Diff: examples/Clapper.cpp

Revision:

0:06fc856e99ca

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/Clapper.cpp	Fri Aug 19 09:06:16 2011 +0000
@@ -0,0 +1,89 @@
+//#define COMPILE_CLAPPER_CODE_ROSSERIAL
+#ifdef  COMPILE_CLAPPER_CODE_ROSSERIAL
+
+/*
+ * rosserial Clapper Example
+ *
+ * This code is a very simple example of the kinds of
+ * custom sensors that you can easily set up with rosserial
+ * and Arduino.  This code uses a microphone attached to
+ * analog pin 5 detect two claps (2 loud sounds).
+ * You can use this clapper, for example, to command a robot
+ * in the area to come do your bidding.
+ */
+
+#include <ros.h>
+#include <std_msgs/Empty.h>
+
+ros::NodeHandle  nh;
+
+std_msgs::Empty clap_msg;
+ros::Publisher p("clap", &clap_msg);
+
+enum clapper_state { clap1, clap_one_waiting,  pause, clap2};
+clapper_state clap;
+
+int volume_thresh = 200;  //a clap sound needs to be:
+//abs(clap_volume) > average noise + volume_thresh
+AnalogIn mic_pin(p20);
+int adc_ave=0;
+
+Timer t;
+int main() {
+    t.start();
+    nh.initNode();
+
+    nh.advertise(p);
+
+    //measure the average volume of the noise in the area
+    for (int i =0; i<10; i++) adc_ave += mic_pin.read_u16();
+    adc_ave /= 10;
+
+    long event_timer = 0;
+
+    while (1) {
+        int mic_val = 0;
+        for (int i=0; i<4; i++) mic_val += mic_pin.read_u16();
+
+        mic_val = mic_val/4-adc_ave;
+
+        switch (clap) {
+            case clap1:
+                if (abs(mic_val) > volume_thresh) {
+                    clap = clap_one_waiting;
+                    event_timer = t.read_ms();
+                }
+                break;
+            case clap_one_waiting:
+                if ( (abs(mic_val) < 30) && ( (t.read_ms()- event_timer) > 20 ) ) {
+                    clap= pause;
+                    event_timer = t.read_ms();
+
+                }
+                break;
+            case pause: // make sure there is a pause between
+                // the loud sounds
+                if ( mic_val > volume_thresh) {
+                    clap = clap1;
+
+                } else if ( (t.read_ms()-event_timer)> 60)  {
+                    clap = clap2;
+                    event_timer = t.read_ms();
+
+                }
+                break;
+            case clap2:
+                if (abs(mic_val) > volume_thresh) { //we have got a double clap!
+                    clap = clap1;
+                    p.publish(&clap_msg);
+                } else if ( (t.read_ms()-event_timer)> 200) {
+                    clap= clap1; // no clap detected, reset state machine
+                }
+
+                break;
+        }
+        nh.spinOnce();
+    }
+}
+
+#endif
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