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Topic: ATMega328P sleep mode (Read 5 times) previous topic - next topic

Jack Christensen

Cool, but at the same time 98uA is a lot higher than what I was reading. I just had an ATmega328P on a breadboard, with only the LED and switch hooked to it. (In addition to the essentials that is: a crystal, bypass caps, reset switch). Might there be something else drawing current?
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

fbriggs4

yeah, I know I am doing something wrong but I cant quite figure it out yet. My breadboard is bare except for the 328P, capacitors, 32.768 crystal and a 10k resistor on the reset pin. I remove the programmer completely and then power it with a lipo battery. What boot loader are you using? I have an ISP programmer, do I need to use that to change any fuse settings?

Jack Christensen

What's the 32.768kHz crystal for, are you using the Low-Freq Xtal Osc as the system clock?

I have the 10K pullup on the reset pin too, that should not pose a problem. I'm using the standard Uno Optiboot bootloader. Actually I'm using westfw's beta, but should be same difference for this purpose. Standard Uno fuses too:

Code: [Select]
uno.bootloader.low_fuses=0xff
uno.bootloader.high_fuses=0xde
uno.bootloader.extended_fuses=0x05
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

48X24X48X

The brownout detect consumes about 20uA++. The default bootloader enables them.
You can either choose to hardware disable them or do it on the fly using software.

But, somewhere else is sucking that extra 70uA++.

fbriggs4

This is great, with your suggestions I got it down to 0.2uA! I was orginally using the internal 8MHz bootloader found in the Arduino tutorial, I changed that to the standard UNO bootloader and replaced the crytal with a 16MHz which did the trick. No matter what I did with the other bootloader I could not get consumption below 1mah. I am using the 32.768 khz crystal for a timer which I am hoping to get to run for as much as a year or more before it overflows and wakes up.

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