How to get Arduino Mini Pro 3.3 V consume few amps on sleep

Hi all,

Could anyone please tell me how to get the sparkfun arduino mini pro 3.3 board goes to sleep at 10 micro amps or 30 micro amps or so on batteries?

On the description below, I disabled the 2 LEDs and regulator. I also used Rocket Scream sleep library in the code. However, I could not get the arduino board to sleep at a few micro amps as people claimed. Right now, it’s sleeping at 220 micro amp. My goal is to get to about 10 or 30 micro amps or so. I wonder what important step that I missed in the work.

Thanks alot

A.H.

Hardware:

https://lowpowerlab.com/forum/index.php … 1162;image

Code:

// **** INCLUDES *****
#include "LowPower.h"

void setup()
{
    // No setup is required for this library
}

void loop() 
{
    // Enter power down state for 8 s with ADC and BOD module disabled
    LowPower.powerDown(SLEEP_8S, ADC_OFF, BOD_OFF);  
    
    // Do something here
    // Example: Read sensor, data logging, data transmission.
}

http://www.gammon.com.au/power is an excellent tutorial on power saving techniques with ATMegas. If you use all the tricks mentioned you can get the sleep power consumption down to about 100 nA.

To do that on the Pro Mini, you will need to remove the voltage regulator.

Hi,

Thanks for the reply.

I got to 97micro amps when measure between Raw and Gnd pins. However, I need to get it lower to around 10 to 40 micro amp. I dont know how. I already removed Leds and regulator.

AH

Then you may not have read that tutorial well enough. He also suggests to disable the Brown-out reset, internal voltage reference, adc. And may be a few more that I forgot. Or change the fuse bits to make it run on the internal oscilator.

A big part also depends on how you measure that small current. Multimeters connected in series add resistance into the circuit and have a voltage drop when current flows through it. The low current setting often have a large value shunt resistor so the voltage drop is larger. This also reduces the voltage that is available for the device under test. It may fail to operate or only work intermittently faking the results.

Read more about how this is a problem with most multimeters, and a tool to get more reliable readings:

Article:

http://alternatezone.com/electronics/uc … rticle.pdf

The tool: buy or build yourself

http://www.eevblog.com/projects/ucurrent/

Thank you !

AustinH:
Hi,

Thanks for the reply.

I got to 97micro amps when measure between Raw and Gnd pins. …

This makes me wonder if you know how to measure current correctly. For measuring current the meter’s probes must be in series with the device under test. In other words, between the power source positive terminal and the raw pin. The way you write it above suggests that you have the meter probes parallel to the device (to Raw voltage and ground pin.) That only works for measuring voltage. Or resistance if it is unconnected to other things. Setting the mode selector switch of the meter isn’t enough, the probes must be connected in the right way.