I have completed a project that I thought could be adequately maintained by manually programming software updates as necessary by running around with a laptop and a conventional USB programmer, or PICSTIC. The handwriting is on the wall now, and I can see that the software updates are never going to end, and I'm going to be making field trips forever

I would like to add a piggyback USB programmer circuit to my circuit board that had a USB input and connected to the usual ICSP header. (The USB input would come from a linux based computer that is also included in the project, and network connected.) The linux pc part of the project was not mine, so the software would need to be fairly 'generic'. My question: Has anyone already done this and willing to share their circuit/software?

Best regards to the group.