Well loads apparently. if you're a propeller head like me, you'll l like this YouTube video:
Huawei P20 Lite USB OTG (USB On The Go) USB Host
This guy plugs in a USB CD, Hard disk, game controller and on and on... You can't fail to be impressed.
I just bought a cheapy
USB Type C to Type C, Type A, HDMI, Ethernet adaptor from fleaBay which looks like the attached pic. I think it does everything I want, but I'm not sure if you can reverse charge the phone from one of the USB ports, so I'll post up when I find out.
The HDMI looks great. I'm doing some microscope photography with my P20 Pro. Trying to get accurate focus on such a small phone screen is difficult, so hopefully I can plug it into my 24" LCD monitor and it will be easier.
The other thing I wanted to do was see who my phone is phoning. Or in other words, what Internet connections are being made. I noticed it's contacting Deutsche Telekom even though I haven't signed up for the Huawei cloud, or any cloud driven app. I think it's Hicare but we'll see.
I'm going to set up a Man in the Middle monitor with Wireshark, get the phone to talk to my laptop through the Ethernet port, bridge this over the the wifi connection for the Internet and monitor the Ethernet activity with Wireshark
I know, I know I probably should get out more lol.
Any road up, I'm waiting for the adaptor so will post more up when it arrives.
In the mean time, it would be good to hear from others that have got USB devices working on the OTG and this could be a bit of a list of working items.