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LRF (Laser Range Finder) sensor using SerialPort - Detect LRF distance through SerialPort


1. Start "SPL script editor for MSRDS" and add SPL simulation script
  1. Add script on the editor as follows.

       
    MFEmulator    emul1
	/TargetEmulator:SPLMFConsoleEmulator
	/Procedure_I2CWrite:proc_i2c_write

StartSimulationEngine  "SimState/basicenv4.xml"

AddDifferentialDriveEntity    base1

AddLaserRangeFinderEntity    lrf1
	/Position:0  0.4  0
	/ParentEntity:base1
	/Procedure_SensorNotify:proc_lrf

FlushScript  

sendBytes = Util.CreateArrayByte(361)

skip_count = 4

ready_flag = false

procedure  proc_lrf
	
	if (skip_count <= 0 && ready_flag)
	{
		lrfbuff = value.DistanceMeasurements
	
		for (i = 0; i < 361; i++)
		{
			//convert scalse to byte 8000 -> 250
			distance = lrfbuff[i] / 32
			sendBytes[i] = Util.ToByte(distance)
		}
		
		emul1.SendToSerialPort("COM3", sendBytes)
		
		d180 = lrfbuff[180]
		print d180
		
		skip_count = 4
	}
	
	skip_count--
end 

procedure  proc_i2c_write
	
	ready_flag = true

	if (value.Id == "i2c1")
	{
		command_type = value.ReceivedBytes[0]
		
		if (command_type == 1)
		{		
			distance = value.ReceivedBytes[1]
			power = value.ReceivedBytes[2]
	
			power = power - 100

			distance = Util.ToDouble(distance / 10.0)
			power = Util.ToDouble(power / 100.0)

			print "Distance -> " + distance.ToString() + " m / Power -> " + power.ToString()
			
			base1.GoTo(distance, power)
		}
		else if (command_type == 2)
		{		
			degrees = value.ReceivedBytes[1]
			power = value.ReceivedBytes[2]
	
			degrees = degrees - 100
			power = power - 100

			degrees = Util.ToDouble(degrees)
			power = Util.ToDouble(power / 100.0)

			print "Degrees -> " + degrees.ToString() + " / Power -> " + power.ToString()
			
			base1.Turn(degrees, power)
		}
		else if (command_type == 4)
		{		
			left_power = value.ReceivedBytes[1]
			right_power = value.ReceivedBytes[2]
	
			left_power = left_power - 100
			right_power = right_power - 100

			left_power = Util.ToDouble(left_power / 100.0)
			right_power = Util.ToDouble(right_power / 100.0)

			print "Left -> " + left_power.ToString() + " / Right -> " + right_power.ToString()
			
			base1.Go(left_power, right_power)
		}
	}

end
    		  


  2. Save script.

  3. Press "F5" key or click "Run" icon.



2. Add a new SerialPort named "COM3" to detect LRF sensor event
  1. Clear editor box of MF application.

  2. Add below script on the editor box of MF application.



       
    I2CDevice    i2c1
	/Address:58
	/ClockRateKhz:100


SerialPort    COM3
	/PortName:COM3
	/BaudRate:9600


lrf_buff = Util.CreateArrayByte(361)

buff1 = Util.CreateArrayByte(3)

//go forwards
buff1[0] = 4
buff1[1] = 110	//0.1
buff1[2] = 110	//0.1

//make a robot move itselft
i2c1.Write(buff1)

//call procedure with the separate thread
call proc_read_lrf with concur


procedure proc_read_lrf

	while(true)
	{	
		COM3.Read(lrf_buff, 0, 361)
		
		//distance of front
		distance_180 = lrf_buff[180] * 32
		
		print "Distance [180]: " + distance_180
	}
	
end
    		  


  3. Click "Send to MF Application" button

  4. You can see the detected distance of LRF sensor is printed on the consolewindow as robot moves.



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