Diff: main.cpp

Revision:

0:c41a5885f681

Child:

2:f72e7a4d7395

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Jul 03 16:54:13 2014 +0000
@@ -0,0 +1,130 @@
+/* Discrete RGB color sensor
+ *
+ * - uses single-channel light-dependent resistor (via ADC)
+ *   and a RGB LED.
+ * -  compensates background light
+ *
+ * Copyright (c) 2014 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <mbed.h>
+#include "rgb_sensor_buffer.h"
+
+#define RGB_TRESHOLD 200
+#define COUNT(x) (sizeof(x)/sizeof(x[0]))
+#define RGB_VALUES 512
+
+/* serial console */
+static TRGB g_buffer[RGB_VALUES];
+static int g_median[RGB_VALUES];
+static Serial console(USBTX, USBRX);
+
+#ifdef DEBUG
+static void rgb_print(const TRGB &color)
+{
+    int i;
+
+    console.printf("\t[");
+    for(i=0; i<COUNT(color.data); i++)
+        console.printf("%s%4i", i?",":"", color.data[i] / RGB_OVERSAMPLING);
+    console.printf("]");
+}
+#endif/*DEBUG*/
+
+static int median_compare(const void* a, const void *b)
+{
+        return *((int*)a) - *((int*)b);
+}
+
+static bool median(TRGB &color, int count)
+{
+    int channel, i;
+
+    if(count<=0)
+        return false;
+
+    /* sort all three RGB channels to get median */
+    for(channel=0; channel<3; channel++)
+    {
+        for(i=0; i<count; i++)
+            g_median[i] = g_buffer[i].data[channel];
+
+        qsort(&g_median, count, sizeof(g_median[0]), &median_compare);
+
+        color.data[channel] = g_median[count/2];
+    }
+
+    return true;
+}
+
+
+int main() {
+    int res, i;
+    TRGB color;
+
+    console.baud(115200);
+
+    /* R,G,B pins and ADC for light dependent resistor */
+    RGB_SensorBuffer rgb(p23,p24,p25,p20);
+
+    /* needed for time measurement */
+    Timer timer;
+
+    while(1) {
+
+        /* start four channel RGB conversion */
+        timer.reset();
+        timer.start();
+
+        res = rgb.trigger(g_buffer, COUNT(g_buffer), RGB_TRESHOLD);       
+
+        /* stop time measurement */
+        timer.stop();
+    
+        if(res<=0)
+        {
+            console.printf("// failed to capture RGB values (%i)\r\n", res);
+            while(1);
+        }
+
+        /* calculate RGB median */
+        median(color, res);
+        /* print normalized median */
+        i = (color.ch.red + color.ch.green + color.ch.blue);
+        console.printf("\t[%4i,%4i,%4i,%5i], // %i values in %ims (%i/s)\n\r",
+            (color.ch.red   * 0xFFF)/i,
+            (color.ch.green * 0xFFF)/i,
+            (color.ch.blue  * 0xFFF)/i,
+            i/RGB_OVERSAMPLING,
+            res,
+            timer.read_ms(),
+            (res*1000UL)/timer.read_ms()
+        );
+
+#ifdef DEBUG
+        console.printf("\r\nvar test = [\r\n",
+            res,
+            timer.read_ms(),
+            (res*1000UL)/timer.read_ms());
+
+        for(i=0; i<res; i++)
+        {
+            rgb_print(g_buffer[i]);
+            console.printf(i<(res-1) ? ",\r\n":"];\r\n\r\n");
+        }
+#endif/*DEBUG*/
+
+    }
+}
\ No newline at end of file