I wasn’t gonna do it, but I mentioned the cable wiggling at me in my review and I really wanted to like this dock even more. Xiaomi dock|battery|wireless (alternative US friendly link)charger (review) was a good, simple and yet flawed concept, now – it’s simply brilliant. All at the cost of 1h of your time and $2 in spare parts.
From not perfect
The biggest issue was the cable itself, mostly cause I appreciate taking the dock with me as well as the battery. I do not always have a place to plug in the dock, and having the phone docked is often more welcomed than having it flat on the table. I don’t usually carry a USB-A charger, but that was never an issue with the dock equipped with its own battery.
I already converted one of my gadgets to USB-C. It was my Lenovo Yoga 710 series. Encouraged by how easy it was to dupe the system in thinking it’s equipped in USB-C PD charging standard I was really keen to add a detachable USB-C option to my dock.
Turns out, it was really simple and inexpensive. Which in turn makes me wonder why Xiaomi didn’t do so. The original design uses the USB-A connector with Quick Charge 3.0. It can deliver up to 12V of power when the battery and the phone is being charged. The goal is to retain this ability while having a detachable USB-C cord.
4 pins, 5-pins: who cares – USB-C PD cares!
There are 4 screws hidden underneath the rubberised mat, that hold the dock in one piece. It’s easy to peel it off and open it without inflicting any damage. Inside, the USB cable is linked to a PCB with 5 pins. One of them (blue) isn’t really needed if your cable is going to be a USB-C, but if you want to take advantage of the USB-C PD chargers, you will need to connect 5 cables and add a pulldown 5.1 kΩ resistor.
I wasn’t sure what to do with this wire, but initial research online identifies this as a CC pin, which is important for USB-C PD specification. If you want the dock to work correctly with USB-C, you will have to do this as well. If you are happy with Quick Charge via USB-A only, you can leave it out unconnected.
If you watched my Livestream you will know that I missed that opportunity, as I initially thought 4 cables were enough, and as the USB-C slot was already soldered in, I could only salvage it by adding USB-C PD that works in a single orientation of the cable. Fortunately the for the USB-A to USB-C cables the orientation won’t matter. I wish I could find this page a little sooner which was a great source of information on that matter.
|USB cable||USB-C female connector|
|White||D- (B7 & A7)|
|Green||D+ (B6 & A6)|
|Blue||CC (A5 & B5) connected to GND via 5.1kΩ resistor|
This is the mapping I used to solder the cables to my connector. For reference, I will also include pictures of the general mapping for each connector. To make the connector reversible, you will have to add 2 more wires.
My USB-C socket already shares GND and VCC on both sides, so I don’t have to link these. I do however need to make small loops between A5:B5, A6:B6, A7:B7 to make the socket work regardless of how the cable is plugged in.
A little Dremel action was needed to widen the hole from the original cable and I was able to slot in the connector. Once soldering was done, I used epoxy to fix it in place, then a little wood filler to close the gaps around the new USB-C socket. At this point, I got super lazy and used a sharpie to blacken it as when the USB-C cable is plugged in, you can’t really see the modded area.
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I think Xiaomi should consult me from time to time, to make sure their products are more attractive! The dock has all the flexibility I need and none of the waggling tails of the past. Now my collection of modded USB-C ports into gadgets has a nice even number of 2. I’m pretty sure that’s not going to be the last one. I still strongly recommend this dock even if you are not going to mod it. But if you do, feel free to let me know in this Reddit thread.