Quote Originally Posted by Ioannis View Post
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
but it's working, i put a hex inverter 74LS04 and inverted the signal two times, 1 x 2 times logical not give 1, and put one zener didode 2v7 in tx line of phone!!!!so it's protected from over voltage!!!