root / quad2 / arduino / src / ros_lib / examples / IrRanger / IrRanger.pde @ c1426757
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/* |
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* rosserial IR Ranger Example |
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* |
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* This example is calibrated for the Sharp GP2D120XJ00F. |
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*/ |
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#include <ros.h> |
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#include <ros/time.h> |
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#include <sensor_msgs/Range.h> |
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ros::NodeHandle nh; |
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sensor_msgs::Range range_msg; |
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ros::Publisher pub_range( "range_data", &range_msg); |
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const int analog_pin = 0; |
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unsigned long range_timer; |
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/* |
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* getRange() - samples the analog input from the ranger |
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* and converts it into meters. |
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*/ |
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float getRange(int pin_num){ |
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int sample; |
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// Get data |
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sample = analogRead(pin_num)/4; |
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// if the ADC reading is too low, |
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// then we are really far away from anything |
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if(sample < 10) |
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return 254; // max range |
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// Magic numbers to get cm |
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sample= 1309/(sample-3); |
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return (sample - 1)/100; //convert to meters |
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} |
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char frameid[] = "/ir_ranger"; |
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void setup() |
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{ |
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nh.initNode(); |
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nh.advertise(pub_range); |
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range_msg.radiation_type = sensor_msgs::Range::INFRARED; |
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range_msg.header.frame_id = frameid; |
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range_msg.field_of_view = 0.01; |
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range_msg.min_range = 0.03; |
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range_msg.max_range = 0.4; |
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} |
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void loop() |
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{ |
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// publish the range value every 50 milliseconds |
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// since it takes that long for the sensor to stabilize |
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if ( (millis()-range_timer) > 50){ |
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range_msg.range = getRange(analog_pin); |
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range_msg.header.stamp = nh.now(); |
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pub_range.publish(&range_msg); |
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range_timer = millis() + 50; |
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} |
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nh.spinOnce(); |
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} |
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