1 | //******************************************************************************
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2 | //* wait (Warteschleife, Zyklen)
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3 | //******************************************************************************
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4 | void wait(unsigned int i)
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5 | {
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6 | unsigned int j;
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7 | for (j = 0; j < i; j++);
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8 | }
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9 |
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10 | //******************************************************************************
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11 | //* SerialSendLsbFirst (Sendet Daten zum MS5534A)
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12 | //******************************************************************************
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13 | void SerialSendLsbFirst(int pattern, int nbr_clock)
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14 | {
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15 | int i;
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16 | P2OUT &= ~SCK;
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17 | wait(10);
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18 |
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19 | for (i = 0; i < nbr_clock; i++) {
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20 | if (pattern & 0x01)
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21 | P2OUT |= SDO;
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22 | else
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23 | P2OUT &= ~SDO;
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24 | wait(10);
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25 | P2OUT |= SCK;
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26 | wait(10);
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27 | P2OUT &= ~SCK;
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28 | pattern = pattern >> 1;
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29 | }
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30 | }
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31 |
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32 | //******************************************************************************
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33 | //* reset_MS5534A (Sendet Resetsignal zum MS5534A)
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34 | //******************************************************************************
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35 | void reset_MS5534A(void)
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36 | {
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37 | SerialSendLsbFirst(0x55, 8); // 21-bit reset sequence 0x55 0x55 0x00
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38 | SerialSendLsbFirst(0x55, 8);
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39 | SerialSendLsbFirst(0x00, 5);
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40 | }
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41 |
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42 | //******************************************************************************
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43 | //* SerialGet16 (MS5534A auslesen)
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44 | //******************************************************************************
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45 | long SerialGet16(void)
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46 | {
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47 | int j;
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48 | long v;
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49 | v = 0;
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50 | P2OUT &= ~SCK;
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51 | wait(20);
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52 |
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53 | for (j = 0; j < 16; j++) {
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54 | P2OUT |= SCK;
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55 | wait(20);
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56 | P2OUT &= ~SCK;
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57 | v = v << 1;
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58 | if (P2IN & SDI)
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59 | v = v | 1;
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60 | wait(20);
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61 | }
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62 |
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63 | return (v);
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64 | }
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65 |
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66 | //******************************************************************************
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67 | //* getW (MS5534A CalibrationWords auslesen)
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68 | //******************************************************************************
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69 | long getW(int index)
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70 | {
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71 | int cmd1 = 0, cmd2 = 0;
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72 | long wdata;
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73 | wdata = 0;
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74 |
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75 | switch (index) {
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76 | case 0:
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77 | cmd1 = 0x57;
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78 | cmd2 = 0x01;
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79 | break;
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80 | case 1:
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81 | cmd1 = 0xD7;
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82 | break;
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83 | case 2:
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84 | cmd1 = 0x37;
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85 | cmd2 = 0x01;
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86 | break;
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87 | case 3:
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88 | cmd1 = 0xB7;
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89 | break;
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90 | }
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91 | SerialSendLsbFirst(cmd1, 8);
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92 | SerialSendLsbFirst(cmd2, 5);
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93 | wdata = SerialGet16();
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94 | SerialSendLsbFirst(0x00, 1);
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95 |
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96 | return (wdata);
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97 | }
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98 |
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99 | //******************************************************************************
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100 | //* WaitOnDoutFall (auf MS5534A ADC warten)
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101 | //******************************************************************************
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102 | long waitOnDoutFall(void)
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103 | {
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104 | int cnt = 0;
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105 | short working = 1;
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106 | long error = 0;
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107 |
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108 | while (working) {
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109 | working = (P2IN & SDI);
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110 | cnt++;
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111 | wait(10);
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112 | if (cnt >= 50) {
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113 | working = 0;
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114 | error = 1;
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115 | }
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116 | }
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117 |
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118 | return (error);
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119 | }
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120 |
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121 | //******************************************************************************
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122 | //* getData (Druck und Temperatur auslesen (MS5534A))
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123 | //******************************************************************************
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124 | long get_data(int reg_sel)
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125 | {
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126 | long d1;
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127 | int error, pulse = 2;
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128 |
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129 | if (reg_sel == PRESSURE) {
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130 | SerialSendLsbFirst(0x2F, 8);
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131 | SerialSendLsbFirst(0x00, 2);
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132 | } else {
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133 | SerialSendLsbFirst(0x4F, 8);
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134 | SerialSendLsbFirst(0x00, 3);
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135 | pulse = 1;
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136 | }
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137 |
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138 | error = 0;
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139 | if (!(P2IN & SDI))
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140 | error = 1;
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141 |
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142 | SerialSendLsbFirst(0x00, pulse);
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143 |
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144 | if (!error)
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145 | error = waitOnDoutFall();
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146 |
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147 | if (!error)
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148 | d1 = SerialGet16();
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149 | else
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150 | d1 = 0;
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151 |
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152 | if (reg_sel == PRESSURE)
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153 | SerialSendLsbFirst(0x00, 1);
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154 |
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155 | //if (error_pt != 0)
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156 | // *error_pt = error;
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157 |
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158 | return (d1);
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159 | }
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160 |
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161 | //******************************************************************************
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162 | //* ConvertWtoC (4 Words => 6 CalibrationParams)
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163 | //******************************************************************************
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164 | long ConvertWtoC5534(int ix, long W1, long W2, long W3, long W4)
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165 | {
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166 | long c = 0;
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167 | long x, y;
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168 |
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169 | switch (ix) {
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170 | case 0:
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171 | c = (W1 >> 1) & 0x7FFF;
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172 | break;
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173 | case 1:
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174 | x = (W3 << 6) & 0x0FC0;
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175 | y = W4 & 0x003F;
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176 | c = x | y;
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177 | break;
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178 | case 2:
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179 | c = (W4 >> 6) & 0x03FF;
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180 | break;
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181 | case 3:
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182 | c = (W3 >> 6) & 0x03FF;
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183 | break;
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184 | case 4:
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185 | x = (W1 << 10) & 0x0400;
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186 | y = (W2 >> 6) & 0x03FF;
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187 | c = x | y;
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188 | break;
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189 | case 5:
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190 | c = W2 & 0x003F;
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191 | break;
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192 | }
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193 |
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194 | return (c);
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195 | }
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196 |
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197 | //******************************************************************************
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198 | //* read_absdruck (Liest Sensor aus)
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199 | //******************************************************************************
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200 | void read_absdruck()
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201 | {
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202 | int i;
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203 |
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204 | reset_MS5534A(); // Initialize MS5534A
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205 |
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206 | for (i = 0; i < 4; i++) // Get MS5534 calibration words
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207 | cw[i] = getW(i);
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208 |
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209 |
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210 | for (i = 0; i < 6; i++) // Extract cal coefficients
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211 | {
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212 | fc[i] = ConvertWtoC5534(i, cw[0], cw[1], cw[2], cw[3]);
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213 | // printf("%lu ", fc[i]);
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214 | }
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215 |
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216 | if ((cw[0] != 0) & (cw[0] != 0xFFFF)) // Check for valid sensor
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217 | { // otherwise return error defaults
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218 | d1 = get_data(PRESSURE); // read pressure value
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219 | d2 = get_data(TEMPERATURE); // read temperature value
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220 | }
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221 |
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222 | }
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