I find it crazy that this doesn't work out of the box, but neither atftpd nor tftpd-hpa seem to have any way to log to the console. I've run them in the foreground with verbosity right up but clearly that's not the right magic incantation.
I'm running a short-lived server for a firmware upload and I want to see the requests (and ideally when they've completed).
Try something like this:
atftpd --logfile /dev/stdout --no-fork --verbose 3 --daemon /tftpboot