There are two stages, one which converts RS-232 to TTL, and the other converts TTL to USB. [André] removed the RS-232 chip and patched his own board (shown on the left) into its TTL lines.

I think the point is you don’t need a TTL to RS232 for to talk to your 1.8-5V TTL device. Besides RS232 polarity is inverted c.f. TTL – 0v represents +V, 1.8-6V represents -V. Report comment ...