esp-open-rtos/extras/pcf8574/pcf8574.c
2016-03-02 02:19:46 +05:00

54 lines
1.2 KiB
C

#include "pcf8574.h"
#include <i2c/i2c.h>
uint8_t pcf8574_port_read(uint8_t addr)
{
i2c_start();
uint8_t res = i2c_write((addr << 1) | 1) ? i2c_read(1) : 0;
i2c_stop();
return res;
}
size_t pcf8574_port_read_buf(uint8_t addr, void *buf, size_t len)
{
if (!len || !buf) return 0;
uint8_t *_buf = (uint8_t *)buf;
i2c_start();
if (!i2c_write((addr << 1) | 1)) return 0;
for (size_t i = 0; i < len; i++)
*_buf++ = i2c_read(i == len - 1);
i2c_stop();
return len;
}
size_t pcf8574_port_write_buf(uint8_t addr, void *buf, size_t len)
{
if (!len || !buf) return 0;
uint8_t *_buf = (uint8_t *)buf;
i2c_start();
if (!i2c_write(addr << 1)) return 0;
for (size_t i = 0; i < len; i++)
i2c_write(*_buf++);
return len;
}
void pcf8574_port_write(uint8_t addr, uint8_t value)
{
i2c_start();
if (i2c_write(addr << 1)) i2c_write(value);
i2c_stop();
}
bool pcf8574_gpio_read(uint8_t addr, uint8_t num)
{
return (bool)((pcf8574_port_read(addr) >> num) & 1);
}
void pcf8574_gpio_write(uint8_t addr, uint8_t num, bool value)
{
uint8_t bit = (uint8_t)value << num;
uint8_t mask = ~(1 << num);
pcf8574_port_write (addr, (pcf8574_port_read(addr) & mask) | bit);
}