hka5: Initial implementation

This module implements support for the DFRobot Laser PM2.5 Sensor.  It
connects to a UART at 9600 baud.  This is the only baud rate
supported.  It optionally supports Reset and Set/Sleep gpios as well.

Signed-off-by: Jon Trulson <jtrulson@ics.com>

examples/c/CMakeLists.txt

@@ -92,6 +92,7 @@ add_example (mma7361)
 add_example (bh1750)
 add_example (urm37)
 add_example (urm37-uart)
+add_example (hka5)
 
 # Custom examples
 add_custom_example (nmea_gps_i2c-example-c nmea_gps_i2c.c nmea_gps)

examples/c/hka5.c

@@ -0,0 +1,78 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 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 <signal.h>
+
+#include "hka5.h"
+
+bool shouldRun = true;
+
+void sig_handler(int signo)
+{
+  if (signo == SIGINT)
+    shouldRun = false;
+}
+
+int main()
+{
+  signal(SIGINT, sig_handler);
+
+//! [Interesting]
+
+  // Instantiate a HKA5 sensor on uart 0.  We don't use the set or
+  // reset pins, so we pass -1 for them.
+  hka5_context sensor = hka5_init(0, -1, -1);
+
+  if (!sensor)
+    {
+      printf("hka5_init() failed.\n");
+      return 1;
+    }
+
+  // update once every 2 seconds and output data
+  while (shouldRun)
+    {
+      if (hka5_update(sensor) != UPM_SUCCESS)
+        {
+          printf("hka5_update() failed, exiting.\n");
+          shouldRun = false;
+        }
+
+      printf("PM 1  : %d ug/m3\n", hka5_get_pm1(sensor));
+      printf("PM 2.5: %d ug/m3\n", hka5_get_pm2_5(sensor));
+      printf("PM 10 : %d ug/m3\n", hka5_get_pm10(sensor));
+      printf("\n");
+
+      sleep(2);
+    }
+
+//! [Interesting]
+
+  printf("Exiting\n");
+
+  hka5_close(sensor);
+
+  return 0;
+}