When sending a lot of data to an Arduino MEGA from a PC, the USB->serial chip seems to restart itself.
It goes fine up to about 8k of data, at that time when doing the Win32 WriteFile side, I get a 'ERROR_SEM_TIMEOUT' and the TX line of the USB->Serial chip becomes DC 5V with some weird glitching now and then...
After a second or 5 it seems to restart itself only to trip up again after again about 8k of data.
Found something similar here, and they seemed to suggest using an Arduino with a FTDI chip instead...
I also have an Arduino clone here with a CH340 chip, and that one works fine.
Any idea what I might be doing wrong?