[Samsung Galaxy S9+ Accessories] cookiemonster79:
I recently purchased a Goodock USB-C to HDMI adapter. The package just included the adapter itself with no brand specific logo on the package or device. The adapter has a USB-C plug/cable (for connecting to your phone), a HDMI port, a USB-A port and a USB-C port (for connecting power to the adapter which also charges the phone).

The adapter is marketed for specific devices such as the Nintendo Switch, Samsung Galaxy S8/S8 Plus/Note 8, Macbook, ChromeBook, Dex Station. The part that really caught my attention is the adapter was marketed as being able to put the Samsung S8/Note 8 into the DeX mode in addition to the normal screen mirroring of most HDMI adapters support.

As soon as I got the adapter, I started to play around with it. I had a Samsung S9 Plus, a HDMI to VGA adapter, USB-C power supply and a Dell computer monitor that I used for my test setup.

Based on my initial tests here is what I noticed:

1) If you connect the adapter to the phone, but do not connect a USB-C power to the USB-C to HDMI adapter, it seems to only work in mirror mode.

2) Once you connect power to the USB-C to HDMI adapter, it goes into DeX mode.

3) If you do not connect a USB mouse, the phone screen will turn into a pad that you can use to control the mouse. Once you connect a mouse, the screen just goes dark. For my test setup, I used a USB keyboard (that has two built-in USB ports) and a wireless mouse (receiver plugged into the ports of the USB keyboard).

4) There were a few random disconnects but they were very quick. I am not 100% sure I can blame it on the USB-C to HDMI adapter, since I also have a HDMI > VGA adapter in my setup, but I never had this issue using the same HDMI > VGA adapter with my Raspberry Pi so it was probably the USB-C to HDMI adapter.

The DeX mode is pretty cool. I am not going to go into all the expected features, because you can probably find other websites / reviews with details or just read the Samsung info ( http://www.samsung.com/global/galaxy/apps/samsung-dex/ ). I will share a few high level things I noticed so far using DeX:

Some of the applications seem to open in a window that basically looks like it would on your phone, but others (such as Chrome) allow you to resize the window. Using Chrome on DeX was very similar to using Chrome on a computer. I also liked the fact you can have multiple windows open - for example Chrome and another application. Using Google Play Movies, I was able to put a movie on full screen. I did run into a few application that would not run at all, but none were apps I felt that I would have missed - and of course they are still usable on the phone when you leave DeX mode.

While you are in DeX mode, the device is still works as a phone. I was able to receive and send text messages, and answered a test call just fine. If most of your computer apps are web based or available in Android, I think DeX is a great way to leverage the power of your existing smartphone. I wrote this blog post in DeX mode, and really after using it for a while you just feel like it is a normal computer.

At the end of the day, I don't know if I will find DeX mode to be useful or just a neat gimmick but either way the Goodock adapter is much cheaper than the official Samsung options and is a great way to play around with the capability. Even if you don't like DeX mode, the adapter supports screen mirroring.

Bottom line: If you are interested in playing with DeX mode, then this Goodock adapter is a great low cost option. Just keep in mind, you may see random disconnects.

Amazon Product Page: https://www.amazon.com/gp/aw/d/B074ZP5Q51