Writing values to an SD card (Leonardo)...

I'm pretty new to Arduino, but I was hoping to recreate this project with one adjustment, I want to write to outputs, the readings from the radar gun to an SD card, or something similar so I can create a standalone unit, and take the reading off the card late and paste them into a spreadsheet. I won't be able to connect it to a computer and let the readings output to the serial monitor as the project exists. I should add, I'm only doing the first part of the project, the phase one, reading radar speeds, I won't be creating the radar board. I'm just going to use the Leonardo board permanently. That means this is the code I'm trying to modify. I figure it can't be very hard in terms of the changes to the code. I have no idea how I would connect an SD card, would this work? How would I connect it?

Thanks for any help! I really appreciate it!

Most cheap SD modules use crappy voltage leveling that eventually ruins the SD cards, sorry to say (since I have 8 of those).

That one you linked to is not cheap price (tariff?) and looks like it might have voltage dividers but you should check.

There are DIY SD card readers that you can voltage level yourself -or- connect to a 3.3V board and connect directly (I can with those 8 I have, why I still have them) since SD cards are 3.3V devices.

You can start with a module and work with the SD library examples to ensure it is working and then move over to Kevins' code.

Kevin should learn about bits and the use of else. His code would be much smaller and faster.