Powering Conflict

Hi All. I’m considering using ESP8266 Thing - Dev Board for next project (WRL-13711, schematic attached):

https://www.sparkfun.com/products/13711

I want to power the project with external (wall wart) 5V connected to the VIN node. I’m a little concerned about what might happen with both external 5V applied and USB connected for firmware download and debugging.

If VIN is greater than USBVCC, then no problem as diode D1 will be reversed biased. But, if VIN is lower (or worse – turned off and presenting a low impedance to ground), then a large current might be drawn from the computer’s USB port.

I’m thinking the solution is to remove D1 from the board and require wall wart power even when USB is connected to computer.

Thoughts?

Thanks.

Greg