SD Card Logging For Our Boat Speedo. Part 5

Last summer we spent 6 weeks on our boat, "Bonny Mary". Surprisingly for a boat that moves so slowly, we found on several occasions, we needed to know how fast we were going.
Let's design a simple and easy to read, GPS based, speedometer for our boat - and any other application where we need to measure relatively low speeds.
We're going to use GPS positioning to measure speed so while we're at it, lets record a log of our position on an SD card. We're using an SD card as they are a cheap (and hopefully easy) way of implementing a large amount of non volatile storage.
We've got a cheap SD card module so let's see if we can connect it up to our Nucleo board and use the FatFS middleware to read and write files.
The tutorial I ended up using can be found at: 01001000.xyz/2...
The two source files you will need can be downloaded from: github.com/kiw... & github.com/kiw...
The FatFs documentation can be found at: elm-chan.org/fs...