So the USB A accepts 5v 2A of power? Can you point me to where I can find a power supply that provides a USB-A connector?
(Is it me, or does it seem the power solutions for Khadas VIM were not fully thought through? Everything else about it is what we need…)
Hi, Mikeschinkel:
It seems that you confuse with with power supply for Khadas VIM:
USB-C is main power supply for VIM, what you needed is just a USB adapter for the USB-C cable
VIN is extra power supply
USB host is also a optional extra power input
My concern is my use case would need the OTG USB port connected to my customer’s computer, and most of those are going to be USB 2.0 (0.5A) for the near future. So I assume that will mean I must provide my users with a wall wart power adapter using your VIN extra power supply or your USB host optional extral power input. Yet I cannot find a wall wart with support for a VIN or for USB A cable.
Does my use-case and my needs not make sense?
A wall wart(DC adpater) with USB port would be works fine, just like this:
This DC adapter can work both for:
Ok, thanks, but how to find VIN to USB cable or male-to-male USB cable. I have looked for both and cannot find any.
THANK YOU! (I did look. Honestly!)
I continued looking and found these. Would you agree these would work as a power supply can cable I could package with a Khadas VIM to allow the USB OTG port to be available for the computer’s use?
1-Port 2.1A USB Wall Charger
https://www.monoprice.com/product?p_id=16072
1.5ft USB 2.0 A Male to A Male 28/24AWG Cable (Gold Plated)
https://www.monoprice.com/product?p_id=5441
I don’t doubt you, I had to use a few search terms before they popped up. 
It is important to note that the two USB ports have different mA ratings.
The USB port next to the USB-C port(the same end as the switches) has a 900mA max.
The USB port next to the LAN port is rated at 500mA max.
In either case, these are substantially less than the 2+ Amps available through the USB-C or Vin header.
This could be a factor if you plan on using the remaining USB port for accessories.
Yes, High-Amp USB chargers are almost ubiquitous these days.
The cable you linked is only 18 inches long. Is that long enough for you use?
I am aware that accessories connected to a USB A port can only draw 500mA, and that USB C can only draw 900mA max. However I am not skilled enough to read and understand the schematics which is partly why I have been pushing for off-the-shelf solutions.
Are you saying that if I connect a USB-C to a 5V2A power supply that it will not be able to provide 2A to the Khadas VIM? And that the same would be true if I were to connect power via VIN?
What about via the USB-A port? Can it draw 2A from a 5V2A power supply like the one I linked from Monoprice?
My use-case is as a headless server. I need one USB-OTG port to connect to my user’s laptop or desktop – and I expect to use the USB-C port for that – but I do not need the other two (2) USB-A ports so it one of them can support the full 2A of power then I believe the above links give me what I need (no?)
Thanks for asking that. The link provided has cables from 1.5ft all the way up to 15ft. We are considering offering our customers a choice of length (1.5ft vs. 3.0ft vs. 6.0ft) when we are in our “working prototype” phase and that will help us understand what most people would prefer, and if it makes sense to provide an option once we are in full production sales mode.
That said, we’d have to test the 6.0ft to see if it could provide enough power.
P.S. I usually want shorter cables and am always annoyed when I am supplied a 3ft cable for a 1.5ft need! FWIW. 
The USB ports are protected by fuses. You will note from the schematic, the fuses are 500mA and 900mA. Current traveling in or out of the USB ports must travel through these fuses. Current in excess of 500mA or 900mA will blow the fuses, respectively.
That being said, running headless and not using USB devices will reduce current demand of the Vim. What the Vim needs for operation, is yet unknown to me. I have to assume, as Gouwa suggested the 900mA USB port as an alternate power input, it can be adequate to run the Vim. But if it is adequate, you could only utilize about 1Amp(1000mA) of the 2A adapter in your link(when powering via USB). The 2+ Amps supplied to the Vim through the USB-C or the Vin header is in excess of the current needed to run the Vim, the excess is provided to supply connected USB accessories power and/or the GPIO. So we know 2A is not required to run the Vim.
The USB-C port is good for 2A.[quote=“RDFTKV, post:17, topic:146”]
… 2+ Amps available through the USB-C or Vin header.
[/quote]
Yes, I don’t care for “too long for their purpose” cables either. However, better too long than too short. 
I have been going based on assumptions that the Raspberry Pi 3 needs about ~1500mA at peek that this unit would need more than 900mA. If that is the case then it would seem the Khadas VIM could not be powered by only one power input, no?
BTW, thank you for all your help!
As I understand it, both the Vin header and the USB-C port can handle 2A. I think they share a 2600mA fuse.
When using Amlogic USB Burning Tool to install an update on AML devices, I disconnect the box’s power supply. When the tool fails to recognize the box, the box goes on to boot, powered only through the PC’s USB port. I was using an old Windows slate to burn a box one day. I had set the tool to reset the device after burn. When the burn was done, the box rebooted. I forgot to reconnect the power supply to the box and played with it for at least an hour before I realized it was running from the PC’s USB port. During that hour I tested Kodi on 4K content, played Asphalt 8 Airborne and other high-load apps. The box seem to have no trouble running from the PC port’s available 500mA.
These devices are amazingly efficient.
Hmm, low power requirements would be good.
Where I think we are likely to max the requirements if if our customers (accidentally) program an infinite loop and cause the PHP process and web server to take up the whole CPU, or if they run a MySQL query that takes a really long time to run.
What do you use the Khadas VIM for? Personal use or to sell as a product?
Learning aid. 
Yes, just personal use, i.e. learning and fun.
BTW I do not have a USB port voltage/current tester, or we could find out what max current draw is. While I have a multimeter, I would need to make a breakout to test for current. I keep meaning to order one of the little port testers, but keep forgetting.
Looks like something in my future. Thanks.
I like the little MantisTek, but it is more expensive. It is a nice little unit according to a friend.
But any would do.
Okay, so I have tried and the VIM now will not boot to Android or Linux.
I am on Mac so I had to use xz to extract rather than xd.
I am trying to run Armbian_5.24_Amlogic-s905x_Ubuntu_xenial_3.14.29_20170118.img since I want headless.
I had to change bs=4M to bs=4m for dd command and of=/dev/disk6s1 for disk after running diskutil list to identify my disk.
When I ran umount /dev/disk6 it said umount: /dev/disk6: not currently mounted so I ignored this.
Instead of sudo mkfs.vfat /dev/sdb1 I had to run sudo diskutil eraseDisk FAt32 KHADASVIM /dev/disk6
Instead of sudo eject /dev/sdb I clicked to eject from inside Finder UI.
I ereased EMMC using Key Mode although I am not sure about U-Boot running since I do not understand that.
Then I inserted card into Khadas VIM and connected USB-C port. Nothing; my TV sees no HDMI signal.
Help?
I am wondering if I should be running a different command that umount? Also, do I understand that we dd the image BEFORE we format FAT32?
