LAS VEGAS -- Ever wish the GPS on your smartphone worked inside a shopping mall or in a downtown chasm surrounded by office towers?

InvenSense, which makes gyroscopes and other motion sensors, plans to sell chips within a couple of years that let smartphones guide their owners up and down escalators, through subway stations and up to specific cubicles within skyscrapers -- all places that GPS signals do not currently work well.

CEO Behrooz Abdi told Reuters at the Consumer Electronics Show in Las Vegas on Wednesday his engineers are working on electronic barometers capable of detecting changes in altitude as small as standing up from a chair.

"Today, GPS is accurate outdoors if you're in a big city like Las Vegas with wide streets and buildings not too close together. If you're in Manhattan, your GPS is not very accurate. Worse yet if you're inside a building," Abdi said.

Combining barometric chips that sense minor changes in altitude with sensors that can keep track of movement will allow phones to guide their owners through places where GPS signals are out of reach.

"The products we're looking at will be accurate to the sub-meter. At some point in the future it will be accurate enough to tell you whether you're sitting or standing," Abdi added.

InvenSense's gyroscopes and other motion-tracking technology are currently used in mobile gadgets including Samsung's Galaxy S3, Amazon's Kindle Fire HD and