Some of these modules come with pins soldered in that top right corner, so you don’t have to solder anything. You would simply connect a jumper wire to that pin that is highlighted in red (see Figure below). With my particular sensor I had to solder a small wire.
Here’s how it looks, now if you supply 3.3V through that red wire your module works at 3.3V.
Created: 2015-03-07 23:49:44 - Hits: 3083