[vc_row][vc_column width=”1/1″][vc_column_text]In this tutorial, we show a Touch Key USB Shield which is similar as Makey makey.

[/vc_column_text][vc_tour][vc_tab title=”Example to use Touch key USB Shield” tab_id=”1384052831-1-11″][vc_column_text]Touch key USB shield uses two-point touch as the way to input. When use it, we need to wire the touch end and ground end to two electrodes respectively.  When human touches the two electrodes, there will be current passing through the two electrodes due to the resistance of the human body. The touch key USB shield relies on detecting this current to check if there is any touch event.[/vc_column_text][/vc_tab][vc_tab title=”Setup” tab_id=”1384052831-2-73″][vc_column_text]1. Arduino Uno (with USB data cable)

2. Touch key USB Shield:

3. Two test cables (as the touch is sensitive to the EMI in the environment, please use the shielded cable)

54. Three coins:

[/vc_column_text][/vc_tab][vc_tab title=”Add Library to Arduino IDE and Compile Example Code” tab_id=”1384053726175-2-1″][vc_column_text]1.  Copy the test library (“USBKeyBoard“) to “libraries” under Arduino.

2. Open Arduino IDE, click “File->Examples->USBKeyBoard->Touch_Key”:

3.  Now we open a simple test code. The next step is to compile and download to Arduino:

[/vc_column_text][/vc_tab][vc_tab title=”Test” tab_id=”1384053757627-3-5″][vc_column_text]1. Wire test cables correctly and prepare to test:

(1)  Clip one end of black cable to GND of the touch USB shield, the other end left floating.

(2) One end of one red cable is clipped to A0 of the touch USB shield, and the other end is clipped to a dime.

(3)One end of another black cable is clipped to A1 of the touch USB shield, and the other end is clipped to a half dollar coin.

(4)One end of another red cable is attached to A2 of the touch USB shield, and the other end is attached to a dollar coin.

2. Test results:

We hold the floating end of the black cable by one end, and touch the coins with another hand.

(1) Touch the dime, we will observe “LED-6” turns on.

(2) Touch the half dollar coin, we will observe the “LED-5 ” turns on:

(3) Touch the dollar coin, we will see “LED-4” turns on.

(4) If we touch all three coins at the same time, we will see all three LEDs on.

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