In this instructable we will show you how to make an easy and cheap multi touch mouse pad for your computer. 'Multi touch' means that the surface can detect more than one or two fingers as an input.
What you need is:
- Card box (size will depend on the webcam)
- Lid of a cardbox or an A4 picture frame
- Thin sturdy acrylic glass (or a similar material), A4 size
- Blanc paper, A4 size
- Tape, scissors and utility knife
Step 1: Determine Height of the Cardbox
Find a box that has a top surface of approximately A4 size. The height of the box is dependent of the type of webcam you are using. We recommend to take a box with a height of approximately 35 cm, which gives enough tolerance to be shortened later if needed. If you can't find a box with the needed dimensions, you can start from scratch by using cardboard sheets.
To find the exact right height for your webcam, you have to first download the CCV 1.2 software and connect the webcam to your computer. If needed, click on "next camera" until the software shows the right webcam.
Place the webcam at the bottom inside the box, with the camera facing straight upward. The webcam is positioned in the right way when the sides of the card box are not visible on the camera.
Next, take a blanc paper and hold it right above the camera. Move the paper up and down while looking at the camera's image in the software. Hold the piece of paper at the height where the borders of the paper have just disappeared from the camera's image, where the entire image turns white. Measure this height. In our case, the height of the box was set at 25cm.
If you are working with a box that is larger than an A4 format, we recommend to add two spare centimeters to the height that was measured, to create an edge where the paper can rest on.
Step 2: Place Webcam and Surface
Cut a small hole in a bottom corner of the box through which the cable and USB of the webcam can go. Tape the webcam to the bottom of the box, positioned in the way that was explained in step 1.
The touch surface will exist of a blanc A4 paper on top of an A4 sized acrylic glass sheet. To give more stiffness to this surface, you can tape both sheets to an A4 picture frame, or a frame you created yourself from a cardboard lid.
Place the touch surface on top of the box you created.
Step 3: Software Setup
The settings of the CCV software should be adjusted to get a right tracked image of your finger tips (see image above).
First of all select remove BG if the tracked image shows things without touching it; it should be completely black.
After getting the right tracked image, the touchpad needs to be calibrated by selecting "Enter calibration" at the right or pressing on "c".
The touch pad will work best in an environment where light comes from different directions, but it can be used in any environment with light to cause enough contrast in the shadow that is detected by the webcam.
Step 4: Use As a Mousepad
Finally download the mousedriver in order to use the touchpad as a mouse. To (de)activate the mousedriver the spacebar can be used.
Now your multi touch mousepad is ready to use!