I have an ARM computer with an USB 2.0 OTG port, and I want to use it as 5V 100mA power supply (to drive a couple of leds). However, when I connect a load (LED+resistor) via an OTG cable, the power is not supplied constantly. The LED blinks shortly 4 or 5 times, and then shuts down until I replug the OTG cable. Additionally,
dmesg command reports:
musb-hdrc: configured as A device timeout
I suppose that means the OTG host supplied the power for a short time, but could not detect a USB slave on the bus and powered off the connector.
What does it take to trick the OTG host controller to believe there is a connected slave, so it keeps supplying power? Is this possible to achieve with a simple schematic, or is it absolutely necessary to implement the USB protocol? Is there a chip with low power consumption I could use for this?