Power is an issue in embedded system design, both for hardware and software designers. The issue will not be going away in the near future. If you are not tasked with designing in power management on your current project, you will on the next one.

Smart phones are ubiquitous and it is worth considering how their design has been influenced by consideration of power.

The firms designing smartphones are highly motivated to address power management issues. User satisfaction is strongly influenced by battery life. And satisfied users result in more phone sales. But how would it be if they did not pay attention to this matter? First off, the phone would be a whole lot bigger and heavier, as it would need to accommodate a much larger battery in order to offer useful usage time. Second, as the device would tend to run rather hot, it would probably need a cooling fan!

This is all very fanciful, but much closer to the real world than you might think. Here is a real conversation that I witnessed, which is only slightly paraphrased:

"Hey guys - I got a new phone."

"What's it like?"

"It's just like an iPhone, but much cheaper and even better."

"Better?"

"Yes. It can take two SIM cards, so I can use the phone for both business and personal calls. No more carrying two phones."

"Cool. Where did you get it?"

"On eBay. It came from China."

"Sounds good. Any downsides?"

"Well... it is a bit power hungry."

"How bad? What's the battery life?"

"About three hours."

"$%&&@!!!"

"But it's OK. They supply two additional batteries. It's really great."

I think this happy customer gets my "Geek of the Week" award.

Colin Walls is an Embedded Software Technologist at Mentor Graphics’ Embedded Software Division.

eletter-01-16-2018

eletter-01-17-2018