iPod and iPhone inventor Tony Fadell on start-ups and screw-ups

Tony Fadell is an American engineer and designer who was instrumental in the creation of the the iPod and iPhone during his time at Apple. In fact, he's often referred to as "the father of the iPod", and was co-creator of the iPhone - developing three generations of it. He went on to co-found Nest Labs, with its revolutionary smart-thermostat, which was eventually sold to Google for US$3.2 billion in 2014. But while his career in Silicon Valley has had some spectacular highs, it's also had some some lows. He's taken the lessons he learned the hard way, stories of failed ventures and screw-ups, and advice about sticking to your vision and backing yourself and your product, and compiled them into a new book called Build: An Unorthodox Guide to Making Things Worth Making. He tells Kathryn how he started out tinkering with computers, and ended up making things that changed the world.