1. #define F_CPU 16000000L
2. #include <avr/io.h>
3. #include<util/delay.h>
4. #define EEDEVADR 0b10100000
5. #define ERROR 1
6. #define SUCCESS (!ERROR)
7.  
8. #define D7 7
9. #define D6 6
10. #define D5 5
11. #define D4 4
12. #define E 3
13. #define RS 2
14. #define RW 1
15. #define SS 2
16. #define MOSI 3
17. #define MISO 4
18. #define SCK 5
19.  
20. void lcd_4bity(unsigned char fourbits)
21. {
22.   PORTD |= (1<<E);
23.   if( fourbits & 0x01) PORTD |= (1<<D4); else PORTD &= ~(1<<D4);
24.   if( fourbits & 0x02) PORTD |= (1<<D5); else PORTD &= ~(1<<D5);
25.   if( fourbits & 0x04) PORTD |= (1<<D6); else PORTD &= ~(1<<D6);
26.   if( fourbits & 0x08) PORTD |= (1<<D7); else PORTD &= ~(1<<D7);
27.   PORTD &= ~(1<<E);
28.  
29. }
30.  
31. void lcd_bajt(unsigned char bajt)
32. {
33.   PORTD |= (1<<E);
34.   lcd_4bity(bajt>>4);
35.   PORTD &= ~(1<<E);
36.   _delay_us(5);
37.   PORTD |= (1<<E);
38.   lcd_4bity(bajt);
39.   PORTD &= ~(1<<E);
40.   _delay_ms(1);
41.  
42. }
43.  
44. void ini_lcd(void)
45. {
46.   lcd_4bity(3);
47.   _delay_ms(10);
48.   lcd_4bity(3);
49.   _delay_ms(1);
50.   lcd_4bity(3);
51.   _delay_ms(1);
52.   lcd_4bity(2);
53.   _delay_ms(1);
54.  
55.   lcd_bajt(28);
56.   _delay_ms(1);
57.   lcd_bajt(20);
58.   _delay_ms(1);
59.   lcd_bajt(12);
60.   _delay_ms(1);
61.   lcd_bajt(6);
62.   _delay_ms(1);
63.   lcd_bajt(1);
64.   _delay_ms(10);
65.   lcd_bajt(128);
66.   _delay_ms(5);
67. }
68.  
69. char aData;
70. char bData;
71.  
72. void SPI_Init(void)
73. {
74.   DDRB |= (1<<SS);
75.   PORTB &= ~(1<<SS);
76.   /* Set MOSI and SCK output, all others input */
77.   DDRB |= (1<<MOSI)|(1<<SCK);
78.   PORTB |= (1<<MISO);
79.   /* Enable SPI, Master, set clock rate fck/16 */
80.   SPCR |= (1<<SPE)|(1<<MSTR)|(1<<SPR1)|(1<<CPHA);
81.  
82. }
83.  
84. char SPI_Transmit(char aData, char bData)
85. {
86.   PORTB |= (1<<SS);
87.   /* Start transmission */
88.   SPDR = aData;
89.   /* Wait for transmission complete */
90.   while(!(SPSR & (1<<SPIF)));
91.   SPDR = bData;
92.   /* Wait for transmission complete */
93.   while(!(SPSR & (1<<SPIF)));
94.   PORTB &= ~(1<<SS);
95.   char z = SPDR;
96.   return(z);
97. }
98.  
99. void setup(void)
100. {
101.   DDRD |= (1<<D7);
102.   DDRD |= (1<<D6);
103.   DDRD |= (1<<D5);
104.   DDRD |= (1<<D4);
105.   DDRD |= (1<<E);
106.   DDRD |= (1<<RS);
107.   DDRD |= (1<<RW);
108.   PORTD &= ~(1<<RW);
109.   PORTD &= ~(1<<RS);  
110.   PORTD &= ~(1<<E);
111.   ini_lcd();
112.   PORTD |= (1<<RS);
113.   _delay_ms(1);
114.  
115. }
116.  
117.  
118.  
119. void loop(void)
120. {
121.   PORTD &= ~(1<<RS);
122.   lcd_bajt(0x80);
123.  
124.   PORTD |= (1<<RS);
125.  
126.  
127.  
128. }
129.  
130. void TWIInit(void)
131. {
132.   //set SCL to 400kHz
133.   TWSR = 0x00;
134.   TWBR = 0x0C;
135.   //enable TWI
136.   TWCR = (1<<TWEN);
137. }
138. void TWIStart(void)
139. {
140.   TWCR =
141.   (1<<TWINT)|(1<<TWSTA)|(1<<TWEN);
142.   while ((TWCR & (1<<TWINT)) == 0);
143. }
144. void TWIStop(void)
145. {
146.   TWCR =
147.   (1<<TWINT)|(1<<TWSTO)|(1<<TWEN);
148. }
149. void TWIWrite(uint8_t u8data)
150. {
151.   TWDR = u8data;
152.   TWCR = (1<<TWINT)|(1<<TWEN);
153.   while ((TWCR & (1<<TWINT)) == 0);
154. }
155. uint8_t TWIReadACK(void)
156. {
157.   TWCR =
158.   (1<<TWINT)|(1<<TWEN)|(1<<TWEA);
159.   while ((TWCR & (1<<TWINT)) == 0);
160.   return TWDR;
161. }
162. uint8_t TWIReadNACK(void)
163. {
164.   TWCR = (1<<TWINT)|(1<<TWEN);
165.   while ((TWCR & (1<<TWINT)) == 0);
166.   return TWDR;
167. }
168. uint8_t TWIGetStatus(void)
169. {
170.   uint8_t status;
171.   //mask status
172.   status = TWSR & 248;
173.   return status;
174. }
175.  
176. uint8_t EEWriteByte(uint16_t u16addr, uint8_t u8data)
177. {
178.   TWIStart();
179.   if (TWIGetStatus() != 8)
180.   return ERROR;
181.   //select device and send A2 A1 A0 address bits
182.   TWIWrite((EEDEVADR)|(uint8_t)((u16addr & 0x0700)>>7));
183.   if (TWIGetStatus() != 24)
184.   return ERROR;
185.   //send the rest of address
186.   TWIWrite((uint8_t)(u16addr));
187.   if (TWIGetStatus() != 40)
188.   return ERROR;
189.   //write byte to eeprom
190.   TWIWrite(u8data);
191.   if (TWIGetStatus() != 40)
192.   return ERROR;
193.   TWIStop();
194.   return SUCCESS;
195. }
196.  
197. uint8_t EEReadByte(uint16_t u16addr)
198. {
199.   //uint8_t databyte;
200.   uint8_t sdata;
201.   TWIStart();
202.   if (TWIGetStatus() != 8)
203.   return ERROR;
204.   //select device and send A2 A1 A0 address bits
205.   TWIWrite((EEDEVADR)|((uint8_t)((u16addr & 0x0700)>>7)));
206.   if (TWIGetStatus() != 36)
207.   return ERROR;
208.   //send the rest of address
209.   TWIWrite((uint8_t)(u16addr));
210.   if (TWIGetStatus() != 40)
211.   return ERROR;
212.   //send start
213.   TWIStart();
214.   if (TWIGetStatus() != 16)
215.   return ERROR;
216.   //select device and send read bit
217.   TWIWrite((EEDEVADR)|((uint8_t)((u16addr & 0x0700)>>7))|1);
218.   if (TWIGetStatus() != 64)
219.   return ERROR;
220.   sdata = TWIReadNACK();
221.   if (TWIGetStatus() != 88)
222.   return ERROR;
223.   TWIStop();
224.   return sdata;
225.   }
226.  
227. int main(void)
228. {
229.   TWIInit();
230.   uint8_t ddata = 0;
231.   uint8_t ew;
232.   setup();
233.   ew= EEWriteByte(5, 'b');
234.   if(ew==SUCCESS)
235.   {
236.     lcd_bajt('S');  
237.   }
238.   else lcd_bajt('E');
239.   _delay_ms(10);
240.   ddata = EEReadByte(5);
241.   if(ew==ERROR)
242.   {
243.   lcd_bajt('E');
244.   }
245.   else lcd_bajt('S');
246.  
247.   lcd_bajt(ddata);
248.   while(1)
249.   loop();
250.   return 0;
251.  
252. }
253.