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> The watch is simply missing the two 5.1k resistors connecting the CC1 and CC2 pins of the USB-C connector to ground that are required to indicate to whatever is plugged in that it wants 5v power.

This is so annoying. Back when USB-C was less prevalent, I bought a pair of wireless earbuds over another for the same reason as the title - because it used USB-C. But then I cannot charge it with my macbook, unless I add a USB-C to USB-A adapter.





This problem seems prevalent on cheaper devices. When I buy a device and discover it has this problem I always return it. I've seen it on the Hypervolt Go 2 (which I returned and replaced with a Theragun Mini) and on the Hitachi Magic Wand Micro (which I replaced with a Dame Dip).

Like the post mentions, I think this happens because the devices are missing two resistors that are needed to indicate, when connected via a USB-C to USB-C cable to a charging brick, that the device wants 5V power. Resistors are cheap and I think the only reason they get dropped is carelessness.

The whole point of USB-C is that you can charge any device with any power supply.


> This problem seems prevalent on cheaper devices.

I’ve seen it on plenty of higher-end devices as well; and even worse.

The worst offender I’ve encountered is the TermoWorks Billows. ThermoWorks is a well established brand that makes high end thermometers and is considered one of the best on the market. So I was quite surprised to discover how their ‘Billows’ product is powered.

The device itself needs 12v and has a USB-C port for power. You’d think it would do USB-PD to negotiate it’s power needs so you can just use any old USB-C adapter. Not the case. It comes with a USB-A to USB-C cable and requires a special adapter with a USB-A port on it that puts 12v on the pins that normally supply 5v.

I have no idea how they came up with this abomination. Why even use USB-A connectors if it’s not going to work with a standard USB-A adapter, and why supply an adapter that’s basically going to kill most USB-A devices you plug into it? If you have a custom adapter anyway, why not just use a simple barrel connector? Why put a USB=C port on the device if it can’t use USB-PD?

I can imagine some Chinese ali-express product using such an abomination to save a few cents on components, but why would a well-respected brand like ThermoWorks ship such a thing? It boggles the mind.


So it's based on Qualcomm Quick Charge? QC is a competing, slightly older, slightly simpler standard to USB-PD that can do what you described. It's...useful sometimes.

No, it’s not based on anything. A QC charger will output 5v by default and only increase the voltage after a negotiation. This is exactly as described: a USB-A style charger brick only it outputs 12v instead of 5v, no negotiation, nothing preventing you from plugging in a device expecting 5v and getting 12v. The only ‘safety feature’ is that it has ‘12V’ printed on it.

You can find it here: https://www.thermoworks.com/12volt-ac-adapter/


ThermoWorks products are made in China

and marketed to gullible Americans.


> ThermoWorks products are made in China

Not sure what you are trying to imply here. Products manufactured in China are of poor quality? iPhones are made in China and it would be a challenge to find any device with higher build quality than that. On the flip side, we all know how terrible the quality of US made cars is.


There are high-end brands that spec products to a high standard and have them made (to that standard) in China. But I agree, GP is confusing high-price with high-end.

That said, thermometry is pretty easy and well understood and you don't need crazy accuracy for cooking, so 'low-end' is fine really, just don't pay high-price for it.


The year is 2025 not 1985. If you pay them the Chinese can make you anything you want.

The thing is that there are lot of dollar stores in the West that want cheap shit for the paupers. And that is were the bad reputation comes from.


Yes, not sure if you meant that to be disagreeing, but I completely agree. China has is at par with if not surpassing the most advanced manufacturing capability of anywhere else in many areas. It can just also offer very cheap poor tolerance mass produced crap.

This happens because these devices had USB microB before and the manufacturer just replaced the port without reading the spec.

Even some mainstream products have this issue. I have an automatic door opener from a large company and the battery pack has the same issue. It is shipped with a special cable you have to use as no other USB-C cable works.



There is also another problem. The spec is large and it's not aimed at those who want to implement the simplest possible USB C compliant device.

Based on the table of contents the most promising section is "2.3.4 USB Type-C VBUS Current Detection and Usage" but it doesn't actually talk about anything you actually need. You're supposed to click through to the section "4.6.2.1 USB Type-C Current" where it shows the reference circuit, but it doesn't tell you the values of Rd, which are in section "4.11.1 Termination Parameters".

It's a 300+ page document where you must already know what you're looking for. If you didn't already know that you need two resistors, you wouldn't be able to figure it out with the spec alone.


Sounds like an "annotated spec" or some guides for implementers would be really useful.

When you use a well-documented chip, the datasheet will contain diagrams and they'll have a working demo board which they'll give you the full schematic for. Closer to 3 pages than 300.

Of course, a person can still get it wrong...


This is insanely common.

I have about 6 devices with this problem, and I consider it unforgivable.

Not only did you not include USBC charging, you went out of your way to trick me and lie and pretend you did. I would have preferred just using micro usb at that point.

Powkiddy committed fraud and said the RGB30 can charge from USB-C, but they lied, it can only charge from USB A to C cables. Using it is a massive pain because I have to get adapters I shouldn't need. I'll never buy anything from them ever again.


> I have about 6 devices with this problem, and I consider it unforgivable.

If you still have them, you've forgiven it.

Return them and complain about it, or the manufacturers have no way to tell it bothers you.


The RGB10 Max 3 Pro has the same issue, kinda annoyed with that since my new battery pack is USB-C only..

I feel like the USB committee might be somewhat to blame. When most people think USB-C they're just thinking the cable. Why can't it just do regular slow charging with C to C cable?

It can, it just needs the two resistors, which is the cheapest possible thing the standards committee could have asked manufacturers to do.

USB-C gets complicated at the high end, but for basic functionality I think the standards committee did a very good job at making the cheapest way to do it the correct way, e.g. a USB-C to 3.5mm audio adaptor can be entirely passive, it just needs the right resistor in it.


Then a lot of phones don't support it, so it took me three attempts to find a usb-c to 3.5mm adapter that didn't have it's own DAC that would work with my phone's FM radio lol

Do you mind sharing? I was looking for something like this a couple years ago.

Audio Adapter Accessory Mode was deprecated last year so devices using it will be disappearing.

>e.g. a USB-C to 3.5mm audio adaptor can be entirely passive, it just needs the right resistor in it.

How does that work? is each USB-C host port, or downstream USB-C hub port required to contain a stereo DAC? Does the standard impose performance requirements like dynamic range, noise, minimum sample rate,...? Does it also mandate the jack can be used for mic / line-in? Does it similarily stipulate inclusion of an ADC in each port?


It doesn't mandate any of that, it's an optional feature.

The data pins are repurposed for analog audio, so it won't work with hubs. You'd of course need a DAC for output and an ADC for mic input, but the point is to replace a headset jack, so you'd have those already.

https://www.usb.org/sites/default/files/USB%20Type-C%20Spec%... (PDF, page 309)


Maybe, but there's no good excuse for this making it past the prototyping phase. If nobody plugged it into a USB-C power supply and noticed it doesn't work, that's negligent.

By 2019 or so, when USB-C was five years old, somebody on any product design team should have been aware this is a common problem and checked for it when selecting components.


The PCB designer could simply type "Type-C电路图" into Baidu and follow the instructions in the top result. But they couldn't be bothered.

It's not the usb c committee problem, the devices you are buying are out of spec

This is because the cable is 2 sided so it can't assume polarity

So it's a tradeoff for not having to guess how to insert the cable


> This is because the cable is 2 sided so it can't assume polarity

To clarify (and to tell my own tale on the topic):

The power pins on both sides should be connected in both a plug and in a socket. However, when it comes to the USB 2.0 data pins only the socket end must be double-sided (short A6 to B6 and A7 to B7).

Back when "Type C" was new, I wanted to build a project with it, so I got one of the first socket breakout boards available. I built a mechanical keyboard out of aluminium with a slot milled to fit that breakout board. After everything was painted and soldered did I plug it in and it did not work ... It took me a while of troubleshooting before I retried it with the cable plugged in the other orientation. The breakout board had connected only A6/A7. B6/B7 were not available.


>This is because the cable is 2 sided so it can't assume polarity

Not really. The USB-C connection pinout is symmetric about a 180 degree rotation, at least as far as power connections go. It's entirely possible (and common, e.g. when using passive converters) to just put power out of it constantly. The main reason for the signaling resistors is to avoid having power presented on the pins when it's not connected, which is more about avoiding corrosion or wear due to small sparks on connection.


And to avoid having two sources (perhaps with slightly different voltages) connected together and leading to hijinks. E.g. a usb A-C cable plugged into a USB-C power supply.

This was exactly my complaint when the USB C standards were coming in - having a universal connector means nothing I you need a specific cable and/or power supply to charge it. You might say it’s not spec compliant and that’s fine - but it’s still a USB C port. We’d all be better off if they had just kept it as micro usb because at least then I’d _know_ I need a different cable for it

Would it be possible to build some kind of adapter or C-to-C cable that just contains the missing resistors? (And also probably would have to block any USB PD communication, in case you plug in any device that actually does try to use PD. So the goal would be that the charger always sees a 5V requesting device without PD support while the device always sees a "dumb" 5V charger - regardless of what capabilities the device and charger really have)

It would still suck to have to use a special cable for charging, but at least it's better than not being able to use any modern charger.


Sure, just grab a C-to-A adapter and A-to-C cable. Doesn't block communication though, you could block it by using a 2-wire A-to-C cable.

OK, that's easier than I thought. And I think it should even block the PD communication as the CC line is not passed through.



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