How improve electric consumption ?(watchdog and sleep mode)

Hi,

I'm building a weather station and I would like to imrpove my electric consumption.

Configuration: Arduino UNO SMD rev2 + Shield SD Sparkfun + SHT15 (Temp & Hygro )+ MLP115A1 (pressure) + 9V battery

In summary, I need to manage one measurment per minute. I would like to sleep the board during 55mn and wake up 5mn before a measurment, just to heat correctly the sensors. I know that, there are 6 kind of sleep modes, but, I refused to use an external counter.

I'm a recent user of Arduino and I need a lesson about this using...

I don't know exactly what sleep's level I can hope with a internal counter. I thought use the watchdog, I'm currently trying to understand how use it...
In a second time, I thought during my 5mn of heating make a choice to shutdown some board's compoments with this kind of command: power_timer0_disable();
power_timer1_disable();
power_timer2_disable();
power_twi_disable();
...
but I don't know if it's available...

Is there someone to teach me???

a) It won't make much difference - by far the biggest consumers will be the voltage regulator dropping 9V down to 5V and the other support chips on the board.

b) 9V batteries have a really bad power:size ratio. If you really want it to run for a long time get a holder for some D-cells and use those instead.

Get a Seeeduino Stalker, it's optimized for low power usage (DC/DC converter instead of linear voltage regulator, 3V3 8Mhz) and includes a battery backed RTC that is able to wake the ATmega at alarm time. It also includes a LiPo battery controller and solar connector. Ideal for your usage I think.

If you want low power consumption, you'l need to use a board without the USB-to-serial converter, or build a barebones Arduino board. Consider running it at a lower frequency to save power (I normally run battery-powered projects at 8MHz). If you want to run it from a 9V battery because you need a stable 5V ADC reference, use a micropower regulator such as MCP1702. If you don't need a stable 5V reference, run it from 2 or 3 AA cells instead for better battery life.

There are lots of sleep modes available, some of which allow you to continue running the clock and one or more timers, so you can get an interrupt at a precise interval to wake up the mcu. If you use the watchdog instead then you can stop the clock to save power, but the wakeup interval will be less precise.

I need to manage one measurment per minute. I would like to sleep the board during 55mn and wake up 5mn before a measurment

What is "mn"? A second?

Low power consumption is discussed at length here:

As the others above have said, you first have to ditch the Uno board because of all the power it consumes even if asleep. Use it for development, certainly. But then get a "bare bones" board (for around $10) and use that in production.