Robot driving using I2C device - Control robot driving with UI buttons

1. Start "SPL script editor for MSRDS" and add SPL simulation script

Add below script on the editor.

MFEmulator    emul1
	/TargetEmulator:SPLMFConsoleEmulator
	/Procedure_I2CWrite:proc_i2c_write

StartSimulationEngine  "SimState/basicenv4.xml"

AddDifferentialDriveEntity    base1

FlushScript

2. Add procedure lines on the end of lines

Add below script on the editor.

MFEmulator    emul1
	/TargetEmulator:SPLMFConsoleEmulator
	/Procedure_I2CWrite:proc_i2c_write

StartSimulationEngine  "SimState/basicenv4.xml"

AddDifferentialDriveEntity    base1

FlushScript  

Procedure  proc_i2c_write
	
	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

Save script.

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

3. Convert I2C data into the degrees and power

In this tutorial, we will use three bytes to send the value of motor power and command type.
1. Byte[0] : 4 (Command type)
2. Byte[1] : Left power
3. Byte[2] : Right power

First byte is the command type and will be used to classify each drive command.
1. 1 : GoTo
2. 2 : Turn
3. 3 : GoFor
4. 4 : Go
5. 5 : Stop

Since the value range of MSRDS's motors is -1.0 ~ 1.0, we should convert byte value to these range.

Below is a conversion rule bewteen I2C data and motor power.

	
Conversion of motor power value from I2C to MSRDS:
	0 -> -1.0
	100 -> 0.0
	200 -> 1.0

Procedure "proc_i2c_write" includes this conversion logic.

4. Send data when the button is pressed

Clear editor box of MF application.

In order to send drive data when the button is pressed, add below script on the editor box of MF application.

I2CDevice    i2c1
	/Address:58
	/ClockRateKhz:100

BindGPIOButtonEvent  
	/Procedure_OnButtonDown:proc1


buff1 = Util.CreateArrayByte(3)

procedure proc1

	if (value.Button == 37)
	{
		//left
		buff1[0] = 4
		buff1[1] = 80	//-0.2
		buff1[2] = 120	//0.2

		i2c1.Write(buff1)	
	}	
	else if (value.Button == 39)
	{
		//right
		buff1[0] = 4
		buff1[1] = 120	//-0.2
		buff1[2] = 80	//0.2

		i2c1.Write(buff1)	
	}	
	else if (value.Button == 38)
	{
		//up -> go forwards
		buff1[0] = 4
		buff1[1] = 130	//0.3
		buff1[2] = 130	//0.3

		i2c1.Write(buff1)	
	}	
	else if (value.Button == 40)
	{
		//down -> backwards
		buff1[0] = 4
		buff1[1] = 70	//-0.3
		buff1[2] = 70	//-0.3

		i2c1.Write(buff1)	
	}	
	else if (value.Button == 41)
	{
		//select -> stop
		buff1[0] = 4
		buff1[1] = 100	//0.0
		buff1[2] = 100	//0.0

		i2c1.Write(buff1)	
	}	

end

Click "Send to MF Application" button

Click Up-Button to make a robot go forwards

Click Select-Button to make a robot stop

Click Down-Button to make a robot go backwards

Click Left-Button or Right-Button to make a robot turn

You can see a mobile robot is controled by emulator's button.

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