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#include "driver/soft_i2c.h"
#include "driver/gpio.h"
signed char SoftI2C::setup()
{
gpio.write(sda, 0);
gpio.write(scl, 0);
return 0;
}
void SoftI2C::start()
{
gpio.input(sda);
gpio.input(scl);
//
gpio.output(sda);
//
gpio.output(scl);
}
void SoftI2C::stop()
{
gpio.output(sda);
//
gpio.input(scl);
//
gpio.input(sda);
}
bool SoftI2C::tx(unsigned char byte)
{
unsigned char got_ack = 0;
for (unsigned char i = 0; i <= 8; i++) {
if ((byte & 0x80) || (i == 8)) {
gpio.input(sda);
} else {
gpio.output(sda);
}
byte <<= 1;
//
gpio.input(scl);
//
if (i == 8) {
if (!gpio.read(sda)) {
got_ack = 1;
}
}
gpio.output(scl);
//
}
return got_ack;
}
unsigned char SoftI2C::rx(bool send_ack)
{
unsigned char byte = 0;
gpio.input(sda);
for (unsigned char i = 0; i <= 8; i++) {
//
gpio.input(scl);
//
if ((i < 8) && gpio.read(sda)) {
byte |= 1 << (7 - i);
}
//
gpio.output(scl);
//
if ((i == 7) && send_ack) {
gpio.output(sda);
} else if ((i == 8) && send_ack) {
gpio.input(sda);
}
}
return byte;
}
void SoftI2C::scan(unsigned int *results)
{
unsigned char i2caddr;
for (unsigned char address = 0; address < 128; address++) {
i2caddr = (address << 1) | 1;
start();
if (tx(i2caddr)) {
results[address / (8 * sizeof(unsigned int))] |= 1 << (address % (8 * sizeof(unsigned int)));
}
}
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] = rx((i < rx_len) * 1);
}
}
stop();
return 0;
}
SoftI2C i2c(GPIO::p1_6, GPIO::p1_7);
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