Milosch Meriac / Mbed 2 deprecated rgb_sensor_buffer_example

Median filtered & triggered + buffered RGB readings

Dependencies:   mbed rgb_sensor_buffer

main.cpp@7:bc856471c871, 2014-07-08 (annotated)

Committer:
meriac
Date:
Tue Jul 08 16:07:50 2014 +0000
Revision:
7:bc856471c871
Parent:
6:3f5ea82fdf62 
Reduce detection treshold to increase detection likelihood

Who changed what in which revision?

UserRevisionLine numberNew contents of line
meriac 0:c41a5885f681 1 /* Discrete RGB color sensor
meriac 0:c41a5885f681 2 *
meriac 0:c41a5885f681 3 * - uses single-channel light-dependent resistor (via ADC)
meriac 0:c41a5885f681 4 * and a RGB LED.
meriac 0:c41a5885f681 5 * - compensates background light
meriac 0:c41a5885f681 6 *
meriac 0:c41a5885f681 7 * Copyright (c) 2014 ARM Limited
meriac 0:c41a5885f681 8 *
meriac 0:c41a5885f681 9 * Licensed under the Apache License, Version 2.0 (the "License");
meriac 0:c41a5885f681 10 * you may not use this file except in compliance with the License.
meriac 0:c41a5885f681 11 * You may obtain a copy of the License at
meriac 0:c41a5885f681 12 *
meriac 0:c41a5885f681 13 * http://www.apache.org/licenses/LICENSE-2.0
meriac 0:c41a5885f681 14 *
meriac 0:c41a5885f681 15 * Unless required by applicable law or agreed to in writing, software
meriac 0:c41a5885f681 16 * distributed under the License is distributed on an "AS IS" BASIS,
meriac 0:c41a5885f681 17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
meriac 0:c41a5885f681 18 * See the License for the specific language governing permissions and
meriac 0:c41a5885f681 19 * limitations under the License.
meriac 0:c41a5885f681 20 */
meriac 0:c41a5885f681 21
meriac 0:c41a5885f681 22 #include <mbed.h>
meriac 0:c41a5885f681 23 #include "rgb_sensor_buffer.h"
meriac 0:c41a5885f681 24
meriac 7:bc856471c871 25 #define DEBUG
meriac 7:bc856471c871 26
meriac 7:bc856471c871 27 #define RGB_TRESHOLD 220
meriac 0:c41a5885f681 28 #define COUNT(x) (sizeof(x)/sizeof(x[0]))
meriac 0:c41a5885f681 29 #define RGB_VALUES 512
meriac 0:c41a5885f681 30
meriac 0:c41a5885f681 31 /* serial console */
meriac 0:c41a5885f681 32 static TRGB g_buffer[RGB_VALUES];
meriac 0:c41a5885f681 33 static int g_median[RGB_VALUES];
meriac 0:c41a5885f681 34 static Serial console(USBTX, USBRX);
meriac 0:c41a5885f681 35
meriac 0:c41a5885f681 36 #ifdef DEBUG
meriac 0:c41a5885f681 37 static void rgb_print(const TRGB &color)
meriac 0:c41a5885f681 38 {
meriac 0:c41a5885f681 39 int i;
meriac 0:c41a5885f681 40
meriac 0:c41a5885f681 41 console.printf("\t[");
meriac 0:c41a5885f681 42 for(i=0; i<COUNT(color.data); i++)
meriac 0:c41a5885f681 43 console.printf("%s%4i", i?",":"", color.data[i] / RGB_OVERSAMPLING);
meriac 0:c41a5885f681 44 console.printf("]");
meriac 0:c41a5885f681 45 }
meriac 0:c41a5885f681 46 #endif/*DEBUG*/
meriac 0:c41a5885f681 47
meriac 0:c41a5885f681 48 static int median_compare(const void* a, const void *b)
meriac 0:c41a5885f681 49 {
meriac 0:c41a5885f681 50 return *((int*)a) - *((int*)b);
meriac 0:c41a5885f681 51 }
meriac 0:c41a5885f681 52
meriac 0:c41a5885f681 53 static bool median(TRGB &color, int count)
meriac 0:c41a5885f681 54 {
meriac 0:c41a5885f681 55 int channel, i;
meriac 0:c41a5885f681 56
meriac 0:c41a5885f681 57 if(count<=0)
meriac 0:c41a5885f681 58 return false;
meriac 0:c41a5885f681 59
meriac 0:c41a5885f681 60 /* sort all three RGB channels to get median */
meriac 0:c41a5885f681 61 for(channel=0; channel<3; channel++)
meriac 0:c41a5885f681 62 {
meriac 0:c41a5885f681 63 for(i=0; i<count; i++)
meriac 0:c41a5885f681 64 g_median[i] = g_buffer[i].data[channel];
meriac 0:c41a5885f681 65
meriac 0:c41a5885f681 66 qsort(&g_median, count, sizeof(g_median[0]), &median_compare);
meriac 0:c41a5885f681 67
meriac 0:c41a5885f681 68 color.data[channel] = g_median[count/2];
meriac 0:c41a5885f681 69 }
meriac 0:c41a5885f681 70
meriac 0:c41a5885f681 71 return true;
meriac 0:c41a5885f681 72 }
meriac 0:c41a5885f681 73
meriac 0:c41a5885f681 74
meriac 0:c41a5885f681 75 int main() {
meriac 5:91ca771eff16 76 int res;
meriac 3:a4e4f4414533 77 double magnitude;
meriac 0:c41a5885f681 78 TRGB color;
meriac 0:c41a5885f681 79
meriac 0:c41a5885f681 80 console.baud(115200);
meriac 0:c41a5885f681 81
meriac 0:c41a5885f681 82 /* R,G,B pins and ADC for light dependent resistor */
meriac 0:c41a5885f681 83 RGB_SensorBuffer rgb(p23,p24,p25,p20);
meriac 0:c41a5885f681 84
meriac 0:c41a5885f681 85 /* needed for time measurement */
meriac 0:c41a5885f681 86 Timer timer;
meriac 0:c41a5885f681 87
meriac 0:c41a5885f681 88 while(1) {
meriac 0:c41a5885f681 89
meriac 0:c41a5885f681 90 /* start four channel RGB conversion */
meriac 0:c41a5885f681 91 timer.reset();
meriac 0:c41a5885f681 92 timer.start();
meriac 0:c41a5885f681 93
meriac 0:c41a5885f681 94 res = rgb.trigger(g_buffer, COUNT(g_buffer), RGB_TRESHOLD);
meriac 0:c41a5885f681 95
meriac 0:c41a5885f681 96 /* stop time measurement */
meriac 0:c41a5885f681 97 timer.stop();
meriac 0:c41a5885f681 98
meriac 0:c41a5885f681 99 if(res<=0)
meriac 0:c41a5885f681 100 {
meriac 0:c41a5885f681 101 console.printf("// failed to capture RGB values (%i)\r\n", res);
meriac 0:c41a5885f681 102 while(1);
meriac 0:c41a5885f681 103 }
meriac 0:c41a5885f681 104
meriac 0:c41a5885f681 105 /* calculate RGB median */
meriac 0:c41a5885f681 106 median(color, res);
meriac 0:c41a5885f681 107 /* print normalized median */
meriac 4:a4538586c75e 108 magnitude = sqrt(
meriac 4:a4538586c75e 109 ( (double)color.ch.red * color.ch.red )+
meriac 4:a4538586c75e 110 ( (double)color.ch.green * color.ch.green )+
meriac 4:a4538586c75e 111 ( (double)color.ch.blue * color.ch.blue )
meriac 4:a4538586c75e 112 );
meriac 2:f72e7a4d7395 113 console.printf("\t[%1.4f,%1.4f,%1.4f,%5i], // %i values in %ims (%i/s)\n\r",
meriac 3:a4e4f4414533 114 color.ch.red / magnitude,
meriac 3:a4e4f4414533 115 color.ch.green / magnitude,
meriac 3:a4e4f4414533 116 color.ch.blue / magnitude,
meriac 3:a4e4f4414533 117 (int)((magnitude / RGB_OVERSAMPLING)+0.5),
meriac 0:c41a5885f681 118 res,
meriac 0:c41a5885f681 119 timer.read_ms(),
meriac 0:c41a5885f681 120 (res*1000UL)/timer.read_ms()
meriac 0:c41a5885f681 121 );
meriac 0:c41a5885f681 122
meriac 0:c41a5885f681 123 #ifdef DEBUG
meriac 5:91ca771eff16 124 int i;
meriac 0:c41a5885f681 125 console.printf("\r\nvar test = [\r\n",
meriac 0:c41a5885f681 126 res,
meriac 0:c41a5885f681 127 timer.read_ms(),
meriac 0:c41a5885f681 128 (res*1000UL)/timer.read_ms());
meriac 0:c41a5885f681 129
meriac 0:c41a5885f681 130 for(i=0; i<res; i++)
meriac 0:c41a5885f681 131 {
meriac 0:c41a5885f681 132 rgb_print(g_buffer[i]);
meriac 0:c41a5885f681 133 console.printf(i<(res-1) ? ",\r\n":"];\r\n\r\n");
meriac 0:c41a5885f681 134 }
meriac 0:c41a5885f681 135 #endif/*DEBUG*/
meriac 0:c41a5885f681 136
meriac 0:c41a5885f681 137 }
meriac 0:c41a5885f681 138 }