Clapper.cpp

00001 //#define COMPILE_CLAPPER_CODE_ROSSERIAL
00002 #ifdef  COMPILE_CLAPPER_CODE_ROSSERIAL
00003 
00004 /*
00005  * rosserial Clapper Example
00006  *
00007  * This code is a very simple example of the kinds of
00008  * custom sensors that you can easily set up with rosserial
00009  * and Arduino.  This code uses a microphone attached to
00010  * analog pin 5 detect two claps (2 loud sounds).
00011  * You can use this clapper, for example, to command a robot
00012  * in the area to come do your bidding.
00013  */
00014 
00015 #include <ros.h>
00016 #include <std_msgs/Empty.h>
00017 
00018 ros::NodeHandle  nh;
00019 
00020 std_msgs::Empty clap_msg;
00021 ros::Publisher p("clap", &clap_msg);
00022 
00023 enum clapper_state { clap1, clap_one_waiting,  pause, clap2};
00024 clapper_state clap;
00025 
00026 int volume_thresh = 200;  //a clap sound needs to be:
00027 //abs(clap_volume) > average noise + volume_thresh
00028 AnalogIn mic_pin(p20);
00029 int adc_ave=0;
00030 
00031 Timer t;
00032 int main() {
00033     t.start();
00034     nh.initNode();
00035 
00036     nh.advertise(p);
00037 
00038     //measure the average volume of the noise in the area
00039     for (int i =0; i<10; i++) adc_ave += mic_pin.read_u16();
00040     adc_ave /= 10;
00041 
00042     long event_timer = 0;
00043 
00044     while (1) {
00045         int mic_val = 0;
00046         for (int i=0; i<4; i++) mic_val += mic_pin.read_u16();
00047 
00048         mic_val = mic_val/4-adc_ave;
00049 
00050         switch (clap) {
00051             case clap1:
00052                 if (abs(mic_val) > volume_thresh) {
00053                     clap = clap_one_waiting;
00054                     event_timer = t.read_ms();
00055                 }
00056                 break;
00057             case clap_one_waiting:
00058                 if ( (abs(mic_val) < 30) && ( (t.read_ms()- event_timer) > 20 ) ) {
00059                     clap= pause;
00060                     event_timer = t.read_ms();
00061 
00062                 }
00063                 break;
00064             case pause: // make sure there is a pause between
00065                 // the loud sounds
00066                 if ( mic_val > volume_thresh) {
00067                     clap = clap1;
00068 
00069                 } else if ( (t.read_ms()-event_timer)> 60)  {
00070                     clap = clap2;
00071                     event_timer = t.read_ms();
00072 
00073                 }
00074                 break;
00075             case clap2:
00076                 if (abs(mic_val) > volume_thresh) { //we have got a double clap!
00077                     clap = clap1;
00078                     p.publish(&clap_msg);
00079                 } else if ( (t.read_ms()-event_timer)> 200) {
00080                     clap= clap1; // no clap detected, reset state machine
00081                 }
00082 
00083                 break;
00084         }
00085         nh.spinOnce();
00086     }
00087 }
00088 
00089 #endif