1 | #include <LPC21xx.H>
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2 | #include <stdarg.h>
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3 |
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4 | void I2CISR (void) __irq ;
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5 | //I2C interrupt
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6 | void I2CTransferByte(unsigned Addr,unsigned Data); //Background call to start master send and receive byte transfers
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7 |
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8 | unsigned I2CAdresse;
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9 | unsigned I2CData;
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10 |
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11 |
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12 | int main(void)
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13 | {
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14 |
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15 | VICVectCntl1 = 0x00000029; //select a priority slot for a given interrupt
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16 | VICVectAddr1 = (unsigned)I2CISR; //pass the address of the IRQ into the VIC slot
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17 | VICIntEnable = 0x00000200; //enable interrupt
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18 |
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19 | PINSEL0 = 0x50; //Switch GPIO to I2C pins
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20 |
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21 |
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22 | // Initial I2C Data Rate = 100KHz(VPB=29.4912MHz)
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23 | // I2C Data Rate = 29.4912MHz / 294
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24 | // = 100.31KHz
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25 | I2SCLH = 0x00000093; // Clock High = 147
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26 | I2SCLL = 0x00000093; // Clock Low = 147
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27 |
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28 |
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29 |
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30 | while(1)
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31 | {
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32 | //Display löschen
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33 | I2CTransferByte(0xDE,0x11); //DC1
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34 | I2CTransferByte(0xDE,0x03); //lengh
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35 | I2CTransferByte(0xDE,0x1B); //ESC
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36 | I2CTransferByte(0xDE,0x44); //D
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37 | I2CTransferByte(0xDE,0x4C); //L
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38 | I2CTransferByte(0xDE,0x11 + 0x03 + 0x1B+ 'D' + 'L');
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39 | }
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40 | }
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41 |
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42 |
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43 | void I2CTransferByte(unsigned Addr,unsigned Data)
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44 | {
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45 | I2CAdresse = Addr; //Place address and data in Globals to be used by
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46 | //the interrupt
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47 | I2CData = Data;
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48 | I2CONCLR = 0x0000006C; //Clear all I2C settings
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49 | I2CONSET = 0x00000040; //Enable the I2C interface
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50 | I2CONSET = 0x00000020; //Start condition
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51 | }
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52 |
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53 |
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54 | void I2CISR (void) __irq //I2C interrupt routine
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55 | {
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56 |
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57 | switch (I2STAT) //Read result code and switch to next action
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58 | {
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59 | // Start and Send byte conditions
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60 |
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61 | case ( 0x08): //Start bit
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62 | I2CONCLR = 0x20; //Clear start bit
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63 | I2DAT = I2CAdresse; //Send address and write bit
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64 | break;
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65 |
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66 | case (0x18): //Slave address+W, ACK
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67 | I2DAT = I2CData; //Write Mem,ory start address to tx register
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68 | break;
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69 |
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70 | case (0x20): //Salve address +W, Not ACK
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71 | I2DAT = I2CAdresse; //Resend address and write bi
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72 | break;
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73 |
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74 | case (0x28):
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75 | I2CONSET = 0x10; //Stop condition
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76 | break;
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77 |
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78 | case (0x30) : //Data sent, NOT Ack
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79 | I2DAT = I2CData; //Write data to tx register
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80 | break;
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81 |
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82 |
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83 | //Receive byte conditions
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84 |
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85 | case (0x40) : //Slave Address +R, ACK
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86 | I2CONSET = 0x04; //Enable ACK for data byte
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87 | break;
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88 |
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89 | case (0x48) : //Slave Address +R, Not Ack
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90 | I2CONSET = 0x20; //Resend Start condition
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91 | break;
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92 |
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93 | case (0x50) : //Data Received, ACK
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94 |
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95 | I2CONSET = 0x10; //Stop condition
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96 | //Signal end of I2C activity
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97 |
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98 | break;
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99 |
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100 | case (0x58): //Data Received, Not Ack
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101 | I2CONSET = 0x20; // Resend Start condition
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102 | break;
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103 |
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104 | default :
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105 | break;
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106 |
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107 | }
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108 |
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109 | I2CONCLR = 0x08; //Clear I2C interrupt flag
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110 | VICVectAddr = 0x00000000; //Clear interrupt in
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111 |
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112 | }
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