[PIC] minimize power consumption in microcontroller

[ruben91]

Good day everyone,

currently im doing a project, ultrasonic sensor based project. an ultrasonic range detector.
i wish to make it a portable so that it can be powered by battery. The problem here is, i wan to make it to consume less power so that the battery can last long

Is there anyway to cut off the power supply wen a particular range is met? as an example i want to make the microcontroller stop consume power if the distance detected by the sensor is more than 15 cm for 5 cycle, and microcontroller activate back if it detects distance less than 150 cm..

please kindly advise me on this..much appreciated

 

[ud23]

if the distance detected by the sensor is more than 15 cm for 5 cycle, and microcontroller activate back if it detects distance less than 150 cm..

ya now a days almost all controllers comes with low power settings like msp,pic,avr .

which controller you are going to use?

for making the controller off mean you can make controller sleep mode. and waking up from sleep mode when your condition met.

For power consumption others factor also need to calculate like your battery self discharge rate ,your sensor and ldo power consumption and other device if you have used.

 

[ruben91]

yea that wat i meant making the controller sleep mode, im using pic18f4580 currently

 

[ud23]

https://ww1.microchip.com/downloads/en/DeviceDoc/01146B_chapter 2.pdf

hope this will help you.

 

[betwixt]

I disasgree!

I see no way you can put the PIC to sleep and wake it up when it detects a shorter distance. It can not detect the distance while asleep.

Presumably you pulse the ultrasonic sound and time the echo to find the distance. The only way you can reduce consumption is to send the pulses less frequently and shut down unnecessary peripherals and pins between checks. You can speed it up again for a more responsive measurement if the distance increases. Be careful with the logic of it's operation though, bear in mind how it may be stored between uses and how this may decide whether it is in slow or fast mode.

A much better solution would be to use a timer to put it to sleep after a few seconds of use and wake it up again with an electrical signal from a button or tilt switch.

Brian.

 

[ruben91]

thanks ud23

https://ww1.microchip.com/downloads/en/DeviceDoc/01146B_chapter 2.pdf

hope this will help you.

- - - Updated - - -

thanks for your advise sir, but i have a problem here, im doing a portable sensing system for blind, since its portable i want to make it consume as less power as possible, it ther a way to doit without a switch?

I disasgree!

I see no way you can put the PIC to sleep and wake it up when it detects a shorter distance. It can not detect the distance while asleep.

Presumably you pulse the ultrasonic sound and time the echo to find the distance. The only way you can reduce consumption is to send the pulses less frequently and shut down unnecessary peripherals and pins between checks. You can speed it up again for a more responsive measurement if the distance increases. Be careful with the logic of it's operation though, bear in mind how it may be stored between uses and how this may decide whether it is in slow or fast mode.

A much better solution would be to use a timer to put it to sleep after a few seconds of use and wake it up again with an electrical signal from a button or tilt switch.

Brian.

 

[Easyrider83]

You can wake up the PIC let's say every 250ms, activate P-mosfet to supply the sensor, send echo, receive result, calculate value and then decide sleep again or continue do something.