esp8266 problem

[zogg44]

I recently bought one of the esp8266 modules shown on this site. When I power it up the blue led lights twice and then nothing else, and the USB connection continually connects and disconnects from my PC. I've tried it on another PC and got the same result.

What is the expected power up behavior for this module? Any suggestions on why it's continually recycling the connection?

[Yveaux]

@zogg44 did you install the drivers as suggested on the MySensors build pages?
The serial interface is able to reset the module, so a failing driver/USB connection might theoretically cause the board to reset.

[zogg44]

Yes, I did follow all the steps listed including the latest 210x drivers.

I found a mention elsewhere to connect up a second UART, so I did that and connected it's 5V line to Vin on the esp8266. After doing this, the module no longer disconnects/reconnects and seems to be stable. So for some reason there is a power issue with my cable or board, which I'll explore.

[Yveaux]

@zogg44 5v is way above the maximum allowed supply power of the ESP!
Don't be surprised if it stops working...

[zogg44]

I'm connecting to Vin on the NodeMCU board, not the esp8266 directly. Since the board is powered from a USB port, I assumed (maybe incorrectly) that Vin would also connect to the input of the voltage regulator that outputs 3.3V and/or whatever voltage the esp8266 uses.

I just felt the components and nothing feels hot. But also the module is unusable unless I power it up like this.

[zogg44]

Okay, it appears to be working now as advertised with only power from the USB connector, but I believe that the board has an intermittent connection on it. I can't see any solder joints that look suspect, so most likely it's one of the esp8266 pins.I will just have to handle it delicately. Thanks for the help.