Sometimes I skip the question. Who does not have a home projector at home? Increasingly they are more accessible economically, while evolve and allow for greater ease of use. More compact. You need only take a walk through the mall to see that this is so. Also, for what to watch on TV, maybe a projector, popcorn and our favorite series. The presentations tablets are becoming more common thanks to its interactivity. So the requirement is more common office projectors for educational purposes or for connection between devices: enabling mobility in an office, auditorium or a class without relying on a cable. These projectors with free Wi-Fi are very practical for users of mobile devices (tablets and smartphones). Both personally and leisure level; as at the enterprise level to present charts or slides. For some years, Epson projectors, along with Android devices, have an application called iProjection that allows through a smarphone or tablet and a projector to direct the image on a screen by controlling its content from the mobile phone. You can make presentations ODT, PDF or JPG photos. This is useful in a school, where the teacher can teach more agility thanks to the functionality and flexibility provided by a tablet. Without forgetting the importance in an office, during a meeting or presentation projects. Of course for this to be possible it is necessary to connect our smarphone or tablet in any way. Luckily most current devices incorporate video outputs in high definition. Usually a HDMI output at its three known variants. Whether in its normal size, microHDMI, via USB with MHL adapter or with its own adapter. It may be the case that our phone is not compatible with this type of video output, or worse, that our projector is from the Jurassic and HDMI not understand. You may not know this but the vast majority of phones offer the ability to send the video signal via composite video. This output is connected to the headphone output. So we need a jack to RCA cable 3.5 with 3 output connectors. The quality is not very good, no HD, but for most projectors or to watch a movie in DVD quality. Needless to say you must connect each connector in color (red, white, yellow) and as this is a world just does not work on your terminal without activating settings screen. And finally the USB connection can be the best option. It turns out that the most recent projectors offer free by accessing such files containing your terminal as a memory. It is the player who is responsible for making possible the reproduction of the document or file you want to see projected.