Power-saving question

hi all,

i use Arduino Uno connect to some sensor , these sensor power from arduino 5V pin when use external power supply, Duration is less than expected (Up to 6 hours),i hope can least one day What can help me? i know Arduino have "sleep mode", it is i need ?

thanks.

The Arduino does have a sleep mode, but I don't think that will prevent the sensor from drawing power from the 5v pin.

Even with a sleep mode the Arduino will draw quite a lot of power as the USB->serial chip will still be powered up. What is your power supply? What's the sensor? How long do you want it to run for?

Some Arduino powers have less components to consume power and can sleep at low power (Arduino Mini Pro perhaps).

power supply : i series connection two 3.7V 4000mAh , sensor : i use Humidity and Temperature Sensor , CO2 Sensor , SD Card shield i hope can Duration least 12 hour...

There are other ways to solve this problem ?

thanks.

Look at the individual current consumptions of each component to work out which are the worst offenders…

Perhaps you can power down some of them for most of the time?

SDcards can be very power hungry when being acessed I believe. CO2 sensors have a heater element I think - perhaps this is the main culprit?

4000mAh should give 250 to 300mA for 12 hours, which is a lot more than just the Arduino takes.