Diff: HygroClip2.cpp

Revision:

0:0f5101a649db

Child:

1:810b9b0dd9a4

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/HygroClip2.cpp	Tue Feb 16 11:34:37 2016 +0000
@@ -0,0 +1,69 @@
+#include "HygroClip2.h"
+
+HygroClip2::HygroClip2(PinName tx, PinName rx)
+    : uart_(tx, rx), temperature_(0.0f), humidity_(0.0f), dataReadyToPars_(false)
+{
+    buffer_[HYGROCLIP_BUFFER_SIZE] = 0;
+    uart_.baud(19200);
+    uart_.attach(this, &HygroClip2::uartCallback);
+}
+
+void HygroClip2::uartCallback()
+{
+    static size_t index = 0;
+    uint8_t data = uart_.getc();
+    
+    if (dataReadyToPars_) {
+        return;
+    }
+
+    if (data == '{') {
+        index = 0;
+    } else if (data == '\r') {
+        dataReadyToPars_ = true;
+    } else {
+        buffer_[index] = data;
+        index++;
+    }
+
+    if (index >= HYGROCLIP_BUFFER_SIZE) {
+        index = 0;
+    }
+}
+
+void HygroClip2::update()
+{
+    if (dataReadyToPars_)
+    {
+        dataReadyToPars_ = false;
+        humidity_ = atof(reinterpret_cast<char *>(&buffer_[11]));
+        temperature_ = atof(reinterpret_cast<char *>(&buffer_[29]));
+    }
+    else
+    {
+        humidity_ = -1.0f;
+        temperature_ = -1.0f;
+    }
+    
+    uart_.printf("{F00RDD}\r");
+}
+
+float HygroClip2::getHumidity()
+{
+    return humidity_;
+}
+float HygroClip2::getTemperature()
+{
+    return temperature_;
+}
+float HygroClip2::getDewPoint()
+{
+    return 243.04f*(log(getHumidity()/100)+((17.625*getTemperature())/(243.04+getTemperature())))/(17.625-log(getHumidity()/100)-((17.625*getTemperature())/(243.04+getTemperature())));
+}
+float HygroClip2::getAbsolutHumidity()
+{
+    float saturationPressure = 611.2f * exp((17.62f * getTemperature()) / (243.12f + getTemperature()));
+    float partialPressure = (getHumidity() * saturationPressure) / 100.0f;
+    float absoluteHumidity = partialPressure / (461.51f * (getTemperature() + 273.15f));
+    return absoluteHumidity*1000;
+}