This USB to serial converter project is easy to build, it is simple and inexpensive. It is based on theFT230XS from FTDI Chip.
The FT230XS is outfitted in SSOP-16 packaging. The first incarnation of FT230X chips got a nasty bug when the chip inadvertently goes into suspend mode triggered by certain byte sequences.
The FT230X releases A, B and C were affected, see FTDI Chip TN_139 Technical Note. The resistor R1 connected to CBUS3 pin is providing a workaround, keeping the chip awake.
After assembling the converter run FTProg utility to configure CBUS3 pin as Keep-Awake#.
3D PCB rendering