bareduino vs arduino mini/nano

I'm in the process of making a bareduino to reduce power consumption. I'm still relatively new to arduino so I'm just following a tutorial to strip out some of the main components. (http://www.instructables.com/id/YABBAS-Yet-Another-Bare-Bones-Arduino-on-Stripb/) I did a search on ebay the other day and $3 arduino minis and nanos were showing up. Do these use the same power as an arduino uno or is there some power saving benefits as well as the size?

My real question is are there premade sripped back arduinos cheaply available? I know sparkfun and seeduino have low power arduinos for sale but they cost 5-10 times as much as the knock off minis and nanos. I'm hoping to build a couple of these so having a basic unit premade would save a lot of time and effort

Examples of what im looking at
http://www.ebay.com.au/itm/1PCX-Mini-Arduino-atmega328-5V-16M-ATmega128-For-Arduino-Compatible-Nano/191788955839?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20140106155344%26meid%3D12a34e493e344fec98cbeaa1d81c2c26%26pid%3D100005%26rk%3D4%26rkt%3D6%26sd%3D321953138455

http://www.ebay.com.au/itm/Useful-Device-for-Arduino-Nano-V3-0-with-ATMEGA328P-Module-Mini-Module-Board-BII-/262082646342?hash=item3d0557d146:g:5zkAAOSwoydWi6cZ

Sure, you can easily modify a mini.

I have build barebones, but now I use a Pro Mini. For battery operation I use a Pro Mini 8MHz 3.3V, and I remove the voltage regulator and the led and I power it with three AA batteries. Together with the Narcoleptic library, it runs for more than a year.
https://code.google.com/archive/p/narcoleptic/

If you get those ATMega328p it uses less power than those without the p.

I've done bare minimum, 8MHz internal and it runs on breadboard and other than vcc, ground, 0.1uF cap, and reset pin high nothing else is needed.

I used this Tutorial to get my 8MHz breadboard Atmega 328 working. It runs fine together with an nRF24 transceiver just from 2 AA batteries.

...R

If you want to further increase battery life, you can run a Barebones ATMEGA328P (crystal, 2 capacitors and a pull up resistor) at 4MHz, then you can set the brown out (failure) voltage to 1.8 volt via a fuse. If you stay at 8MHz, the brown out voltage should be 2.7 volts.

Great thanks for the help guys! I’ve now got more questions than I started with but that’s a good thing! Has anyone used the the stripped back ATMEGA328P with a GSM module? I was reading that the slower process speed may mean more power is used during energy intensive processes. I guess I’ll have to try it myself, but while connecting to the network the GSM shield uses a fair bit of power. I don’t believe the time this takes would be tied to the processing speed of the ATMEGA but it’s possible I guess.

FYI this will be used with a battery and a solar panel so small inefficiencies are acceptable. But I want to reduce the solar panel to the smallest size I can so people wont want to steal it which will mean I’ll need to reduce power consumption. I also have a few minis on the way because they seem quite disposable and easy to reduce the power on.

I suspect that if you are going to have enough power to run a GSM shield then its not really worth trying to squeeze the last mW out of the arduino side. I found that a 5V pro-mini running off 3 batteries used less than a mA in sleep mode once I removed the blue power LED.

What percentage of the time does the GSM device need to be powered up?

If it only sends a short message every hour or once per day its total energy consumption should be low even if it needs a lot of power to operate.

...R

since you are new, forget making your own. get the board you like, UNO / NANO / Mini / Micro and stip off the power hungry bits. now you have a form factor you can work with easily.

see Koepel's post #3