Diff: measurement/Potentiometer.cpp

Revision:

101:dbcd3bc51758

Child:

113:3872569be2af

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/measurement/Potentiometer.cpp	Fri May 08 12:19:57 2015 +0000
@@ -0,0 +1,37 @@
+#include <stdio.h>
+#include "Potentiometer.h"
+#include "SmartRestConf.h"
+#include "logging.h"
+
+// Cutoff for avoiding sending similar sensor data.
+#define THRESHOLD_PERCENT_ANA 0.02
+// Timeout for forcing a sending even if  readings are similar [seconds]
+#define TIME_LIMIT_ANA 900
+
+AnalogIn analog1(A0);
+AnalogIn analog2(A1);
+
+size_t Potentiometer::read(char *buf, size_t maxLen, char *status, size_t num)
+{
+        static const char *fmt = "107,%ld,%f,%f\r\n";
+        float data[2] = {(float)analog1*100, (float)analog2*100};
+
+        if (abs(oldValues[0]-data[0]) <= abs(oldValues[0])*THRESHOLD_PERCENT_ANA &&
+            abs(oldValues[1]-data[1]) <= abs(oldValues[1])*THRESHOLD_PERCENT_ANA) {
+                time_t t_interval = time(NULL) - t_start;
+                if (t_interval < TIME_LIMIT_ANA) {
+                        return 0;
+                } else {
+                        aDebug("Poti: Timeout at %d s.\n", t_interval);
+                }
+        }
+
+        size_t l = snprintf(buf, maxLen, fmt, deviceID, data[0], data[1]);
+        if (status) {
+                snprintf(status, num, "Send Poti %.1f,%.1f", data[0], data[1]);
+        }
+        oldValues[0] = data[0];
+        oldValues[1] = data[1];
+        t_start = time(NULL);
+        return l;
+}
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