My article describing how to add a pushbutton power switch to your embedded systems project has been published in the November 2014 issue of Nuts and Volts Magazine. The title is “Toss the Toggle” and here is an excerpt:
Most electronic devices today have a single button you push to turn them on and off. Think of your cell phone, laptop, and even your TV. There is no toggle to flip, no knob to turn back and forth, nor slide switch to move. So, how do you get one of these power buttons into your project so your latest gadget can sit next to your other devices without the embarrassment of a toggle or slide switch?
Microprocessors drive most of our devices, and many of these processors have the ability to go into a low power sleep mode. In this state, the processor can still respond to an external signal such as a button press. When you combine that with some circuitry to control power to peripheral devices such as displays, radios, and servos, you have a system that can turn itself on and off without much additional hardware. The December 2013 issue of Nuts & Volts described an add-on solid-state power switch from Pololu which performs a similar function. As a regular customer of Pololu, I have been aware of this module for a while. However, I wanted a cheaper, more flexible, and integrated solution that wouldn’t require me to stock another part. If you’re using a microprocessor and you’re in control of the hardware and software design of your system, you can get this power control capability at little to no extra cost in money or board space.
See the full article here: Toss the Toggle.
Happy coding !