I have a problem with the build in battery charger. My boron is connected to a main board. From the main board i receive over UART data packages. There are additional 5V and GND connections between them. On the 5V line is a diode, to make sure the main board can’t draw current from the battery which is connected to the boron. The problem now is, that after the diode only 4.2V are applied on the VUSB pin, which is not enough for the battery charger to charge the battery.
In the boron datasheet I couldn’t find a voltage range the charger at least needs?
Second question is, if I add a voltage divider after the 5V line to get 3.3V can I use this as an wakeup interrupt? So as soon as the main board get’s turned on, my particle will wake up to send the newest data?
Thanks in advanced.