Hi,
i don't see any discussion in this forum, or i missed something perhaps,
i already read some advise to pull up floating tx, and i did, but i get same result, even i add some 330 from v+ supply to max232 vcc, still no luck.
dirty power suply, i am not quite sure, i just use USB VCC, but maybe there is some chance this is the cause. i already plan to add external power suply recently, but i haven't done it
what do you mean by bad PCB layout? i know a few practice to design PCB. but if there is any reference you have regarding this problem i would be very happy