diff --git a/i2c.c b/i2c.c
new file mode 100644
index 0000000..efa70d2
--- /dev/null
+++ b/i2c.c
@@ -0,0 +1,65 @@
+//
+//  i2c.c
+//  i2c
+//
+//  Created by Michael Köhler on 09.10.17.
+//
+//
+
+#include "i2c.h"
+
+#if defined(__AVR_ATmega328P__) || defined(__AVR_ATmega168P__) || defined(__AVR_ATmega168PA__) || defined(__AVR_ATmega88P__) || defined(__AVR_ATmega48P__) || defined(__AVR_ATmega1284P__)
+#if PSC_I2C != 1 && PSC_I2C != 4 && PSC_I2C != 16 && PSC_I2C != 64
+#error "Wrong prescaler for TWI !"
+#elif SET_TWBR < 0 || SET_TWBR > 255
+#error "TWBR out of range, change PSC_I2C or F_I2C !"
+#endif
+void i2c_init(void){
+    // set clock
+    switch (PSC_I2C) {
+        case 4:
+            TWSR = 0x1;
+            break;
+        case 16:
+            TWSR = 0x2;
+            break;
+        case 64:
+            TWSR = 0x3;
+            break;
+        default:
+            TWSR = 0x00;
+            break;
+    }
+    TWBR = (uint8_t)SET_TWBR;
+    // enable
+    TWCR = (1 << TWEN);
+}
+void i2c_start(uint8_t i2c_addr){
+    // i2c start
+    TWCR = (1 << TWINT)|(1 << TWSTA)|(1 << TWEN);
+    while((TWCR & (1 << TWINT)) == 0);
+    // send adress
+    TWDR = i2c_addr;
+    TWCR = (1 << TWINT)|( 1 << TWEN);
+    while((TWCR & (1 << TWINT)) == 0);
+}
+void i2c_stop(void){
+    // i2c stop
+    TWCR = (1 << TWINT)|(1 << TWSTO)|(1 << TWEN);
+}
+void i2c_byte(uint8_t byte){
+    TWDR = byte;
+    TWCR = (1 << TWINT)|( 1 << TWEN);
+    while((TWCR & (1 << TWINT)) == 0);
+}
+uint8_t i2c_readAck(void){
+    TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWEA);
+    while ((TWCR & (1<<TWINT)) == 0);
+    return TWDR;
+}
+uint8_t i2c_readNAck(void){
+    TWCR = (1<<TWINT)|(1<<TWEN);
+    while ((TWCR & (1<<TWINT)) == 0);
+    return TWDR;
+}
+#endif
diff --git a/i2c.h b/i2c.h
new file mode 100644
index 0000000..88283a9
--- /dev/null
+++ b/i2c.h
@@ -0,0 +1,28 @@
+//
+//  i2c.h
+//  i2c
+//
+//  Created by Michael Köhler on 09.10.17.
+//
+//
+
+#ifndef i2c_h
+#define i2c_h
+
+/* TODO: setup i2c/twi */
+#define F_I2C			400000UL// clock i2c
+#define PSC_I2C			1		// prescaler i2c
+#define SET_TWBR		(F_CPU/F_I2C-16UL)/(PSC_I2C*2UL)
+
+#include <stdio.h>
+#include <avr/io.h>
+
+void i2c_init(void);				// init hw-i2c
+void i2c_start(uint8_t i2c_addr);	// send i2c_start_condition
+void i2c_stop(void);				// send i2c_stop_condition
+void i2c_byte(uint8_t byte);		// send data_byte
+
+uint8_t i2c_readAck(void);          // read byte with ACK
+uint8_t i2c_readNAck(void);         // read byte with NACK
+
+#endif /* i2c_h */
diff --git a/lcd.c b/lcd.c
new file mode 100644
index 0000000..ff23915
--- /dev/null
+++ b/lcd.c
@@ -0,0 +1,344 @@
+/*
+ * This file is part of lcd library for ssd1306/sh1106 oled-display.
+ *
+ * lcd library for ssd1306/sh1106 oled-display is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or any later version.
+ *
+ * lcd library for ssd1306/sh1106 oled-display is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Foobar.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Diese Datei ist Teil von lcd library for ssd1306/sh1106 oled-display.
+ *
+ * lcd library for ssd1306/sh1106 oled-display ist Freie Software: Sie können es unter den Bedingungen
+ * der GNU General Public License, wie von der Free Software Foundation,
+ * Version 3 der Lizenz oder jeder späteren
+ * veröffentlichten Version, weiterverbreiten und/oder modifizieren.
+ *
+ * lcd library for ssd1306/sh1106 oled-display wird in der Hoffnung, dass es nützlich sein wird, aber
+ * OHNE JEDE GEWÄHRLEISTUNG, bereitgestellt; sogar ohne die implizite
+ * Gewährleistung der MARKTFÄHIGKEIT oder EIGNUNG FÜR EINEN BESTIMMTEN ZWECK.
+ * Siehe die GNU General Public License für weitere Details.
+ *
+ * Sie sollten eine Kopie der GNU General Public License zusammen mit diesem
+ * Programm erhalten haben. Wenn nicht, siehe <http://www.gnu.org/licenses/>.
+ *
+ *  lcd.h
+ *
+ *  Created by Michael Köhler on 22.12.16.
+ *  Copyright 2016 Skie-Systems. All rights reserved.
+ *
+ *  lib for OLED-Display with ssd1306/sh1106-Controller
+ *  first dev-version only for I2C-Connection
+ *  at ATMega328P like Arduino Uno
+ ****************************************************
+ *  For other Atmegas/Attinys: GFX-Lib needs a
+ *  minimum of 1029 byte SRAM!
+ ****************************************************
+ *
+ */
+/* Standard ASCII 6x8 font */
+
+#include "lcd.h"
+#include <avr/interrupt.h>
+#include <string.h>
+
+static const uint8_t ssd1306oled_font6x8 [] PROGMEM = {
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // sp
+    0x00, 0x00, 0x00, 0x2f, 0x00, 0x00, // !
+    0x00, 0x00, 0x07, 0x00, 0x07, 0x00, // "
+    0x00, 0x14, 0x7f, 0x14, 0x7f, 0x14, // #
+    0x00, 0x24, 0x2a, 0x7f, 0x2a, 0x12, // $
+    0x00, 0x62, 0x64, 0x08, 0x13, 0x23, // %
+    0x00, 0x36, 0x49, 0x55, 0x22, 0x50, // &
+    0x00, 0x00, 0x05, 0x03, 0x00, 0x00, // '
+    0x00, 0x00, 0x1c, 0x22, 0x41, 0x00, // (
+    0x00, 0x00, 0x41, 0x22, 0x1c, 0x00, // )
+    0x00, 0x14, 0x08, 0x3E, 0x08, 0x14, // *
+    0x00, 0x08, 0x08, 0x3E, 0x08, 0x08, // +
+    0x00, 0x00, 0x00, 0xA0, 0x60, 0x00, // ,
+    0x00, 0x08, 0x08, 0x08, 0x08, 0x08, // -
+    0x00, 0x00, 0x60, 0x60, 0x00, 0x00, // .
+    0x00, 0x20, 0x10, 0x08, 0x04, 0x02, // /
+    0x00, 0x3E, 0x51, 0x49, 0x45, 0x3E, // 0
+    0x00, 0x00, 0x42, 0x7F, 0x40, 0x00, // 1
+    0x00, 0x42, 0x61, 0x51, 0x49, 0x46, // 2
+    0x00, 0x21, 0x41, 0x45, 0x4B, 0x31, // 3
+    0x00, 0x18, 0x14, 0x12, 0x7F, 0x10, // 4
+    0x00, 0x27, 0x45, 0x45, 0x45, 0x39, // 5
+    0x00, 0x3C, 0x4A, 0x49, 0x49, 0x30, // 6
+    0x00, 0x01, 0x71, 0x09, 0x05, 0x03, // 7
+    0x00, 0x36, 0x49, 0x49, 0x49, 0x36, // 8
+    0x00, 0x06, 0x49, 0x49, 0x29, 0x1E, // 9
+    0x00, 0x00, 0x36, 0x36, 0x00, 0x00, // :
+    0x00, 0x00, 0x56, 0x36, 0x00, 0x00, // ;
+    0x00, 0x08, 0x14, 0x22, 0x41, 0x00, // <
+    0x00, 0x14, 0x14, 0x14, 0x14, 0x14, // =
+    0x00, 0x00, 0x41, 0x22, 0x14, 0x08, // >
+    0x00, 0x02, 0x01, 0x51, 0x09, 0x06, // ?
+    0x00, 0x32, 0x49, 0x59, 0x51, 0x3E, // @
+    0x00, 0x7C, 0x12, 0x11, 0x12, 0x7C, // A
+    0x00, 0x7F, 0x49, 0x49, 0x49, 0x36, // B
+    0x00, 0x3E, 0x41, 0x41, 0x41, 0x22, // C
+    0x00, 0x7F, 0x41, 0x41, 0x22, 0x1C, // D
+    0x00, 0x7F, 0x49, 0x49, 0x49, 0x41, // E
+    0x00, 0x7F, 0x09, 0x09, 0x09, 0x01, // F
+    0x00, 0x3E, 0x41, 0x49, 0x49, 0x7A, // G
+    0x00, 0x7F, 0x08, 0x08, 0x08, 0x7F, // H
+    0x00, 0x00, 0x41, 0x7F, 0x41, 0x00, // I
+    0x00, 0x20, 0x40, 0x41, 0x3F, 0x01, // J
+    0x00, 0x7F, 0x08, 0x14, 0x22, 0x41, // K
+    0x00, 0x7F, 0x40, 0x40, 0x40, 0x40, // L
+    0x00, 0x7F, 0x02, 0x0C, 0x02, 0x7F, // M
+    0x00, 0x7F, 0x04, 0x08, 0x10, 0x7F, // N
+    0x00, 0x3E, 0x41, 0x41, 0x41, 0x3E, // O
+    0x00, 0x7F, 0x09, 0x09, 0x09, 0x06, // P
+    0x00, 0x3E, 0x41, 0x51, 0x21, 0x5E, // Q
+    0x00, 0x7F, 0x09, 0x19, 0x29, 0x46, // R
+    0x00, 0x46, 0x49, 0x49, 0x49, 0x31, // S
+    0x00, 0x01, 0x01, 0x7F, 0x01, 0x01, // T
+    0x00, 0x3F, 0x40, 0x40, 0x40, 0x3F, // U
+    0x00, 0x1F, 0x20, 0x40, 0x20, 0x1F, // V
+    0x00, 0x3F, 0x40, 0x38, 0x40, 0x3F, // W
+    0x00, 0x63, 0x14, 0x08, 0x14, 0x63, // X
+    0x00, 0x07, 0x08, 0x70, 0x08, 0x07, // Y
+    0x00, 0x61, 0x51, 0x49, 0x45, 0x43, // Z
+    0x00, 0x00, 0x7F, 0x41, 0x41, 0x00, // [
+    0x00, 0x55, 0x2A, 0x55, 0x2A, 0x55, // backslash
+    0x00, 0x00, 0x41, 0x41, 0x7F, 0x00, // ]
+    0x00, 0x04, 0x02, 0x01, 0x02, 0x04, // ^
+    0x00, 0x40, 0x40, 0x40, 0x40, 0x40, // _
+    0x00, 0x00, 0x01, 0x02, 0x04, 0x00, // '
+    0x00, 0x20, 0x54, 0x54, 0x54, 0x78, // a
+    0x00, 0x7F, 0x48, 0x44, 0x44, 0x38, // b
+    0x00, 0x38, 0x44, 0x44, 0x44, 0x20, // c
+    0x00, 0x38, 0x44, 0x44, 0x48, 0x7F, // d
+    0x00, 0x38, 0x54, 0x54, 0x54, 0x18, // e
+    0x00, 0x08, 0x7E, 0x09, 0x01, 0x02, // f
+    0x00, 0x18, 0xA4, 0xA4, 0xA4, 0x7C, // g
+    0x00, 0x7F, 0x08, 0x04, 0x04, 0x78, // h
+    0x00, 0x00, 0x44, 0x7D, 0x40, 0x00, // i
+    0x00, 0x40, 0x80, 0x84, 0x7D, 0x00, // j
+    0x00, 0x7F, 0x10, 0x28, 0x44, 0x00, // k
+    0x00, 0x00, 0x41, 0x7F, 0x40, 0x00, // l
+    0x00, 0x7C, 0x04, 0x18, 0x04, 0x78, // m
+    0x00, 0x7C, 0x08, 0x04, 0x04, 0x78, // n
+    0x00, 0x38, 0x44, 0x44, 0x44, 0x38, // o
+    0x00, 0xFC, 0x24, 0x24, 0x24, 0x18, // p
+    0x00, 0x18, 0x24, 0x24, 0x18, 0xFC, // q
+    0x00, 0x7C, 0x08, 0x04, 0x04, 0x08, // r
+    0x00, 0x48, 0x54, 0x54, 0x54, 0x20, // s
+    0x00, 0x04, 0x3F, 0x44, 0x40, 0x20, // t
+    0x00, 0x3C, 0x40, 0x40, 0x20, 0x7C, // u
+    0x00, 0x1C, 0x20, 0x40, 0x20, 0x1C, // v
+    0x00, 0x3C, 0x40, 0x30, 0x40, 0x3C, // w
+    0x00, 0x44, 0x28, 0x10, 0x28, 0x44, // x
+    0x00, 0x1C, 0xA0, 0xA0, 0xA0, 0x7C, // y
+    0x00, 0x44, 0x64, 0x54, 0x4C, 0x44, // z
+    0x00, 0x00, 0x08, 0x77, 0x41, 0x00, // {
+    0x00, 0x00, 0x00, 0x63, 0x00, 0x00, // ¦
+    0x00, 0x00, 0x41, 0x77, 0x08, 0x00, // }
+    0x00, 0x08, 0x04, 0x08, 0x08, 0x04, // ~
+    0x00, 0x3D, 0x40, 0x40, 0x20, 0x7D, // ü
+    0x00, 0x3D, 0x40, 0x40, 0x40, 0x3D, // Ü
+    0x00, 0x21, 0x54, 0x54, 0x54, 0x79, // ä
+    0x00, 0x7D, 0x12, 0x11, 0x12, 0x7D, // Ä
+    0x00, 0x39, 0x44, 0x44, 0x44, 0x39, // ö
+    0x00, 0x3D, 0x42, 0x42, 0x42, 0x3D, // Ö
+    0x00, 0x02, 0x05, 0x02, 0x00, 0x00, // °
+    0x00, 0x7E, 0x01, 0x49, 0x55, 0x73, // ß
+};
+
+const uint8_t init_sequence [] PROGMEM = {	// Initialization Sequence
+    LCD_DISP_OFF,			// Display OFF (sleep mode)
+    0x20, 0b00,		// Set Memory Addressing Mode
+				// 00=Horizontal Addressing Mode; 01=Vertical Addressing Mode;
+				// 10=Page Addressing Mode (RESET); 11=Invalid
+    0xB0,			// Set Page Start Address for Page Addressing Mode, 0-7
+    0xC8,			// Set COM Output Scan Direction
+    0x00,			// --set low column address
+    0x10,			// --set high column address
+    0x40,			// --set start line address
+    0x81, 0x3F,		// Set contrast control register
+    0xA1,			// Set Segment Re-map. A0=address mapped; A1=address 127 mapped.
+    0xA6,			// Set display mode. A6=Normal; A7=Inverse
+    0xA8, 0x3F,		// Set multiplex ratio(1 to 64)
+    0xA4,			// Output RAM to Display
+				// 0xA4=Output follows RAM content; 0xA5,Output ignores RAM content
+    0xD3, 0x00,		// Set display offset. 00 = no offset
+    0xD5,			// --set display clock divide ratio/oscillator frequency
+    0xF0,			// --set divide ratio
+    0xD9, 0x22,		// Set pre-charge period
+    0xDA, 0x12,		// Set com pins hardware configuration
+    0xDB,			// --set vcomh
+    0x20,			// 0x20,0.77xVcc
+    0x8D, 0x14,		// Set DC-DC enable
+    
+    
+};
+
+void lcd_init(uint8_t dispAttr){
+    i2c_init();
+    uint8_t commandSequence[sizeof(init_sequence)+1];
+    for (uint8_t i = 0; i < sizeof (init_sequence); i++) {
+        commandSequence[i] = (pgm_read_byte(&init_sequence[i]));
+    }
+    commandSequence[sizeof(init_sequence)]=(dispAttr);
+    lcd_command(commandSequence, sizeof(commandSequence));
+    lcd_clrscr();
+}
+void lcd_home(void){
+    lcd_gotoxy(0, 0);
+}
+
+void lcd_command(uint8_t cmd[], uint8_t size) {
+    i2c_start(LCD_I2C_ADDR);
+    i2c_byte(0x00);	// 0x00 for command, 0x40 for data
+    for (uint8_t i=0; i<size; i++) {
+        i2c_byte(cmd[i]);
+    }
+    i2c_stop();
+}
+void lcd_data(uint8_t data[], uint16_t size) {
+    i2c_start(LCD_I2C_ADDR);
+    i2c_byte(0x40);	// 0x00 for command, 0x40 for data
+    for (uint8_t i = 0; i<size; i++) {
+        i2c_byte(data[i]);
+    }
+    i2c_stop();
+}
+void lcd_gotoxy(uint8_t x, uint8_t y){
+    if( x > (DISPLAY_WIDTH/6) || y > (DISPLAY_HEIGHT/8-1)) return;// out of display
+    x = x * 6;					// one char: 6 pixel width
+#if defined SSD1306
+    uint8_t commandSequence[] = {0xb0+y, 0x21, x, 0x7f};
+#elif defined SH1106
+    uint8_t commandSequence[] = {0xb0+y, 0x21, 0x00+((2+x) & (0x0f)), 0x10+( ((2+x) & (0xf0)) >> 4 ), 0x7f};
+#endif
+    lcd_command(commandSequence, sizeof(commandSequence));
+}
+void lcd_clrscr(void){
+    uint8_t clearLine[DISPLAY_WIDTH];
+    memset(clearLine, 0x00, DISPLAY_WIDTH);
+    for (uint8_t j = 0; j <= DISPLAY_HEIGHT/8-1; j++){
+        lcd_gotoxy(0,j);
+        lcd_data(clearLine, sizeof(clearLine));
+        
+    }
+    lcd_home();
+}
+
+void lcd_putc(char c){
+    if((c > 127 ||
+        c < 32) &&
+       (c != 'ü' &&
+        c != 'ö' &&
+        c != '°' &&
+        c != 'ä' &&
+        c != 'ß' &&
+        c != 'Ü' &&
+        c != 'Ö' &&
+        c != 'Ä' ) ) return;
+    
+    i2c_start(LCD_I2C_ADDR);
+    i2c_byte(0x40);	// 0x00 for command, 0x40 for data
+    switch (c) {
+        case 'ü':
+            c = 95; // ü
+            for (uint8_t i = 0; i < 6; i++)
+            {
+                i2c_byte(pgm_read_byte(&ssd1306oled_font6x8[c * 6 + i]));	// print font to ram, print 6 columns
+            }
+            break;
+        case 'ö':
+            c = 99; // ö
+            for (uint8_t i = 0; i < 6; i++)
+            {
+                i2c_byte(pgm_read_byte(&ssd1306oled_font6x8[c * 6 + i]));	// print font to ram, print 6 columns
+            }
+            break;
+        case '°':
+            c = 101; // °
+            for (uint8_t i = 0; i < 6; i++)
+            {
+                i2c_byte(pgm_read_byte(&ssd1306oled_font6x8[c * 6 + i]));	// print font to ram, print 6 columns
+            }
+            break;
+        case 'ä':
+            c = 97; // ä
+            for (uint8_t i = 0; i < 6; i++)
+            {
+                i2c_byte(pgm_read_byte(&ssd1306oled_font6x8[c * 6 + i]));	// print font to ram, print 6 columns
+            }
+            break;
+        case 'ß':
+            c = 102; // ß
+            for (uint8_t i = 0; i < 6; i++)
+            {
+                i2c_byte(pgm_read_byte(&ssd1306oled_font6x8[c * 6 + i]));	// print font to ram, print 6 columns
+            }
+            break;
+        case 'Ü':
+            c = 96; // Ü
+            for (uint8_t i = 0; i < 6; i++)
+            {
+                i2c_byte(pgm_read_byte(&ssd1306oled_font6x8[c * 6 + i]));	// print font to ram, print 6 columns
+            }
+            break;
+        case 'Ö':
+            c = 100; // Ö
+            for (uint8_t i = 0; i < 6; i++)
+            {
+                i2c_byte(pgm_read_byte(&ssd1306oled_font6x8[c * 6 + i]));	// print font to ram, print 6 columns
+            }
+            break;
+        case 'Ä':
+            c = 98; // Ä
+            for (uint8_t i = 0; i < 6; i++)
+            {
+                i2c_byte(pgm_read_byte(&ssd1306oled_font6x8[c * 6 + i]));	// print font to ram, print 6 columns
+            }
+            break;
+        default:
+            c -= 32;
+            if( c < 127-32 ) {
+                for (uint8_t i = 0; i < 6; i++)
+                {
+                    i2c_byte(pgm_read_byte(&ssd1306oled_font6x8[c * 6 + i]));	// print font to ram, print 6 columns
+                }
+                //return;
+            }
+            break;
+    }
+    i2c_stop();
+}
+void lcd_puts(const char* s){
+    while (*s) {
+        lcd_putc(*s++);
+    }
+}
+void lcd_puts_p(const char* progmem_s){
+    register uint8_t c;
+    while ((c = pgm_read_byte(progmem_s++))) {
+        lcd_putc(c);
+    }
+}
+void lcd_invert(uint8_t invert){
+    i2c_start(LCD_I2C_ADDR);
+    uint8_t commandSequence[1];
+    if (invert == YES) {
+        commandSequence[0] = 0xA7;
+    } else {
+        commandSequence[0] = 0xA7;
+    }
+    lcd_command(commandSequence, 1);
+}
+void lcd_set_contrast(uint8_t contrast){
+    uint8_t commandSequence[2] = {0x81, contrast};
+    lcd_command(commandSequence, sizeof(commandSequence));
+}
diff --git a/lcd.h b/lcd.h
new file mode 100644
index 0000000..8804dd6
--- /dev/null
+++ b/lcd.h
@@ -0,0 +1,92 @@
+/*
+ * This file is part of lcd library for ssd1306/sh1106 oled-display.
+ *
+ * lcd library for ssd1306/sh1106 oled-display is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or any later version.
+ *
+ * lcd library for ssd1306/sh1106 oled-display is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Foobar.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Diese Datei ist Teil von lcd library for ssd1306/sh1106 oled-display.
+ *
+ * lcd library for ssd1306/sh1106 oled-display ist Freie Software: Sie können es unter den Bedingungen
+ * der GNU General Public License, wie von der Free Software Foundation,
+ * Version 3 der Lizenz oder jeder späteren
+ * veröffentlichten Version, weiterverbreiten und/oder modifizieren.
+ *
+ * lcd library for ssd1306/sh1106 oled-display wird in der Hoffnung, dass es nützlich sein wird, aber
+ * OHNE JEDE GEWÄHRLEISTUNG, bereitgestellt; sogar ohne die implizite
+ * Gewährleistung der MARKTFÄHIGKEIT oder EIGNUNG FÜR EINEN BESTIMMTEN ZWECK.
+ * Siehe die GNU General Public License für weitere Details.
+ *
+ * Sie sollten eine Kopie der GNU General Public License zusammen mit diesem
+ * Programm erhalten haben. Wenn nicht, siehe <http://www.gnu.org/licenses/>.
+ *
+ *  lcd.h
+ *
+ *  Created by Michael Köhler on 22.12.16.
+ *  Copyright 2016 Skie-Systems. All rights reserved.
+ *
+ *  lib for OLED-Display with ssd1306/sh1106-Controller
+ *  first dev-version only for I2C-Connection
+ *  at ATMega328P like Arduino Uno
+ ****************************************************
+ *  For other Atmegas/Attinys: GFX-Lib needs a
+ *  minimum of 1029 byte SRAM!
+ ****************************************************
+ *
+ */
+
+#ifndef LCD_H
+#define LCD_H
+
+#ifndef YES
+#define YES				1
+#define NO				0
+#else
+#error "Check #defines for YES and NO in other sources !"
+#endif
+
+#if (__GNUC__ * 100 + __GNUC_MINOR__) < 303
+#error "This library requires AVR-GCC 3.3 or later, update to newer AVR-GCC compiler !"
+#endif
+
+#include <inttypes.h>
+#include <avr/io.h>
+#include <avr/pgmspace.h>
+#include "i2c.h"
+
+/* TODO: define displaycontroller */
+#define SH1106	// or SSD1306, check datasheet of your display
+
+#define LCD_I2C_ADDR    0x7A
+
+#define LCD_DISP_OFF	0xAE
+#define LCD_DISP_ON		0xAF
+
+#define WHITE			0x01
+#define BLACK			0x00
+
+#define DISPLAY_WIDTH	128
+#define DISPLAY_HEIGHT	64
+#define DISPLAYSIZE		DISPLAY_WIDTH*DISPLAY_HEIGHT/8
+
+void lcd_init(uint8_t dispAttr);
+void lcd_home(void);
+
+void lcd_command(uint8_t cmd[], uint8_t size);				// transmit command to display
+void lcd_data(uint8_t data[], uint16_t size);				// transmit data to display
+void lcd_gotoxy(uint8_t x, uint8_t y);		// set curser at pos x, y. x means character, y means line (page, refer lcd manual)
+void lcd_clrscr(void);						// clear screen
+void lcd_putc(char c);						// print character on screen
+void lcd_puts(const char* s);				// print string, \n-terminated, from ram on screen
+void lcd_puts_p(const char* progmem_s);		// print string from flash on screen
+void lcd_invert(uint8_t invert);			// invert display
+void lcd_set_contrast(uint8_t contrast);	// set contrast for display
+#endif /*  LCD_H  */