grove: add grove temperature sensor support and example

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

examples/CMakeLists.txt

@@ -1,8 +1,10 @@
 add_executable (compass compass.cxx)
 add_executable (groveled groveled.cxx)
+add_executable (grovetemp grovetemp.cxx)
 
 include_directories (${PROJECT_SOURCE_DIR}/src/hmc5883l)
 include_directories (${PROJECT_SOURCE_DIR}/src/grove)
 
 target_link_libraries (compass hmc5883l)
 target_link_libraries (groveled grove)
+target_link_libraries (grovetemp grove)

examples/grovetemp.cxx

@@ -0,0 +1,41 @@
+/*
+ * Author: Brendan Le Foll <brendan.le.foll@intel.com>
+ * Copyright (c) 2014 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <unistd.h>
+#include <iostream>
+#include "grove.h"
+
+int
+main(int argc, char **argv)
+{
+    // Use i2c device 0 all the time
+    upm::GroveTemp* s = new upm::GroveTemp(0);
+    std::cout << s->name() << std::endl;
+    for (int i=0; i < 10; i++) {
+        std::cout << s->value() << std::endl;
+        sleep(1);
+    }
+
+    return 0;
+}

src/grove/grove.cxx

@@ -22,10 +22,15 @@
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
+#include <iostream>
+
 #include "grove.h"
+#include "math.h"
 
 using namespace upm;
 
+//// GroveLed ////
+
 GroveLed::GroveLed(int pin)
 {
     maa_init();
@@ -56,3 +61,30 @@ maa_result_t GroveLed::off()
 {
     return write(0);
 }
+
+//// GroveTemp ////
+
+GroveTemp::GroveTemp(unsigned int pin)
+{
+    maa_init();
+    m_aio = maa_aio_init(pin);
+    m_name = "Temperature Sensor";
+}
+
+GroveTemp::~GroveTemp()
+{
+    maa_aio_close(m_aio);
+}
+
+int GroveTemp::value ()
+{
+    int a = maa_aio_read_u16(m_aio);
+    float r = (float)(1023-a)*10000/a;
+    float t = 1/(logf(r/10000)/3975 + 1/298.15)-273.15;
+    return (int) t;
+}
+
+float GroveTemp::raw_value()
+{
+    return (float) maa_aio_read_u16(m_aio);
+}

src/grove/grove.h

@@ -24,6 +24,7 @@
 #pragma once
 
 #include <string>
+#include <maa/aio.h>
 #include <maa/gpio.h>
 
 namespace upm {
@@ -47,7 +48,17 @@ class GroveLed: public Grove {
         maa_result_t off();
         maa_result_t on();
     private:
-        maa_gpio_context * m_gpio;
+        maa_gpio_context* m_gpio;
+};
+
+class GroveTemp: public Grove {
+    public:
+        GroveTemp(unsigned int pin);
+        ~GroveTemp();
+        float raw_value();
+        int value();
+    private:
+        maa_aio_context* m_aio;
 };
 
 }