diff --git a/extras/pcf8574/pcf8574.c b/extras/pcf8574/pcf8574.c
index 04910a8..8add3c2 100644
--- a/extras/pcf8574/pcf8574.c
+++ b/extras/pcf8574/pcf8574.c
@@ -17,52 +17,52 @@
 
 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;
+    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;
+    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;
+    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;
+    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;
+    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();
+    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);
+    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);
+    uint8_t bit = (uint8_t)value << num;
+    uint8_t mask = ~(1 << num);
+    pcf8574_port_write (addr, (pcf8574_port_read(addr) & mask) | bit);
 }
diff --git a/extras/pcf8574/pcf8574.h b/extras/pcf8574/pcf8574.h
index b2ef9e1..ee67ce2 100644
--- a/extras/pcf8574/pcf8574.h
+++ b/extras/pcf8574/pcf8574.h
@@ -14,6 +14,7 @@
  */
 /**
  * \file Driver for PCF8574 compartible remote 8-bit I/O expanders for I2C-bus
+ * \author Ruslan V. Uss
  */
 #ifndef PCF8574_PCF8574_H_
 #define PCF8574_PCF8574_H_