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Comment by AceJohnny2 | Hacker News Reader

I wish there was a consumer-accessible tool that I could plug a USB-C cable in and it could tell me its capabilities. (I remember in the not-so-early days when Benson Leung, a Google Chromebook engineer, would on his own time buy and test cables on amazon and rate them. Some were actually dangerous and could fry your equipment!)

Is it a "charge-only" cable that can only do USB2 speeds? How much power can it transport (if there's no id chip in the cable, perhaps this can be deduced by measuring the voltage droop when requesting various power modes over USB-PD)? Can it carry DisplayPort-over-Alternate Mode? -over-Thunderbolt? etc.

Last I checked, 6 months ago, it seemed there was only lab-scale equipment that could do this.

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I dealt with USB-C hell when I was setting up my new office. BYO (choose your own) laptops meant that the USB-C ports on each employee's laptop had different capabilities (alt mode for DP 2-lanes? 4-lanes? HDMI? etc...) and the same for monitors and docks. I got about half way through designing this device (PCBs went out, firmware never written), intending it mostly for identifying sources and sinks before I had largely solved the office's problems and my needs faded.

If there's collective interest, I could get back at it to finish the job.

There are already type-c testers that can monitor and dump the PD communication, so you can look at PDOs and Alt-DP VDOs to see what each side supports and what is negotiated. No need to re-invent the wheel.

As (according to the article) all of these cables carry little chips broadcasting the standards they support – couldn't this be just some little software app which just reads out that cable info?

The article is actually wrong on that point: many USB-C cables do not have any chip, only the ones which have extra capabilities (like being able to carry 5A of current instead of only 3A) need to have a chip.

I think you misread the article. It consistent refers to the connector on the cables as "cable end", and the places you plug these cable ends into as "ports". It says that the ports are the ones that broadcast the capabilities.

Tangentially, I've had great mileage out of the Satechi USB-C power-meter [1], which has demonstrated how cheap Amazon usb-c cables really don't carry as much power as Apple's expensive ones

[1] Out of stock, but I'm sure there are others on the market: https://www.amazon.com/Satechi-USB-C-Power-Tester-Multimeter...

Similarly I like my Witrn Qway U2 which does power meter but also gives you the ability to check which fast charge protocols are supported, and for USB-PD and QC3.0, the supported voltages and watts. You can even trigger them manually though I've broken some devices with this before.

I was going to recommend this too! It feels high quality and has a nice, bright display as well.

Linus media group will in the near future

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