hello. i have an arduino that will be used for the project. i am planning to power it up via usb.
my question is what power rating of the supply should i use? i have a 5v 2a adaptor and 5v 1a. can i use any of these? i am powering all the devices (lcd, rtc, and lots of logic gates) of the project.
5V, 1A means that power supply can "give" only 1A at 5V. But actual current depends on device being powered - if arduino is rated 300mA, it will only draw 300mA from power supply. In this case Voltage is the most important thing.