MiFi external USB 2.0 power

Technical Support for Routers
1

Hi, I just noticed that if the external USB port is not drawing enough power from the port it powers down after a few seconds.

I had to use a USB hub and connect some dummy load to use the flash drive without the port powering off. Is there a fault with the unit or is that by design? Is there anyway around it?

Thanks

2

USB port should provide enough power for flash drive.

But you have to notice that when charging the USB power cut off. This is a known issue.

3

Hi @alzhao I think the issue is that the flash drive uses too little current and MiFi cuts off the power to the USB port after a few seconds.

I have to connect a USB hub with a USB network adapter to keep the port powered since it draws more current.

And the device is not being charged.

4

MiFi should now cut the power to the USB port. However I don’t know why this happen in your side.

5

@alzhao Is there any GPIO for USB power for that port?

6

@alzhao I have open the case and looked at the PCB and the version I have is v2.1.

7

Yes. There is USB power control. In the newest firmware, it has been mapped to LED, you can find out

ls /sys/class/leds/*:usbpow

For Mifi, it should be 0, setting to 1 will cut the power.

8

@alzhao

I am running LEDE trunk on a mifi, can you tell me what the raw gpio is so i can turn the USB port on while the mifi is plugged in?

Also, why would you stop power going to the USB port while the mifi is plugged in? Is there no way to tell when the battery is full to reconnect the USB power?

Acea