Saturday, July 12, 2014

A Simple PowerPoint Control Foot Switch

As a guitarist in a praise & worship session, I will have problem flipping my lyrics with chords on the paper while I'm playing. I have to pause a little while and quickly flip the pages or press enter on my laptop if the lyrics is in the PowerPoint slides. This will cause a moment of interruption on my strumming. In order to solve this problem when I'm using my laptop to refer the chords and lyrics, I built a simple foot switch control to change the slides using an al'cheapo USB keypad which you can get it from the computer shop with less than RM20.
 My PowerPoint Foot Switch Control Box

A generic USB keypad
First I did was to find our which of the keys are for the 'next' and 'previous' button slide controls. Just plug in the USB and allow few seconds to register the USB device. Then on the PowerPoint presentation mode, press any keys to find out which one that controls the next and previous slides. Then I disassembled the keypad and soldered two momentarily push buttons to the keypad lines. Additionally I soldered the 'Num Lock' button to external push button and USB connector at the rear of the box. Well these are not necessary and depends on you. I bought a box that fits everything in and labelled them accordingly. 
Solder wires on the keys that control the next & previous slide
Solder wires to the push buttons
USB connector and 'Num Lock' push button
Generally it works very well as expected. And is hands-free device! And I built this with less than RM35 (USD11) inclusive of the USB keypad and the box. 
Jamming session