Turning old smartphones into anti-burglary devices and baby monitors

With 1bn smartphones lying idle in the US, meet the companies repurposing old smartphones into sensors and security cameras in a bid to tackle e-waste

If Jim Poss hadn't dropped his phone in the bath while bathing his son, he might never have hit upon the idea for his business. While researching a cheap replacement for his waterlogged iPhone, he had an epiphany: the used phones sold online for $60 (45) or less could be repurposed as Internet of Things sensors and used to form flexible, low-cost security and vehicle telematics systems.

Related: Apple announces new recycling program as interest in green gadgets grows