The software developed in this project allows you to build your own hardware measuring response latencies for experiments in cognitive science. For building hardware, we use Arduino microcontroller boards and sensors that come from either rapid prototyping toolkits or are custom-built. On the software side, you can connect to E-Prime using USB and the virtual serial port. In this case, use the code below mentioning serial connections. Alternatively, you can connect ANY experimental software, including DMDX, if you use an Arduino Leonardo, and let it emulate a keyboard. For that, see the Arduino Leonardo code below. We encourage porting this to other software that runs experiments. For more information, see Schubert, T. W., D’Ausilio, A., & Canto, R. (in press). Using Arduino microcontroller boards to measure response latencies. Behavior Research Methods. [http://reactiontimes.wordpress.com/arduinort/][1] ALL source code in this project published under the [GNU GPL v2 license][2]. ALL other items on this project are licensed under a [Creative Commons Attribution Share-Alike license][3], which allows for both personal and commercial derivative works, as long as they credit this project site and release their products under the same license. Note that this software is under development and should be considered as in Beta. Everything is provided as is, and we make no warranties whatsoever with respect to its functionality. By downloading the software from this page, you agree to the specified terms. [1]: http://reactiontimes.wordpress.com/arduinort/ [2]: http://www.gnu.org/licenses/old-licenses/gpl-2.0.html [3]: http://creativecommons.org/licenses/by-sa/3.0/