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Topic: Atmega328 operations with a low voltage (Read 2 times) previous topic - next topic

Jack Christensen


I guess I struggle a bit with the idea of simply running off of batteries - just seems wrong somehow.  I know it's ok (as long as you're within the spec of the hardware you're using) but it... well... it's just a mind thing I guess. I'll just have to work on that :-)

You're probably right.  Sure a large range of acceptable voltages.  And they are are hardy little buggers too.


The datasheet does caution against letting the supply voltage get too low, memory can be corrupted, but they have the solution built-in, namely the brown-out detector. Set the fuses so that it kicks in at a reasonable point given supply voltage and clock frequency.
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

maniacbug

Yup, I run 2xAA's, 8MHz crystal, BOD at 1.8V, and I've had units lasting for months.

smeezekitty



I guess I struggle a bit with the idea of simply running off of batteries - just seems wrong somehow.  I know it's ok (as long as you're within the spec of the hardware you're using) but it... well... it's just a mind thing I guess. I'll just have to work on that :-)

You're probably right.  Sure a large range of acceptable voltages.  And they are are hardy little buggers too.


The datasheet does caution against letting the supply voltage get too low, memory can be corrupted, but they have the solution built-in, namely the brown-out detector. Set the fuses so that it kicks in at a reasonable point given supply voltage and clock frequency.

I think this is mostly a problem if you are writing to flash to eeprom during a low voltage condition.
My personal experience is that they go into a reset loop about 15% below the datasheet minimum for that frequency.
Avoid throwing electronics out as you or someone else might need them for parts or use.
Solid state rectifiers are the only REAL rectifiers.
Resistors for LEDS!

funkyguy4000

Oh wow lots of input!
The project that i'm doing seems almost identical to brads.

Quote
I am careful to set the system clock speed according to the supply voltage, but other than that, I'm not aware of major issues.


So how would i do that?  Would i just upload my program and then the chip runs at the speed according to the supply voltage it is getting?

Accelerate to 88 miles per hour.

smeezekitty


Oh wow lots of input!
The project that i'm doing seems almost identical to brads.

Quote
I am careful to set the system clock speed according to the supply voltage, but other than that, I'm not aware of major issues.


So how would i do that?  Would i just upload my program and then the chip runs at the speed according to the supply voltage it is getting?



You have to set the clock speed for the lowest voltage you intend to operate at.
Avoid throwing electronics out as you or someone else might need them for parts or use.
Solid state rectifiers are the only REAL rectifiers.
Resistors for LEDS!

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