1 | //////////////////////////////////////////////////////////////////////////
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2 | void init_i2c (void)
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3 | {
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4 | // I2C Disable
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5 | I2C1CONCLR_bit.I2ENC = 1;
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6 |
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7 |
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8 | // CPU Taktteiler fuer I2C1
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9 | // PCLKSEL1_bit.PCLK_I2C1 = 0; // CCLK/4
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10 | PCLKSEL1_bit.PCLK_I2C1 = 1; // CCLK/1
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11 | // PCLKSEL1_bit.PCLK_I2C1 = 2; // CCLK/2
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12 | // PCLKSEL1_bit.PCLK_I2C1 = 3; // CCLK/8
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13 |
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14 |
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15 | // I2C Takt
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16 | // I2C Frequenz = PCLK_I2C / (I2C_I2SCLH + I2C_I2SCLL)
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17 | // Register Wert ist Anzahl von Taktzyklen fuer high- oder low-Time
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18 | I2C1SCLH = 70; // High-Time
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19 | I2C1SCLL = 70; // Low-Time
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20 |
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21 | // Werte muessen groesser gleich 4 sein
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22 | // if (I2C1SCLH < 4 || I2C1SCLL < 4) return;
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23 |
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24 |
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25 | // I2C Configuration Register
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26 | I2C1CONCLR_bit.AAC = 1; // ACK Flag Clear
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27 | I2C1CONCLR_bit.SIC = 1; // Interrupt Flag Clear
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28 | I2C1CONCLR_bit.STAC = 1; // Start Flag Clear
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29 | I2C1CONSET_bit.I2EN = 1; // I2C Enable
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30 | }
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31 | ///////////////////////////////////////////////////////////////////////////
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32 |
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33 | ///////////////////////////////////////////////////////////////////////////
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34 | unsigned char write_i2c (unsigned char addr, unsigned char *data, unsigned char data_cnt)
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35 | {
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36 | unsigned char i;
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37 |
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38 |
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39 | // Start ausgeben
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40 | I2C1CONSET_bit.STA = 1;
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41 |
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42 | // Auf Interrupt warten (Start fertig)
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43 | while (!I2C1CONSET_bit.SI);
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44 | if (I2C1STAT_bit.STATUS != 0x08) return 11;//FALSE;
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45 |
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46 | // Adresse ausgeben
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47 | I2C1DAT = addr<<1; // Write = 8. Bit low
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48 | // Start ruecksetzen
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49 | //I2C1CONCLR_bit.STAC = 1; // Start ruecksetzen
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50 | //I2C1CONCLR_bit.SIC = 1; // Interrupt ruecksetzen
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51 | I2C1CONCLR = 0x20;
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52 | I2C1CONCLR = 0x08;
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53 |
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54 |
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55 | // Auf Interrupt warten (ACK Adresse + Write)
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56 | while (!I2C1CONSET_bit.SI);
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57 | if (I2C1STAT_bit.STATUS != 0x18) return 22;//FALSE;
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58 |
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59 |
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60 | for (i = 0; i < data_cnt; i++)
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61 | {
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62 | // Daten ausgeben
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63 | I2C1DAT = data[i];
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64 | //I2C1CONCLR_bit.SIC = 1; // Interrupt ruecksetzen
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65 | I2C1CONCLR = 0x08;
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66 |
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67 | // Auf Interrupt warten (TX fertig + ACK)
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68 | while (!I2C1CONSET_bit.SI);
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69 | if (I2C1STAT_bit.STATUS != 0x28) return 33;//FALSE;
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70 | }
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71 |
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72 | //I2C1CONCLR_bit.SIC = 1; // Interrupt ruecksetzen
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73 | I2C1CONCLR = 0x08;
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74 |
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75 | // Stop ausgeben
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76 | I2C1CONSET_bit.STO = 1;
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77 |
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78 |
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79 | return TRUE;
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80 | }
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81 | ///////////////////////////////////////////////////////////////////////////
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82 |
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83 | ///////////////////////////////////////////////////////////////////////////
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84 | unsigned char read_i2c (unsigned char addr, unsigned char *data, unsigned char data_cnt)
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85 | {
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86 | unsigned char i;
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87 |
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88 |
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89 | // Start ausgeben
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90 | I2C1CONSET_bit.STA = 1;
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91 |
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92 | // Auf Interrupt warten (Start fertig)
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93 | while (!I2C1CONSET_bit.SI);
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94 | if (I2C1STAT_bit.STATUS != 0x08) return 11;//FALSE;
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95 |
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96 | // Adresse ausgeben
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97 | I2C1DAT = (addr<<1) + 1; // Read = 8. Bit high
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98 | // Start ruecksetzen
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99 | //I2C1CONCLR_bit.STAC = 1; // Start ruecksetzen
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100 | //I2C1CONCLR_bit.SIC = 1; // Interrupt ruecksetzen
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101 | I2C1CONCLR = 0x20;
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102 | I2C1CONCLR = 0x08;
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103 |
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104 |
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105 | // Auf Interrupt warten (ACK Adresse + Read)
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106 | while (!I2C1CONSET_bit.SI);
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107 | if (I2C1STAT_bit.STATUS != 0x40) return 22;//FALSE;
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108 | //I2C1CONCLR_bit.SIC = 1; // Interrupt ruecksetzen
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109 | //I2C1CONCLR = 0x08;
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110 |
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111 |
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112 | for (i = 0; i < data_cnt; i++)
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113 | {
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114 | // Immer ACK bis auf letztes Byte
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115 | if (i+1 < data_cnt)
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116 | {
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117 | // ACK ausgeben
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118 | I2C1CONSET_bit.AA = 1;
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119 | //I2C1CONCLR_bit.SIC = 1; // Interrupt ruecksetzen
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120 | I2C1CONCLR = 0x08;
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121 |
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122 | // Auf Interrupt warten (RX & ACK fertig)
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123 | while (!I2C1CONSET_bit.SI);
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124 | if (I2C1STAT_bit.STATUS != 0x50) return (33+i);//FALSE;
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125 | }
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126 | else
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127 | {
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128 | // NACK ausgeben
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129 | //I2C1CONCLR_bit.AAC = 1;
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130 | I2C1CONCLR = 0x04;
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131 | //I2C1CONCLR_bit.SIC = 1; // Interrupt ruecksetzen
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132 | I2C1CONCLR = 0x08;
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133 |
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134 | // Auf Interrupt warten (RX & NACK fertig)
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135 | while (!I2C1CONSET_bit.SI);
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136 | if (I2C1STAT_bit.STATUS != 0x58) return (33+i);//FALSE;
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137 | }
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138 |
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139 |
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140 | // Daten einlesen
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141 | data[i] = I2C1DAT;
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142 | }
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143 |
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144 | //I2C1CONCLR_bit.SIC = 1; // Interrupt ruecksetzen
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145 | I2C1CONCLR = 0x08;
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146 |
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147 | // Stop ausgeben
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148 | I2C1CONSET_bit.STO = 1;
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149 |
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150 |
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151 | return TRUE;
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152 | }
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153 | ///////////////////////////////////////////////////////////////////////////
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