My project uses the following: 1.) A NXP MK24FN1M0VLL12 based board. 2.) Kinetis Design Studio IDE v3.2 and Kinetis Software Development Kit (SDK2.0MK24FN1M0xxx12) 3.) FreeRTOS v8.2.3

My board doesn't have an ethernet port so I am limited to transfering files to/from the FreeRTOS FAT filesystem via a serial console. I've searched both the NXP forums and the FreeRTOS forum and other places on the best way to do this without finding much on the topic. To date, the best option I've found is to port the Zmodem protocol code lrzsz-0.12.20 from https://ohse.de/uwe/software/lrzsz.html. This looks like a somewhat painful approach to solving my file transfer problem. Does anyone know of a better approach to transferring files? Much thanks in advance, Peter

Its a long time since I've done something like that, but as I recall there were a few basic protocols around. You mention zmodem already, but also xmodem (don't remember what the difference is). You only really need to use one of those protocols if you don't control the software that is sending though. For example, if you are using an off-the-shelf terminal to send the file then you will have to comply with whatever protocol the terminal uses whereas if you are writing the software that sends the file you can use whatever protocol you like.