Diff: max6675.cpp

Revision:

0:b49d36e03092

Child:

2:661ac326e3b3

diff -r 000000000000 -r b49d36e03092 max6675.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/max6675.cpp	Sat May 15 06:26:05 2010 +0000
@@ -0,0 +1,42 @@
+
+#include <mbed.h>
+#include "max6675.h"
+
+max6675::max6675(SPI& _spi, PinName _ncs) : spi(_spi), ncs(_ncs) {
+
+}
+
+float max6675::read_temp() {
+    short value = 0;
+    float temp = 0;
+    
+    uint8_t highByte=0;
+    uint8_t lowByte=0;
+    
+    select();
+    wait(.25); //This delay is needed else it does'nt seem to update the temp
+
+    highByte = spi.write(0);
+    lowByte = spi.write(0);
+    deselect();
+
+
+    if (lowByte & (1<<2)) {
+        printf("No Probe");
+    } else {
+        value = (highByte << 5 | lowByte>>3);
+    }
+
+    temp = (value*0.25); // Multiply the value by 0.25 to get temp in ˚C or
+                         //  * (9.0/5.0)) + 32.0;   // Convert value to ˚F (ensure proper floats!)
+
+return temp;
+}
+
+void max6675::select() {
+    ncs = 0;
+}
+
+void max6675::deselect() {
+    ncs = 1;
+}