Diff: examples/IrRanger.cpp

Revision:

0:06fc856e99ca

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/IrRanger.cpp	Fri Aug 19 09:06:16 2011 +0000
@@ -0,0 +1,67 @@
+//#define COMPILE_IRRANGER_CODE_ROSSERIAL
+#ifdef  COMPILE_IRRANGER_CODE_ROSSERIAL
+
+/*
+ * rosserial IR Ranger Example
+ *
+ * This example is calibrated for the Sharp GP2D120XJ00F.
+ */
+
+#include <ros.h>
+#include <ros/time.h>
+#include <sensor_msgs/Range.h>
+
+ros::NodeHandle  nh;
+
+
+sensor_msgs::Range range_msg;
+ros::Publisher pub_range( "range_data", &range_msg);
+
+PinName analog_pin = p20;
+unsigned long range_timer;
+
+/*
+ * getRange() - samples the analog input from the ranger
+ * and converts it into meters.
+ */
+float getRange(PinName pin_num) {
+    int sample;
+    // Get data
+    sample = AnalogIn(pin_num).read_u16()/4;
+    // if the ADC reading is too low,
+    //   then we are really far away from anything
+    if (sample < 10)
+        return 254;     // max range
+    // Magic numbers to get cm
+    sample= 1309/(sample-3);
+    return (sample - 1)/100; //convert to meters
+}
+
+char frameid[] = "/ir_ranger";
+
+Timer t;
+int main() {
+    t.start();
+    nh.initNode();
+    nh.advertise(pub_range);
+
+    range_msg.radiation_type = sensor_msgs::Range::INFRARED;
+    range_msg.header.frame_id =  frameid;
+    range_msg.field_of_view = 0.01;
+    range_msg.min_range = 0.03;
+    range_msg.max_range = 0.4;
+
+    while (1) {
+        // publish the range value every 50 milliseconds
+        //   since it takes that long for the sensor to stabilize
+        if ( (t.read_ms()-range_timer) > 50) {
+            range_msg.range = getRange(analog_pin);
+            range_msg.header.stamp = nh.now();
+            pub_range.publish(&range_msg);
+            range_timer =  t.read_ms() + 50;
+        }
+        nh.spinOnce();
+    }
+}
+
+#endif
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