hmc5883l: C port; FTI; C++ wraps C

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

examples/c/CMakeLists.txt

@@ -145,6 +145,7 @@ add_example (mcp2515)
 add_example (max30100)
 add_example (speaker)
 add_example (cjq4435)
+add_example (hmc5883l)
 
 # Custom examples
 add_custom_example (nmea_gps_i2c-example-c nmea_gps_i2c.c nmea_gps)

examples/c/hmc5883l.c

@@ -0,0 +1,82 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2017 Intel Corporation.
+ *
+ * Ported based on original C++ code by:
+ * Author: Brendan Le Foll <brendan.le.foll@intel.com>
+ * Contributions: Mihai Tudor Panu <mihai.tudor.panu@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 <stdio.h>
+#include <signal.h>
+
+#include <upm_utilities.h>
+
+#include "hmc5883l.h"
+
+bool shouldRun = true;
+
+void sig_handler(int signo)
+{
+  if (signo == SIGINT)
+    shouldRun = false;
+}
+
+int main(int argc, char **argv)
+{
+    signal(SIGINT, sig_handler);
+
+//! [Interesting]
+    // Instantiate an HMC8883L on I2C bus 0
+    hmc5883l_context sensor = hmc5883l_init(0);
+
+    if (!sensor)
+    {
+        printf("%s: hmc5883l_init() failed\n", __FUNCTION__);
+        return 1;
+    }
+
+    hmc5883l_set_declination(sensor, 0.2749); // Set your declination
+                                              // from true north in
+                                              // radians
+
+    // Print out the coordinates, heading, and direction every second
+    while (shouldRun)
+    {
+        hmc5883l_update(sensor); // Update the coordinates
+        const int16_t *pos = hmc5883l_coordinates(sensor);
+
+        printf("coor: %5d %5d %5d ", pos[0], pos[1], pos[2]);
+        printf("heading: %5.2f direction: %3.2f\n",
+               hmc5883l_heading(sensor), hmc5883l_direction(sensor));
+
+        upm_delay(1);
+    }
+
+    hmc5883l_close(sensor);
+
+//! [Interesting]
+
+    return 0;
+}