I found a bug of NON OS SDK 2.2.
It can only connect to wifi network with visible SSID and can't connect to hidden one.
I tested the same code on SDK 2.1 without any issue.

Regards,
Simon

在用基于ESP8266 的ESP-12E设计电路，结果板子出现一个问题，用电池工作正常，但是当给电池充电的时候会有很大几率出现唤醒时Boot失败，出现exception(0)。
后来发现手接近天线部分后，唤醒就没问题了，如果在天线下面垫一块电路板，也可以正常。很是怪异

Dear,
Is there a serial number or unique ID in the chip for me to identify the chip?

Thanks