rewrite with minimal hd444780/modbus example

i2c.h

@@ -0,0 +1,26 @@
+/*
+ * i2c.h
+ *
+ * Created: 20.01.2018 12:51:11
+ *  Author: Ulrich
+ */ 
+
+#ifndef I2C_H_
+	#define I2C_H_
+
+	#include <avr/io.h>
+	#include <util/delay.h>
+	
+	//I2C
+	#define SDA_PIN			PC4 //PIN am Atmel
+	#define SCL_PIN			PC5 //PIN am Atmel
+	#define I2C_PORT		PORTC //PORT am Atmel
+	#define SCL_CLOCK		100000UL
+
+	void i2c_init(void);
+	uint8_t i2c_start (uint8_t);
+	uint8_t i2c_byte (uint8_t);  
+	uint8_t i2c_readNak(void);
+	void i2c_stop (void);
+
+#endif /* I2C_H_ */