Core with LiPo Charger connection issue

[BDub]

@Bendrix

This charger is designed as a backpack. It is soldered to the uP board, such as a Pro Trinket, and then when the uP is connected to USB the LiPo charges. When the USB is removed, the LiPo takes over powering the uP. Very slick and something that would be a good option for Photon and Electron.

@Bendrix I would love to be able to just solder on the Adafruit Lipo backpack, but as you can see from the referenced thread we talked about this before and the way that works with the Trinket so well is that it has a Diode-OR'd power source. The Core does not, which is why I have proposed the external diode:

SparkCore with LiPo Charger

I am trying to power the SparkCore with a LiPo battery and I am trying to use a single USB port that would allow for charging the LiPo as well as connect to the SparkCore. As an example, Adafruit has a LiPo charger backpack for it’s Trinket (https://www.adafruit.com/products/2124) that connects to a battery input pin (which would be Vin on the SparkCore), a ground pin (Gnd, obviously), and a “Bus” pin, which allows for the 5V from the USB to go directly to the charging circuit. Is there a way to…