max30100: Initial commit - MAX30100 pulse oximeter

* c/c++ source
    * java/js/python/c/c++ examples
    * Doc image (png)
    * Tested on Intel Edison
    * TODO: Tuning for SpO2 reading

Signed-off-by: Noel Eck <noel.eck@intel.com>

examples/c/CMakeLists.txt

@@ -142,6 +142,7 @@ add_example (ims)
 add_example (ecezo)
 add_example (mb704x)
 add_example (mcp2515)
+add_example (max30100)
 
 # Custom examples
 add_custom_example (nmea_gps_i2c-example-c nmea_gps_i2c.c nmea_gps)

examples/c/max30100.c

@@ -0,0 +1,130 @@
+/*
+ * Author: Noel Eck <noel.eck@intel.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 <stdio.h>
+#include <signal.h>
+
+#include "max30100.h"
+#include "upm_utilities.h"
+
+bool shouldRun = true;
+
+void sig_handler(int signo)
+{
+    if (signo == SIGINT)
+        shouldRun = false;
+}
+
+void my_sample_handler(max30100_value sample, void* arg)
+{
+    printf("My callback sample IR: %d R: %d\n",
+            sample.IR, sample.R);
+}
+
+int main()
+{
+    signal(SIGINT, sig_handler);
+
+    //! [Interesting]
+    max30100_context* sensor = max30100_init(0);
+
+    if (!sensor)
+    {
+        printf("max30100_init() failed\n");
+        return -1;
+    }
+
+    /* Get the temperature */
+    float temp;
+    if (max30100_get_temperature(sensor, &temp) != UPM_SUCCESS)
+    {
+        printf("max30100_get_temperature failed\n");
+        goto max30100_exit;
+    }
+
+    /* Get the version */
+    uint16_t version;
+    if (max30100_get_version(sensor, &version) != UPM_SUCCESS)
+    {
+        printf("max30100_get_version failed\n");
+        goto max30100_exit;
+    }
+
+    printf("Temperature: %f C\n", temp);
+    printf("Version: 0x%04x\n", version);
+
+    /* Set high-res (50 Hz, 16-bit) */
+    if (max30100_set_high_res(sensor, true) != UPM_SUCCESS)
+    {
+        printf("max30100_set_high_res failed\n");
+        goto max30100_exit;
+    }
+
+    /* Set to sample SpO2 */
+    if (max30100_set_mode(sensor, MAX30100_MODE_SPO2_EN) != UPM_SUCCESS)
+    {
+        printf("max30100_set_mode failed\n");
+        goto max30100_exit;
+    }
+
+    /* Read continuously, stepping up the LED current every second,
+     * us GPIO 0 as the interrupt pin */
+    max30100_sample_continuous(sensor, 0, false, &my_sample_handler, sensor);
+    for (int i = MAX30100_LED_CURRENT_0_0_MA;
+         i <= MAX30100_LED_CURRENT_50_0_MA && shouldRun; i++)
+    {
+        /* Toggle the LED current */
+        printf("Setting LED current = %d\n", i);
+
+        if ( max30100_set_current(sensor, (MAX30100_LED_CURRENT)i,
+                    (MAX30100_LED_CURRENT)i) != UPM_SUCCESS )
+        {
+            printf("max30100_set_current failed\n");
+            goto max30100_exit;
+        }
+
+        upm_delay(1);
+    }
+
+    /* Read individual samples */
+    for (int i = 0; i < 10; i++)
+    {
+        max30100_value samp;
+        if (max30100_sample(sensor, &samp) != UPM_SUCCESS)
+        {
+            printf("max30100_sample failed\n");
+            goto max30100_exit;
+        }
+
+        printf("Single value IR: %d R: %d\n", samp.IR, samp.R);
+    }
+
+max30100_exit:
+    //! [Interesting]
+    printf("Exiting\n");
+    max30100_close(sensor);
+
+    return 0;
+}