Recently I got a chance to play around with a "Makey Makey", after a few hours of entertainment I was inspired to recreate its functionality with LabVIEW. Makey Makey is an invention kit for the 21st century. It allows you to turn everyday objects into touchpads and combine them with the internet. It's a simple Invention Kit for Beginners and Experts doing art, engineering, and everything in between. In my project, I use a WF32 and LabVIEW to recreate some of the basic functionality. In my picture, I show a simple controller I made to work with my Makey Makey, my instructable "How to make a simple controller that you can use with LabVIEW" details how I built it and includes a LabVIEW VI that will allow you to use this type of controller to control boolean inputs in any VI. For more Instructables like this one check out my "DIY Makey Makey collection".
Step 1: Materials
Step 2: Circuit Setup
First, connect the 3.3V pin on the WF32 to the positive bus on one side of your breadboard and then connect the negative bus on the same side to the ground(GND) pin. Next use header pins to attach 12 gator clips to your breadboard on the opposite side of your breadboard.
Next, run 2 1MΩ resistors in series from each of the gator clip connections to the voltage bus. Then, connect each strip connected to a gator clip to an analog input on the WF32. Finally, use a grounding strap to connect ground yourself by connecting it to the ground bus.
Finally, use a grounding strap to connect ground yourself by connecting it to the ground bus.
This circuit works as a voltage divider (simple drawing shown at the bottom of the picture above), with one of the resistors (R1) being the 2 1MΩ resistors in series and the second resisor(R2) is the resistance of your body. The Switch shown above is closed when you complete the circuit. Let's say you hooked the gator clip to a banana when you touch the banana you are closing the switch and lowering the voltage read by the analog in of the WF32(Vo). In the next step I will show you how to use LabVIEW to detect this drop in Voltage.
Step 3: LabVIEW Code
First, download and unzip and open the MakeyMakey_project zip file attached below. Once this project is opened you will need to input the com port of your WF32 and then set all 12 analog channels.
Next, set the mouse action that you want for each channel, the options are shown in the picture above.
Finally, you will need to set the keyboard action performed. The possible actions are shown above.
In the LabVIEW code above I use an analog read to get the voltage values from each of the analog inputs on the WF32. I then check to see if the Volage is less than a certain threshold value. On the front panel, I set my threshold value to 2.5. This is because I know that when I touch the button and complete the circuit the value will drop below 2.5, the boolean output value will then become true and that particular action will execute.
Step 4: The End
Thank you for reading my instructable, if you are interested in making this project yourself but don't have the right supplies you can purchase the LabVIEW physical computing kit with chipKIT WF32. This kit includes a copy of LabVIEW 2014 home edition, a WF32, and everything you will need to run LINX 3.0 and start making projects. Also make sure to check out the Makey Makey, sure to provide hours of entertainment. Please comment with any questions or comments you may have. For more Instructables like this one check out my "DIY Makey Makey collection".