Power supply problem

Hi , I am using Arduino mega 2560 and have connected 3 sensors of 5volts input and 1 GSM sim900a 5v module and 1 20x4 LCD module. I want to know how much external power supply adapter with how much amp should I connect it to get all sensors working properly.

Thanks in advance

The best way is to try it with a "hefty" power supply and measure it with a multimeter.

Or you can look-up the current requirements for each module/component and add them up.

The specs for [u]this GSM shield[/u] say it can consume up to 2 Amps.

If I look at the power requirements all the sensors power when added up it makes up to 25-30 volts. Is that mean should supply power supply of 30volts.

No, volts don't add. Amps add. Your various devices work off a specified voltage, all of them 5 volts. So you should have a 5 volt power supply. Doug was suggesting that you hook everything up and then use an ammeter to determine how many amps your 5 volt power supply will need to supply. I find it best to get a power supply that can deliver at least 150% of the needed amps.

kirans: If I look at the power requirements all the sensors power when added up it makes up to 25-30 volts. Is that mean should supply power supply of 30volts.

Hmmm. Perhaps this electronics stuff is a little advanced for you! :roll_eyes: