root / arduino-1.0 / libraries / Ethernet / examples / BarometricPressureWebServer / BarometricPressureWebServer.ino @ 58d82c77
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1 | 58d82c77 | Tom Mullins | /* |
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2 | SCP1000 Barometric Pressure Sensor Display |
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3 | |||
4 | Serves the output of a Barometric Pressure Sensor as a web page. |
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5 | Uses the SPI library. For details on the sensor, see: |
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6 | http://www.sparkfun.com/commerce/product_info.php?products_id=8161 |
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7 | http://www.vti.fi/en/support/obsolete_products/pressure_sensors/ |
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8 | |||
9 | This sketch adapted from Nathan Seidle's SCP1000 example for PIC: |
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10 | http://www.sparkfun.com/datasheets/Sensors/SCP1000-Testing.zip |
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11 | |||
12 | Circuit: |
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13 | SCP1000 sensor attached to pins 6,7, and 11 - 13: |
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14 | DRDY: pin 6 |
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15 | CSB: pin 7 |
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16 | MOSI: pin 11 |
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17 | MISO: pin 12 |
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18 | SCK: pin 13 |
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19 | |||
20 | created 31 July 2010 |
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21 | by Tom Igoe |
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22 | */ |
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23 | |||
24 | #include <Ethernet.h> |
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25 | // the sensor communicates using SPI, so include the library: |
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26 | #include <SPI.h> |
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27 | |||
28 | |||
29 | // assign a MAC address for the ethernet controller. |
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30 | // fill in your address here: |
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31 | byte mac[] = { |
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32 | 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED}; |
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33 | // assign an IP address for the controller: |
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34 | IPAddress ip(192,168,1,20); |
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35 | IPAddress gateway(192,168,1,1); |
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36 | IPAddress subnet(255, 255, 255, 0); |
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37 | |||
38 | |||
39 | // Initialize the Ethernet server library |
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40 | // with the IP address and port you want to use |
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41 | // (port 80 is default for HTTP): |
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42 | EthernetServer server(80); |
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43 | |||
44 | |||
45 | //Sensor's memory register addresses: |
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46 | const int PRESSURE = 0x1F; //3 most significant bits of pressure |
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47 | const int PRESSURE_LSB = 0x20; //16 least significant bits of pressure |
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48 | const int TEMPERATURE = 0x21; //16 bit temperature reading |
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49 | |||
50 | // pins used for the connection with the sensor |
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51 | // the others you need are controlled by the SPI library): |
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52 | const int dataReadyPin = 6; |
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53 | const int chipSelectPin = 7; |
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54 | |||
55 | float temperature = 0.0; |
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56 | long pressure = 0; |
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57 | long lastReadingTime = 0; |
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58 | |||
59 | void setup() { |
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60 | // start the SPI library: |
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61 | SPI.begin(); |
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62 | |||
63 | // start the Ethernet connection and the server: |
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64 | Ethernet.begin(mac, ip); |
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65 | server.begin(); |
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66 | |||
67 | // initalize the data ready and chip select pins: |
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68 | pinMode(dataReadyPin, INPUT); |
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69 | pinMode(chipSelectPin, OUTPUT); |
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70 | |||
71 | Serial.begin(9600); |
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72 | |||
73 | //Configure SCP1000 for low noise configuration: |
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74 | writeRegister(0x02, 0x2D); |
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75 | writeRegister(0x01, 0x03); |
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76 | writeRegister(0x03, 0x02); |
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77 | |||
78 | // give the sensor and Ethernet shield time to set up: |
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79 | delay(1000); |
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80 | |||
81 | //Set the sensor to high resolution mode tp start readings: |
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82 | writeRegister(0x03, 0x0A); |
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83 | |||
84 | } |
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85 | |||
86 | void loop() { |
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87 | // check for a reading no more than once a second. |
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88 | if (millis() - lastReadingTime > 1000){ |
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89 | // if there's a reading ready, read it: |
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90 | // don't do anything until the data ready pin is high: |
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91 | if (digitalRead(dataReadyPin) == HIGH) { |
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92 | getData(); |
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93 | // timestamp the last time you got a reading: |
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94 | lastReadingTime = millis(); |
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95 | } |
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96 | } |
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97 | |||
98 | // listen for incoming Ethernet connections: |
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99 | listenForEthernetClients(); |
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100 | } |
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101 | |||
102 | |||
103 | void getData() { |
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104 | Serial.println("Getting reading"); |
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105 | //Read the temperature data |
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106 | int tempData = readRegister(0x21, 2); |
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107 | |||
108 | // convert the temperature to celsius and display it: |
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109 | temperature = (float)tempData / 20.0; |
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110 | |||
111 | //Read the pressure data highest 3 bits: |
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112 | byte pressureDataHigh = readRegister(0x1F, 1); |
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113 | pressureDataHigh &= 0b00000111; //you only needs bits 2 to 0 |
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114 | |||
115 | //Read the pressure data lower 16 bits: |
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116 | unsigned int pressureDataLow = readRegister(0x20, 2); |
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117 | //combine the two parts into one 19-bit number: |
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118 | pressure = ((pressureDataHigh << 16) | pressureDataLow)/4; |
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119 | |||
120 | Serial.print("Temperature: "); |
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121 | Serial.print(temperature); |
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122 | Serial.println(" degrees C"); |
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123 | Serial.print("Pressure: " + String(pressure)); |
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124 | Serial.println(" Pa"); |
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125 | } |
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126 | |||
127 | void listenForEthernetClients() { |
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128 | // listen for incoming clients |
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129 | EthernetClient client = server.available(); |
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130 | if (client) { |
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131 | Serial.println("Got a client"); |
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132 | // an http request ends with a blank line |
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133 | boolean currentLineIsBlank = true; |
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134 | while (client.connected()) { |
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135 | if (client.available()) { |
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136 | char c = client.read(); |
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137 | // if you've gotten to the end of the line (received a newline |
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138 | // character) and the line is blank, the http request has ended, |
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139 | // so you can send a reply |
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140 | if (c == '\n' && currentLineIsBlank) { |
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141 | // send a standard http response header |
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142 | client.println("HTTP/1.1 200 OK"); |
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143 | client.println("Content-Type: text/html"); |
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144 | client.println(); |
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145 | // print the current readings, in HTML format: |
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146 | client.print("Temperature: "); |
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147 | client.print(temperature); |
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148 | client.print(" degrees C"); |
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149 | client.println("<br />"); |
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150 | client.print("Pressure: " + String(pressure)); |
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151 | client.print(" Pa"); |
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152 | client.println("<br />"); |
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153 | break; |
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154 | } |
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155 | if (c == '\n') { |
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156 | // you're starting a new line |
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157 | currentLineIsBlank = true; |
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158 | } |
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159 | else if (c != '\r') { |
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160 | // you've gotten a character on the current line |
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161 | currentLineIsBlank = false; |
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162 | } |
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163 | } |
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164 | } |
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165 | // give the web browser time to receive the data |
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166 | delay(1); |
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167 | // close the connection: |
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168 | client.stop(); |
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169 | } |
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170 | } |
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171 | |||
172 | |||
173 | //Send a write command to SCP1000 |
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174 | void writeRegister(byte registerName, byte registerValue) { |
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175 | // SCP1000 expects the register name in the upper 6 bits |
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176 | // of the byte: |
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177 | registerName <<= 2; |
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178 | // command (read or write) goes in the lower two bits: |
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179 | registerName |= 0b00000010; //Write command |
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180 | |||
181 | // take the chip select low to select the device: |
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182 | digitalWrite(chipSelectPin, LOW); |
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183 | |||
184 | SPI.transfer(registerName); //Send register location |
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185 | SPI.transfer(registerValue); //Send value to record into register |
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186 | |||
187 | // take the chip select high to de-select: |
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188 | digitalWrite(chipSelectPin, HIGH); |
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189 | } |
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190 | |||
191 | |||
192 | //Read register from the SCP1000: |
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193 | unsigned int readRegister(byte registerName, int numBytes) { |
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194 | byte inByte = 0; // incoming from the SPI read |
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195 | unsigned int result = 0; // result to return |
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196 | |||
197 | // SCP1000 expects the register name in the upper 6 bits |
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198 | // of the byte: |
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199 | registerName <<= 2; |
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200 | // command (read or write) goes in the lower two bits: |
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201 | registerName &= 0b11111100; //Read command |
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202 | |||
203 | // take the chip select low to select the device: |
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204 | digitalWrite(chipSelectPin, LOW); |
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205 | // send the device the register you want to read: |
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206 | int command = SPI.transfer(registerName); |
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207 | // send a value of 0 to read the first byte returned: |
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208 | inByte = SPI.transfer(0x00); |
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209 | |||
210 | result = inByte; |
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211 | // if there's more than one byte returned, |
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212 | // shift the first byte then get the second byte: |
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213 | if (numBytes > 1){ |
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214 | result = inByte << 8; |
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215 | inByte = SPI.transfer(0x00); |
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216 | result = result |inByte; |
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217 | } |
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218 | // take the chip select high to de-select: |
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219 | digitalWrite(chipSelectPin, HIGH); |
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220 | // return the result: |
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221 | return(result); |
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222 | } |