Diff: ADT7320_SPI.cpp

Revision:

0:66156a1e785a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ADT7320_SPI.cpp	Sat Dec 24 15:31:40 2016 +0000
@@ -0,0 +1,52 @@
+#include "ADT7320_SPI.h"
+
+//#include "mbed.h"
+
+ADT7320_SPI::ADT7320_SPI(PinName mosi, PinName miso, PinName sclk, PinName cs) : spi_(mosi, miso, sclk),cs_(cs) {
+    // Chip must be deselected
+    cs_ = 1;
+    // Setup the spi for 8 bit data, high steady state clock,
+    // second edge capture, with a 1MHz clock rate
+    spi_.format(8,3);
+    spi_.frequency(1000000);
+}
+
+//Read from register from the ADT7320:
+unsigned int ADT7320_SPI::readRegister(uint8_t thisRegister, int bytesToRead ) {
+  uint8_t inByte = 0;          // incoming byte from the SPI
+  unsigned int result = 0;  // result to return
+  // take the chip select low to select the device:
+  cs_=0;
+  // send the device the register you want to read:
+  spi_.write(thisRegister);
+  // send a value of 0 to read the first byte returned:
+  result = spi_.write(0xFF);
+  // decrement the number of bytes left to read:
+  bytesToRead--;
+  // if you still have another byte to read:
+  if (bytesToRead > 0) {
+    // shift the first byte left, then get the second byte:
+    result = result << 8;
+    inByte = spi_.write(0xFF);
+    // combine the byte you just got with the previous one:
+    result = result | inByte;
+    // decrement the number of bytes left to read:
+    bytesToRead--;
+  }
+  // take the chip select high to de-select:
+  cs_=1;
+  // return the result:
+  return(result);
+}
+
+float ADT7320_SPI::readTemp(void)
+{
+    //Read the temperature data
+    unsigned int tempData = readRegister(0x50, 2); // 0x50 is read commad for 0x02 register
+    tempData = tempData/8;// MSB bit15 and LSB bit4 so received value need to be divide/8
+
+    // convert the temperature to celsius and display it:
+    float realTemp = (float)tempData * 0.0625;
+    return realTemp;  
+}
+     
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