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 ?
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...