The Hserout/Hserin will NOT work with these circuits! Be careful also not to destroy your phone with this 3.3/5 volt adapters. I would suggest to test with the Serout2/Serin2 commands in invert mode.

Hserout/Hserin pressume that you have included inverters in your circuit (like the common MAX232, which obviously there are not).

I would use a 3.3 driver for the UART like MAX3232 for example.

Ioannis