Milosch Meriac
Median filtered & triggered + buffered RGB readings
Dependencies: mbed rgb_sensor_buffer
Revision 0:c41a5885f681, committed 2014-07-03
- Comitter:
- meriac
- Date:
- Thu Jul 03 16:54:13 2014 +0000
- Child:
- 1:6a17b13e3ef4
- Commit message:
- Example for RGB sensor code
Changed in this revision
--- /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
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Thu Jul 03 16:54:13 2014 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/04dd9b1680ae \ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/rgb_sensor_buffer.lib Thu Jul 03 16:54:13 2014 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/meriac/code/rgb_sensor_buffer/#bbd86bfe6577