measure several devices voltage and current

Hi all,

I am a newbie in arduino. I have a idea to make a project to display a system status on a 3.2 LCD TFT screen but I would like to minimize necessary modules to be used. The system is like that,

12V DC input,
3 modules to 5V, one for the arduino, the other two are connect two USB ports,
a 12V DC fan (3pins or 4pins), the speed of the fan depends on the temperature of the system that read from arduino.

I want the 3.2 TFT screen to display the following information

  1. Date, time and temperature
  2. the voltage and current of main power supply (that is the 12V DC)
  3. the voltage of the two USB ports individually and current used by the devices (that is the voltage and current output from individual USB port)
  4. the voltage, current and RPM of the 12V DC fan.

The other information like alarm, warning messages I think I can handle, my main concern is what component and modules I should use. Does this project can completed by using only one arduino board? As it contains a 3.2 screen and about 6 sensor modules

Thanks

you need to work out what components you would use and their IO requirements
e.g. if you use a TFT display with an I2C interface you only require two signals SDA and SCl in addion to power
for date and time use a DS3231 RTC - again I2C so will use SDA and SCL
etc
a UNO would probably meet your requirements
Arduino Uno

could you give more details of the USB requirements? do you require USB host capability?

I think the USB ports will mostly for charging mobile phone, so USB host capability is not required. I have a 40pin touch screen and shield for mega on hand, but the mega is broken. A Mega or Uno I should buy to completed the project? As it is several sensors need to be connected, I wonder the 40pin display can use the shield or not, I found how to connect it by wire, or I should buy a Uno and a I2C display?