Diff: libraries/Thermocouple/Thermocouple_core_cpp.txt

Revision:

33:c3ec596a29c2

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libraries/Thermocouple/Thermocouple_core_cpp.txt	Mon Nov 07 16:27:12 2016 +0200
@@ -0,0 +1,43 @@
+#include "thermocouple.h"
+
+// http://srdata.nist.gov/its90/download/allcoeff.tab
+
+Thermocouple::Thermocouple(){}
+Thermocouple::~Thermocouple() {}
+
+float Thermocouple::lookup(const int32_t *lut, float voltage, uint16_t size, int16_t offset) {
+    uint16_t first = 0;
+    uint16_t last = size - 1;
+    uint16_t middle = (first + last) / 2;
+    int32_t integer_voltage = int32_t(voltage*1000);
+    while (first <= last) {
+        if (lut[middle] < integer_voltage)
+            first = middle + 1;
+        else if (lut[middle] == integer_voltage) {
+            return static_cast<float>(middle + offset);
+        } else
+            last = middle - 1;
+
+        middle = (first + last) / 2;
+    }
+    if (first > last)
+        return static_cast<float>(first+offset);
+
+    return 0; // should never get here
+}
+
+float Thermocouple::convert(float voltage, const thermocouple_poly_subrange range[], const int n) {
+    int range_id = 0;
+    float temperature=0;
+    for(range_id = 0 ; range_id<n;range_id++)
+    {
+        if(voltage > range[range_id].min_voltage_range && voltage <= range[range_id].max_voltage_range)
+            break;
+    }
+
+    for (int i = 0; i < range[range_id].n; i++) {
+        temperature += (range[range_id].coef[i] * pow(10,range[range_id].power[i])) * pow(voltage, i);
+    }
+    return temperature;
+}
+