Thank you for your suggestion. What is weak is 5V power supply. In fact on my board i have also dropped ftdi chip, and i connect to PC using a cheap usb to ttl converter from DX ( www.dx.com
- sku (p/n) 152317 or 224704). Both are already tested and communicate well, but the 5V is a little weak, considering than between 5V and 3.3V voltage regulator (an excellent L1117 from ST, 800 mA capable) i have inserted a protection diode. With stronger PwS Wi-Fi starts well.