Remote control application

Assumes a NXT robot configuration alike the TriBot.

Usage

• Enter the COM port number and press the connect-button.
• Move the vertical scrollbar up to set the robot into a forward direction. Down to reverse.
• Move the horizontal scrollbar left or right to steer in the desired direction.

Code

• Place a Label in the lower left corner of the form and change its Text property to "COM".
• Add a TextBox following the label, change its name to txtComPort, set its Text property to "40" (or whatever COM port your NXT connects through) and resize it to fit the text.
• Add a Button following the txtComPort, change its name to btnConnect and change its Text property to "Connect".
• Add a second Button following the btnConnect, change its name to btnDisconnect and change its Text property to "Disconnect".
• Add a third Button following the btnDisconnect, change its name to btnIdle and change its Text property to "Idle".
• For all 5 controls, change their Anchor property to "Bottom, Left".
• Add a Panel to the form, change its name to remoteControlPanel, change its BorderStyle property to FixedSingle, and resize it to fill the upper part of the form (see image above).
• Change the Anchor property to "Top, Bottom, Left, Right".
• Add a VScrollBar to the panel (not the form!) and change its name to vbarPower. This scrollbar determines the power of the NXT robot. Change its Minimum property to -100 (while keeping the Maximum property at 100). Change its Dock property to Right.
• Add a HScrollBar to the panel and change its name to hbarTurnRatio. This scrollbar determines the turnRatio of the NXT robot. Change its Maximum property to 10 and its Minimum property to -10. You could set them to 100 and -100, but that would only result in a difficult steering. You may also consider changing the LargeChange property to 1. Lastly change its Dock property to Bottom.
• Double click on the three buttons to create Click eventhandlers.
• Click on the two scrollbars and a ValueChanged eventhandler on each.

Then add the following code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

using NKH.MindSqualls;

namespace NxtRemote2
{
    public partial class Form1: Form
    {
        private NxtBrick brick;
        private NxtMotorSync motorPair;

        public Form1()
        {
            InitializeComponent();

            this.Text = "Disconnected";
        }

        private void btnConnect_Click(object sender, EventArgs e)
        {
            try
            {
                byte comPort = byte.Parse(this.txtComPort.Text);
                brick = new NxtBrick(comPort);

                brick.MotorB = new NxtMotor();
                brick.MotorC = new NxtMotor();
                motorPair = new NxtMotorSync(brick.MotorB, brick.MotorC);

                brick.Connect();

                this.Text = "Connected: " + brick.Name;
            }
            catch
            {
                Disconnect();
            }
        }

        private void btnDisconnect_Click(object sender, EventArgs e)
        {
            Disconnect();
        }

        private void btnIdle_Click(object sender, EventArgs e)
        {
            Idle();
        }

        private void Idle()
        {
            if (brick != null && brick.IsConnected)
                motorPair.Idle();

            this.vbarPower.Value = 0;
            this.hbarTurnRatio.Value = 0;
        }

        private void Disconnect()
        {
            Idle();

            if (brick != null && brick.IsConnected)
                brick.Disconnect();

            brick = null;
            motorPair = null;

            this.Text = "Disconnected";
        }

        private void hbarTurnRatio_ValueChanged(object sender, EventArgs e)
        {
            ValueChanged();
        }

        private void vbarPower_ValueChanged(object sender, EventArgs e)
        {
            ValueChanged();
        }

        private void ValueChanged()
        {
            if (brick != null && brick.IsConnected)
            {
                sbyte power = (sbyte) (-this.vbarPower.Value);
                sbyte turnRatio = (sbyte) this.hbarTurnRatio.Value;

                if (power < 0) turnRatio = (sbyte) (-turnRatio);

                motorPair.Run(power, 0, turnRatio);
            }
        }
    }
}

Download

NxtRemote2.zip

http://www.mindsqualls.net