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Topic: Bare Arduino With 2xAA Batteries (3v) (Read 138 times) previous topic - next topic

Payam_sbr

Mar 08, 2018, 09:00 pm Last Edit: Mar 08, 2018, 09:07 pm by Payam_sbr
hey :)
im working on a long standing project which should be done by long sleep's and short wake times (few sec's [and once time] per day)

for some reasons i'm forced to use 3v (with a diode its less to 2.7V in my case)
atmega chip has a MIN of 1.8v for operating supply voltage.
i dont have 3v3 source because most popular voltage regulators are not good choices in long standing battery powered applications, they has a valuable quiescent current.

i'm going to use an Atmega328P and another arduino chip (Pro mini 3v3) to program the chip as a Bare Arduino. i want to know if it is a Clear job or not please? can i upload 8Mhz Bootloader for a 2.7v powered chip? may difference in voltage affects the performance?

tnx.


Edit
i checked it out that lilypad dont have a regulator and it operates at 2.7v-5.5v.
am i true? is a better bootloader?

jremington

#1
Mar 08, 2018, 09:58 pm Last Edit: Mar 08, 2018, 10:01 pm by jremington
You don't need a voltage regulator for many low voltage Arduino projects. See this tutorial. It describes a solar powered Arduino, with a supercap for energy storage, but the same principles apply to a 2xAA power source.

See also this battery powered temperature and humidity sensor project, for long term monitoring of museum climate.

Robin2

I have made a few projects that use an Atmega 328 powered directly by 2 x AA Alkaline cells. I use the internal 8MHz oscillator.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

srnet

#3
Mar 08, 2018, 10:21 pm Last Edit: Mar 08, 2018, 10:22 pm by srnet
Do remember that at about half way through the life of so called '1.5v' batteries they at 1.2v, possibly a bit lower.

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srnet

i'm going to use an Atmega328P and another arduino chip (Pro mini 3v3) to program the chip as a
Just about every '3.3V' Pro Mini I have used has the brown out reset voltage set at 2.7V, so you wont get a lot of battery life if your powering the Pro Mini direct from a pair of standard 1.2V alkalines.

It can work, but you do need to set the brown out voltage to 1.7V.
$50SAT is now Silent (but probably still running)
http://www.50dollarsat.info/
http://www.loratracker.uk/

jremington

#5
Mar 09, 2018, 12:39 am Last Edit: Mar 09, 2018, 02:14 am by jremington
Quote
standard 1.2V alkalines.
?

For all of their useful life, especially in low current regimes, AA alkalines produce 1.0 - 1.56V, and you can turn off the brown out reset completely. So 2xAA are in fact optimal for powering ATMega328s, which run at 1.8V.

100 mA discharge curve (at lower discharge rates, the curve is higher and flatter):

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