
twi_lockUp();
return(bufferedStatus);
}
}
uint8_t twi_receiveByte(uint8_t ack)
{
unsigned long startingTime = millis();
if(ack)
{
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA);
}
else
{
TWCR = (1<<TWINT) | (1<<TWEN);
}
while (!(TWCR & (1<<TWINT)))
{
if(!twi_timeOutDelay){continue;}
if((millis() - startingTime) >= twi_timeOutDelay)
{
twi_lockUp();
return(1);
}
}
if (TWI_STATUS == LOST_ARBTRTN)
{
uint8_t bufferedStatus = TWI_STATUS;
twi_lockUp();
return(bufferedStatus);
}
return(TWI_STATUS);
}
uint8_t twi_stop()
{
unsigned long startingTime = millis();
TWCR = (1<<TWINT)|(1<<TWEN)| (1<<TWSTO);
while ((TWCR & (1<<TWSTO)))
{
if(!twi_timeOutDelay){continue;}
if((millis() - startingTime) >= twi_timeOutDelay)
{
twi_lockUp();
return(1);
}
}
return(0);
}
void twi_lockUp()
{
TWCR = 0;
TWCR = _BV(TWEN) | _BV(TWEA);
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Source: https://habr.com/ru/post/410899/
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