MSP430 reduce clock speed

[Pookie 0]

Hey everyone,

I am trying to reduce the power consumption of my msp430FR4133 by reducing the clock speed from 8MHZ.

I am using the http://annem.github.io/ADXL362/ example code as a base which sets the default clock speed to 8MHZ.

I have read that the Wiring.c file defines the clock speed but I cannot find where F_CPU is defined.

Any help would be greatly appreciated    

thanks.

[B@tto 51]

Hi,

If I'm not wrong, F_CPU is defined in boards.txt

[energia 485]

Correct. F_CPU configuration in boards.txt defines the clock speed the MSP430 runs at. With that said, reducing the clock speed to 8 MHz is probably not going to do much in term s of power consumption. In your Sketch try calling sleep() or sleepSeconds() instead of delay. This will put the MSP430 in it's lowers power mode. Also make sure that you are not driving any LED's etc that consume considerable power. Also for optimal power set al unused I/O's to OUTPUT HIGH in setup using pinMode(). Do this unless it is driving an LED or some other enable pin that turns on a high power consumer peripheral of course.

Robert

[Pookie 0]

Thanks guys, Very helpful.