05-06-2020, 11:23 PM
Looking for advice on a quirk of the A64 LTS I have observed, using a LiPo battery as the power source.
When the Pine is shut down, the voltage on the USB hub (and 5V pins on the headers) drops to the battery voltage, between 3.6 to 4.2 volts, not zero as I would expect.
This is a problem for my application, so I have added a high-side MOSFET switch to save power (when shut down) and reduce the chances of damage to my USB peripherals (from low voltage).
So I'm wondering if there is a way in software/firmware to control this behavior, and if this is a bug or a feature? I've seen it on two from two LTS boards so far.
When the Pine is shut down, the voltage on the USB hub (and 5V pins on the headers) drops to the battery voltage, between 3.6 to 4.2 volts, not zero as I would expect.
This is a problem for my application, so I have added a high-side MOSFET switch to save power (when shut down) and reduce the chances of damage to my USB peripherals (from low voltage).
So I'm wondering if there is a way in software/firmware to control this behavior, and if this is a bug or a feature? I've seen it on two from two LTS boards so far.