How can I check the time a cell was edited and set the time and date in other cells? Google script

Question

I have spreadsheet and I'm basically going to use it for inventory tracking and management.

1. In one sheet I'll have an app on my phone fill a list when it reads a QR code.
2. In the second sheet there is also a list with the specific QR codes of each item.

I need to know when a cell in the first sheet has been updated and put that information in the following two cells.

I'm using this trigger to check if ANY cell in the document has been updated.

function cellEditTrigger()

{
  ScriptApp.newTrigger('coolFunction').forSpreadsheet('awsomeSpreadsheetID').onEdit().create();
}

It works fine and it runs the 'coolFunction' function. However I can't seem to be able to get the time and date for the cells that have been edited and put that information in the next two cells.

I know I could use onEdit(e), but I still can't get the information from e.range and I would like my script to not have to be bound to the Spreadsheet.

Is there any way to accomplish this?