Diff: examples/Button_example.cpp

Revision:

0:06fc856e99ca

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/Button_example.cpp	Fri Aug 19 09:06:16 2011 +0000
@@ -0,0 +1,59 @@
+//#define COMPILE_BUTTON_EXAMPLE_CODE_ROSSERIAL
+#ifdef  COMPILE_BUTTON_EXAMPLE_CODE_ROSSERIAL
+
+/*
+ * Button Example for Rosserial
+ */
+
+#include "mbed.h"
+#include <ros.h>
+#include <std_msgs/Bool.h>
+
+
+ros::NodeHandle nh;
+
+std_msgs::Bool pushed_msg;
+ros::Publisher pub_button("pushed", &pushed_msg);
+
+DigitalIn button_pin(p8);
+DigitalOut led_pin(LED1);
+
+bool last_reading;
+long last_debounce_time=0;
+long debounce_delay=50;
+bool published = true;
+
+Timer t;
+int main() {
+    t.start();
+    nh.initNode();
+    nh.advertise(pub_button);
+
+    //Enable the pullup resistor on the button
+    button_pin.mode(PullUp);
+
+    //The button is a normally button
+    last_reading = ! button_pin;
+
+    while (1) {
+        bool reading = ! button_pin;
+
+        if (last_reading!= reading) {
+            last_debounce_time = t.read_ms();
+            published = false;
+        }
+
+        //if the button value has not changed for the debounce delay, we know its stable
+        if ( !published && (t.read_ms() - last_debounce_time)  > debounce_delay) {
+            led_pin = reading;
+            pushed_msg.data = reading;
+            pub_button.publish(&pushed_msg);
+            published = true;
+        }
+
+        last_reading = reading;
+
+        nh.spinOnce();
+    }
+}
+#endif
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