What’s a robot that cannot talk?! Actually text-to-speech is very useful for almost any project. The Parallax Emic 2 is a great device that can give your project speech! This post is based on the 10.0.10586 IoT build, please make sure you are on that build or greater.
The Pi has a few serial ports, in this case I am hooked to the pins 8 and 10. These are the TXD0 and RXD0 (transmit and receive) pins. In the SerialDevice.GetDeviceSelector you use the UART0.
Here are the pins and connections (pretty simple send to the receive and receive to the send AND of course power):
Attached is the code, enjoy!