Which Arduino for small current during sleep mode

Projects General Guidance
1

Hi,

I'm pretty new to the world of arduino, but not AVR. I have worked on several projects so I should know at least the basics.

I am looking for an Arduino with a low power consumption during sleep mode. To be more precisely I want to power the Arduino from an 9 V battery for about 1-2 weeks. The arduino can sleep almost the whole time.

Can this be achieved with an arduino without greater changes of the design? Maybe an arduino pro?

Maybe you can share your experiences.

Best regards,
Mo3bius

2

Don't need USB connectivity?
Use 3 AA or AAA batteries, powering a Promini - bypass the regulator so you're not knocking 9V down to 5V the whole time.
Or maybe a standalone design with minimal parts.
http://www.crossroadsfencing.com/BobuinoRev17/

3

I don't want to design the whole thing on my own. Did this in the past, but this time I don't have the time for that.

I thought already about an pro mini. 3 AAA are meant for the 3.3 V version, right? Can I bypass the regulator with 3.6 V? (Rechargeable batteries)

4

3 AAA for 4.5V, no regulator needed.
8MHz or 16MHz will run on that voltage.
8 MHz will use less power, can run on 3.7V Lipo.
I have an RF remote control with 8 MHz Promini running direct from LiPo. Battery connection is to Vcc, after the regular (RAW).
Wakes up on keypress, sends the key info, goes back to power down sleep mode. Lasts a month or so between presses. Not pressed very often most of the time.
Didn't do anything special to save power on 434 MHz transmitter, besides not sending it data. Did not remover power LED from the promini.
Uses MAX1811 to control battery charging from 5V source.

(not shown in this picture, is mounted on a 8-pin DIP adapter, some Rs/Cs go next to the diode for it)

5

Thanks for that detailed explaination. I will go for the Arduino pro mini with 3.3 V.

One last question: Is the USB Serial Light Adapter (http://arduino.cc/en/Main/USBSerial) compatible with the pro mini? So can i solder 6 pins to it and plug it to the adapter?

Best regards,
Mo3bius

6

Mo3bius:
Thanks for that detailed explaination. I will go for the Arduino pro mini with 3.3 V.

One last question: Is the USB Serial Light Adapter (http://arduino.cc/en/Main/USBSerial) compatible with the pro mini? So can i solder 6 pins to it and plug it to the adapter?

Best regards,
Mo3bius

I'd look at the EMS Diavolino, the AFI DC Boarduino (leave the power LED off), or something similar. I'd almost certainly not use a 9V battery. Some recent current measurements I took are here.

7

You can also power the Nano from its 5V pin and the USB-serial chip automatically goes into a microamps-level low power mode if there's no USB signal. In PWR_DOWN sleep, the power LED will be drawing multiple times what the Atmega 328P will draw - it's worth removing it.

Nick Gammon has an excellent page on sleep modes and power use:

Ciao,
Lenny

8

Yes. Only need it attached for programming, yes?

9

Yes. Only need it attached for programming, yes?

Yes, just for programming. I just prefer some simple plug and "programm" instead of building something on my breadboard.