Revision 0:7c1c768af92a, committed 2019-05-09

Comitter:

star297

Date:

Thu May 09 22:17:49 2019 +0000

Child:

1:5ab1e58f1574

Child:

2:74731b8476a0

Commit message:

Initial revision

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/max6675.cpp	Thu May 09 22:17:49 2019 +0000
@@ -0,0 +1,30 @@
+
+#include "max6675.h"
+
+max6675::max6675(PinName miso, PinName sclk, PinName cs) :
+    max(NC, miso, sclk), _cs(cs)
+{
+    max.format(16,1);   // set 16 bit SPI format
+    max.frequency(4000000);
+}
+float max6675::gettemp(int cf)
+{
+    float temp  = 0;
+    int tempByte= 0;
+    
+    _cs = 0;
+    wait_us(1);     // wait to stablize
+    tempByte  =  max.write(0);
+    wait_us(1);     // wait to finish
+    _cs = 1;
+
+    if (tempByte & (1<<2)) { // faulty or no sensor connected
+        return -99;
+    } else {
+        temp = (tempByte)/32.0f;
+    }
+    if(cf) {
+        temp = (temp*9.0f/5.0f) + 32.0f; // Convert value to ˚F
+    }
+    return temp;
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/max6675.h	Thu May 09 22:17:49 2019 +0000
@@ -0,0 +1,48 @@
+#ifndef max6675_h
+#define max6675_h
+
+#include "mbed.h"
+
+/*
+#include "mbed.h"
+#include "max6675.h"
+
+max6675 sensor(D5,D3,D6);  //miso, sclk, cs
+Serial pc(USBTX,USBRX);
+
+int main()
+{
+    pc.baud(921600);
+    pc.printf("\033[0m\033[2J\033[HMAX6675 Thermocouple!\r\n\n\n");
+
+    int cf = 0; // 0 Centigrade, 1 Fahrenheit
+
+    while (1) {
+
+        float temp = sensor.gettemp(cf);
+        if (cf) {
+            printf(" Temp: %4.2f%cF \n\033[2K\033[1A",temp,176);
+        } else {
+            printf(" Temp: %4.2f%cC \n\033[2K\033[1A",temp,176);
+        }
+        wait_ms(250);   // requires 250mS for temperature conversion process
+    }
+}
+*/
+
+
+class max6675
+{    
+  public:
+  
+    max6675(PinName miso, PinName sclk, PinName cs);
+    
+    // read temperature 0 Centigrade, 1 Fahrenheit       
+    float gettemp(int cf);    
+    
+  private:  
+    SPI max;
+    DigitalOut _cs;    
+};
+
+#endif