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#include "driver/soft_i2c.h"
#include "driver/gpio.h"
#include "arch.h"
#ifdef SOFTI2C_TIMER
#ifdef TIMER_CYCLES
#error "SOFTI2C_TIMER and TIMER_CYCLES are mutually exclusive"
#endif
#include "driver/timer.h"
#endif
#ifdef SOFTI2C_PULLUP
#define SDA_HIGH gpio.input(sda, 1)
#define SDA_LOW gpio.output(sda, 0)
#define SCL_HIGH gpio.input(scl, 1)
#define SCL_LOW gpio.output(scl, 0)
#else
#define SDA_HIGH gpio.input(sda)
#define SDA_LOW gpio.output(sda)
#define SCL_HIGH gpio.input(scl)
#define SCL_LOW gpio.output(scl)
#endif
#ifndef SOFTI2C_TIMER
signed char SoftI2C::setup()
{
SDA_HIGH;
SCL_HIGH;
return 0;
}
void SoftI2C::start()
{
SDA_HIGH;
SCL_HIGH;
//
SDA_LOW;
//
SCL_LOW;
}
void SoftI2C::stop()
{
SCL_LOW;
//
SDA_LOW;
//
SCL_HIGH;
//
SDA_HIGH;
}
bool SoftI2C::tx(unsigned char byte)
{
unsigned char got_ack = 0;
for (unsigned char i = 0; i <= 8; i++) {
if ((byte & 0x80) || (i == 8)) {
SDA_HIGH;
} else {
SDA_LOW;
}
byte <<= 1;
//
SCL_HIGH;
while (!gpio.read(scl)) ;
//
if (i == 8) {
if (!gpio.read(sda)) {
got_ack = 1;
}
}
SCL_LOW;
//
}
return got_ack;
}
unsigned char SoftI2C::rx(bool send_ack)
{
unsigned char byte = 0;
SDA_HIGH;
for (unsigned char i = 0; i <= 8; i++) {
//
SCL_HIGH;
while (!gpio.read(scl)) ;
//
if ((i < 8) && gpio.read(sda)) {
byte |= 1 << (7 - i);
}
//
SCL_LOW;
//
if ((i == 7) && send_ack) {
SDA_LOW;
} else if ((i == 8) && send_ack) {
SDA_HIGH;
}
}
return byte;
}
void SoftI2C::scan(unsigned int *results)
{
unsigned char i2caddr;
for (unsigned char address = 0; address < 128; address++) {
i2caddr = (address << 1) | 0;
start();
if (tx(i2caddr)) {
results[address / (8 * sizeof(unsigned int))] |= 1 << (address % (8 * sizeof(unsigned int)));
stop();
}
}
stop();
}
signed char SoftI2C::xmit(unsigned char address,
unsigned char tx_len, unsigned char *tx_buf,
unsigned char rx_len, unsigned char *rx_buf)
{
unsigned char i;
if (tx_len) {
start();
tx((address << 1) | 0);
for (i = 0; i < tx_len; i++) {
tx(tx_buf[i]);
}
}
if (rx_len) {
start();
tx((address << 1) | 1);
for (i = 1; i <= rx_len; i++) {
rx_buf[i-1] = rx((i < rx_len) * 1);
}
}
stop();
return 0;
}
#else
#ifndef F_I2C
#define F_I2C 100000
#endif
volatile unsigned char timer_done = 0;
inline void await_timer()
{
timer_done = 0;
timer.start(1);
while (!timer_done) {
arch.idle();
}
timer.stop();
}
signed char SoftI2C::setup()
{
SDA_HIGH;
SCL_HIGH;
/*
* I2C frequency is the time between two SCL low->high transitions
* (or high->low, whatever you prefer). For the timer, we need to set the
* time between SCL low->high and the following high->low transition
* (and vice versa), which is twice the desired I2C frequency. Also,
* timer.setup wants kHz and not Hz, so we have
* Timer Freq [kHz] = I2C Freq [Hz] * 2 / 1000
*/
timer.setup(F_I2C / 500);
return 0;
}
void SoftI2C::start()
{
SDA_HIGH;
SCL_HIGH;
await_timer();
SDA_LOW;
await_timer();
SCL_LOW;
await_timer();
}
void SoftI2C::stop()
{
SCL_LOW;
SDA_LOW;
await_timer();
SCL_HIGH;
await_timer();
SDA_HIGH;
}
bool SoftI2C::tx(unsigned char byte)
{
unsigned char got_ack = 0;
for (unsigned char i = 0; i <= 8; i++) {
if ((byte & 0x80) || (i == 8)) {
SDA_HIGH;
} else {
SDA_LOW;
}
byte <<= 1;
SCL_HIGH;
await_timer();
while (!gpio.read(scl)) ;
if (i == 8) {
if (!gpio.read(sda)) {
got_ack = 1;
}
}
SCL_LOW;
await_timer();
}
return got_ack;
}
unsigned char SoftI2C::rx(bool send_ack)
{
unsigned char byte = 0;
SDA_HIGH;
for (unsigned char i = 0; i <= 8; i++) {
SCL_HIGH;
await_timer();
while (!gpio.read(scl)) ;
if ((i < 8) && gpio.read(sda)) {
byte |= 1 << (7 - i);
}
SCL_LOW;
await_timer();
if ((i == 7) && send_ack) {
SDA_LOW;
} else if ((i == 8) && send_ack) {
SDA_HIGH;
}
}
return byte;
}
void SoftI2C::scan(unsigned int *results)
{
unsigned char i2caddr;
for (unsigned char address = 0; address < 128; address++) {
i2caddr = (address << 1) | 0;
start();
if (tx(i2caddr)) {
results[address / (8 * sizeof(unsigned int))] |= 1 << (address % (8 * sizeof(unsigned int)));
stop();
}
}
stop();
}
signed char SoftI2C::xmit(unsigned char address,
unsigned char tx_len, unsigned char *tx_buf,
unsigned char rx_len, unsigned char *rx_buf)
{
unsigned char i;
if (tx_len) {
start();
tx((address << 1) | 0);
for (i = 0; i < tx_len; i++) {
tx(tx_buf[i]);
}
}
if (rx_len) {
start();
tx((address << 1) | 1);
for (i = 1; i <= rx_len; i++) {
rx_buf[i-1] = rx((i < rx_len) * 1);
}
}
stop();
return 0;
}
ON_TIMER_INTERRUPT
{
timer_done = 1;
}
#endif
#ifdef MULTIPASS_ARCH_esp8266
SoftI2C i2c(GPIO::d7, GPIO::d8);
#elif MULTIPASS_ARCH_arduino_nano
SoftI2C i2c(GPIO::pc4, GPIO::pc5);
#elif MULTIPASS_ARCH_blinkenrocket
SoftI2C i2c(GPIO::pc4, GPIO::pc5);
#elif MULTIPASS_ARCH_msp430fr5969lp
SoftI2C i2c(GPIO::p1_6, GPIO::p1_7);
#endif
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