Standalone 'idiot proof' programming

We have a couple of Ethernet connected devices we have out in the field for testing (more our sensors being tested, but that’s another issue). We would love to be able to send ‘tweaks’ to the sketches running on these devices to their ‘owners’ (they are typically running in peoples homes, doing environment monitoring) to download to the devices using USB or a supplied FTDI cable. We would prefer not to send the source code and let them use the normal editor environment for several reasons - first of all its probably too ‘geek’ for many, and secondly it would expose some of the algorithms used and URLs called by these modules which may be an issue if someone wanted to be ‘silly’.

Is there such thing as a Windows command line download utility, something along the lines of “downloadsketch.exe com8 objectcode.file” that we could send them as a ZIP (explaining the COM selection possibly), that would let them plug in, update, and resite - much like a home router or similar??

Thanks in advance.

It’s the .hex files that load into the chip.

avrdude is the programmer.

So with a little google-fu, i can command line avrdude along with the hex file produced by the environment and use this to 'headless' program an Arduino ?

Thanks guys for your info.