pro-mini power_down current

Development Boards MicroMod
1

I try to develop a project on the sparkfun pro-mini 328/ 3,3V, 8MHz.

This project is highly dependent on most power-save.

But i measure 0,3mA current in Power down mode.

The power indicator LED is removed already.

What makes this high current in power down mode (sleep) ?

2

I’ve recently begun some projects using power down states and hardware interrupts, and saw similar results to yours. I’m just using the ATMega chips, not on a dev board, but there are a few things you can do to reduce current usage further. You can disable the watchdog timer (shoudlnt be needed if you use hardware interrupts), reduce clock speed, reduce voltage, turn off brown out detector, turning off other unused features such as other timers, ADC, etc. You may be limited since you’re using a dev board on some of these, such as you wont be able to drop voltage much due to the onboard regulator, same with changing clock speed of the chip.

Also, what power down state are you using?

3

Hi krphop, thanks for reply!

I do not use the “raw” input for power, but provides the Vcc directly to the board, bypassing the regulator.

Never activated the watchdog, so i assume WD is off, but i’m not sure.

I will try your remaining recommendations, but i do not know how

to switch them off yet:

“turn off brown out detector”

Even do not know what’s a “brown out detector”

"turning off other unused features such as

other timers,

ADC, etc."

I presumed that all the above stuff is inactive in the most powersave sleep mode. I use this sequence to set sleep mode:

set_sleep_mode(SLEEP_MODE_PWR_DOWN);

sleep_enable();

attachInterrupt(0,toolIrqEvent, LOW);

sleep_mode();

cheers wally

4

Working with all LED’s removed i still measure 0,3mA in sleep mode.

Removing the Voltageregulatur recuced the current from 0,3mA to 0,1mA

in sleep mode power_down.

This is still too much, but maybe the lowest current to achieve with 3,3Volts,

8Mhz external quarz on sparkfun pro-mini board /328.

In code i use the following software powerreduction commands:

power_adc_disable();

power_spi_disable();

power_timer0_disable();

power_timer1_disable();

power_timer2_disable();

power_twi_disable();

sleep_bod_disable();

Can anybody confirm the current of 0,1mA as the lowest achievable in this configuration please or is there another method to reduce power under 0,1mA.

cheers wally