I just received my hAP ax Lite (LTE version, but that probably doesn’t matter) and I discovered it can’t be powered by any native usb-c source (that is a charger with permanently attached usb-c cable, or any usb-c port with usb-c to usb-c cable).
I did read somewhere that it does not support Power Delivery (which is fine, it doesn’t need anything more than 5V) but that doesn’t really mean it doesn’t support USB-C power at all.
For proper power delivery using usb-c to usb-c cable you only need few resistors to indicate to the power source that this is “dumb” device only needing 5V, so it can enable the power to it. Unfortunately, looks like those resistors are missing.
It would be great to inform about that properly on the product page. Indicating that Power Delivery isn’t supported is not really enough, as that will be misunderstood by some people (Power Delivery is the protocol for controlling the voltage, “requesting” 5V using few simple resistors is outside of that spec really…).
Also my question: is there any planned revision of this router that would not have this issue? It is adding 2 resistors (if I’m correct that should be two 5.1k resistors, one for each CC pin on the usb-c port, while the other side of the resistor should be connected to the ground)
You can use regular USB-A type 5V chargers and USB-A to USB-C cable to power it. If the source is USB-C it usually negotiates the needed Voltage and hAP does not support that.
The point the OP is making is slightly different - besides and before negotiating Power Delivery - which is about higher than 5 Volts, and needs a “smart” chip, there is in the specs a provision to allow - still at 5 V only - to deliver more than the standard 500 mA, up to 3 A.
This is done through two 5.1 kOhm pull down resistors, nothing complex.
It seems to me a reasonable suggestion/feature requests as it does not change in any way the current operation mode of the device and would probably add 0.01 Euro (I am just throwing in a number, in any case very, very small) cost in factory.
On the other hand, I believe that people needing to not use the Mikrotik power supply (5V 2.4 A) very likely know how to do that.
I have difficulties in imagining common situations where a final user would want to power the ax lite differently, maybe the only one would be using PoE with one of those 5V ethernet splitters with step down converters, though it has to be tested if they are actually USB-C compliant or they - just like most USB A power supplies they just give whatever Amperes the device draws, I have seen two kinds of them, one with directly a USB-C male that - maybe - is USB C compliant and another one with a 5.5/2.1 female and a short jack/USB-C cable that surely is “everything goes” (and I have seen at least one with 5V 4A, which definitely exceeds any USB C provision).
Unfortunately, this footprint doesn’t match the USB-C port used in hAP ax Lite. From what I’ve seen, hAP ax Lite uses USB-C port with 6 evenly spaced pins, outer ones for GND, then 5V slightly inner, and 2 CC pins in the middle. DIYing shouldn’t be hard though, as the only pins exposed on this port are the pins we actually need.
The (stupid) USB C connector size is so small that soldering the two SMD resistors can hardly be defined an easy DIY job.
Moreover on a new device it would IMHO make little sense to void the warranty.
Personally if I had that need, I would rather use an external solution using (improperly or illegally) a couple of adapters/break out boards.
Still only for the record It seems that exists (available in India only?) an adapters combo that might do without needing to tinker with soldering: https://www.ultraprolink.com/products/usb-c-3-1-male-to-usb-a-3-0-female-otg-adapter-usb-a-2-0-male-to-usb-c-female-adapter-set-with-hand-straps
It is a design fault, and easy enough to make when you are not familiar with all of the complexities of USB-C.
The original Raspberry Pi 4 had a similar problem, although that was caused due to the two CC pins being wired together to a single resistor as described in this in-depth article https://hackaday.com/2019/07/16/exploring-the-raspberry-pi-4-usb-c-issue-in-depth/, and resolved with a small modification to subsequent production runs.
And as said before, the issue is that the Ax lite uses a USB-C connector but it is “dumb”:
It won’t negotiate (the Power Delivery protocol that allows negotiation of various voltages), nor it uses the “passive” setup needed to get more than 500/900 mA (up to 3A are possible with two resistors).
A USB-C compliant power source will simply not be able to output that amount of current.
A “custom” adapter or cable can be made, you need a female USB-C breakout board with the mentioned resistors and a USB-C male (also boards that can do the whole power delivery negotiation exist, they are called “trigger” or “decoy” or “spoof”).
I fixed the issue by performing a simple modification to the router:
Those 2 resistors are enough for the device to be 100% usb-c compliant regarding the power delivery mode. They inform the charger that connected device simply wants 5V (other voltages require active circuit that will “talk” to the charger to negotiate available options). Those resistors should clearly be included on the PCB, so the router can actually be usb-c compliant and compatible with any usb-c power source. They’re just connecting 2 middle pins of the used usb-c socket (that are representing CC1 and CC2 on the usb-c plug) through 5.1kΩ resistance to the ground.
