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Lightning added chips that weren't necessary IMO. You don't need smart control over the low voltages/power that go over a lightning cable. Lightning chips were likely more about control.

USB-C _does_ require e-marked cables in certain cases where passing large amounts of power over a thin cable could be dangerous. I don't believe these chips are proprietary nor expensive - just marking silicon that replaced the old resistor system that was somewhat brittle and often wrong.

You're correct and shouldn't be downvoted.

If you're considering downvoting them, there's news articles about when Apple caved and allowed 3rd party cables.

Just waiting for a time when we can say this about Apple and third party repairs.

They've caved somewhat: https://www.apple.com/nz/newsroom/2019/08/apple-offers-custo...

The independent repair program is bullshit and is just a marketing move to try to appear good and avoid regulation being passed. Louis Rossmann (a popular unauthorized repair shop owner) explains it: https://www.youtube.com/watch?v=0rCUF-V1esM

I'm more concerned about what's not clarified: What are the costs to these independent repair specialists? Are they being charged exorbitant fees to keep Apple's in-house repair options more competitive? What cut is Apple taking, if any, per repair? Does Apple guarantee a repair made through these independent providers isn't going to result in a bricked device down the road? Can consumers see a cost breakdown of parts and labor like we can with repairs to non-Apple devices? And what criteria is being used to determine an "authorized" third party? Is that criteria biased against critics of Apple's platform? Is this considered a "license to repair", and if so, under what conditions is Apple reserving the right to revoke that license?

I have more questions than anything else.

Thunderbolt 3 (and probably USB4) requires chipped ('active') cables at lengths over 0.5m, but considering you're pumping 40Gbit of data over it, it kind of makes sense.

For Lightning, yeah, there's basically no reason except for the 'Made For iPhone' program, and it isn't even effective at that since Chinese cable makers just clone the keys of the official stuff.

Couldn't whatever EQ/delay compensation is performed by the chip just be moved to the PHY?

The chips in MFI program were pretty much DRM.

Indeed, I believe 40Gbit Ethernet doesn't need active cabling either.

Not exactly - at very short ranges, you can use DAC cabling, "Direct Attachment Cable". Those directly connect SFP signals, but afaik they still have circuitry inside its just easier because the cable is known length and characteristics - in exchange the cable is rather thick and unwieldy. Generally it works well inside rack for connecting servers to ToR switches and that's it.

40Gbit DAC is even more annoying because unless the cable is a bit more active, it's essentially 4 10gbit DAC in one sheath.

there is no such thing as 40G ethernet. you can see this easier with optical - there are literally 4 cables inside the one thick cable. you're talking about quad ports - 4x 10G connections in one wide QSFP. in fact, all a breakout cable does is take the 4 wires in that 40G cable, and unwraps them. Ethernet currently goes to SFP28, which is a 25G connection. fibre channel (as in SAN, not LAN) in theory currently goes to 128G, and in practice you can buy buy hardware that goes to 64G. FC cannot run over copper.

Second, yes, some does require active cables with DAC. which does not stand for "cable" like the other comment says. DAC is direct attach copper (as opposed to optical). Without an active cable you're limited to 5 meters, although you can risk it and get a 7 meter passive cable. usually, 7m is already active, and 10m+ is guaranteed to be active. The reason you can even do 10G over copper is because it's cat6. Have you seen that cable? It's twinax - more like the cable from your TV antenna. That's not viable for a phone.

What you are talking about is 10G base-T. That does not need active cabling. but again, you can't compare that to a tiny thin lightning cable.

It could, but it already was hard for Intel to get Thunderbolt adopted because the controller is rather expensive. My guess is that they assumed most people would only use it for short distance connection and thus they moved the cost of EQ to chipped cables for those who would truly need it.

Lightning cables have exposed contacts - While at 5V, this does not pose a significant shock risk, if full current were available, brushing the connector against metal could result in sparks and damage to the connector or power supply. Additionally, if the connector gets wet, the DC voltage will result in electrolytic corrosion. This still does happen even with the limited current provided before the handshake, just slower. (Don't!!!) try charging a phone with official cables and a power bank in the rain or letting a plugged in lighting cord's lightning end sit in some soup

Cables with electronics in them are useful for protections like this, and to facilitate safe interoperability of multiple voltage and current sources and sinks like on USB Type-C. The question becomes, is the protocol implemented in a simple, open consumer friendly way or is it implemented with other nasty antifeatures.

Couldn't all of the protections on current delivery be implemented in the interface on the other end of the cable, though? This is the approach taken by basically every other standard for negotiated power delivery. Even things like 802.3af which manage to deliver 48v at nearly an amp and with the complicating case of many valid devices not really tolerating any current delivered.

The other end of the cable is generic USB and can often be a naked, logic-free 5V supply.

I’ve cut the ends off way too many USB cables just to expose those red and black wires.

And surprisingly many cables even have just those two wires inside of them and can't carry any data

The other end being USB-A power adapters? There’s a vast number of those of varying quality. Some have zero logic and just output 5V/1A. No way they could be trusted for this purpose.

call this a “safety in depth” approach

So we should buy expensive cables and cheap power supplies?

There was already a huge installed base of cheap power supplies

Those cheap power supplies are ubiquitous, so it's more about Apple building their cables to exist in the built environment than dealing with the fallout of consumers busting up their expensive phones by charging them on whatever's lying around.

Guarantee there was a consumer study where they compared reactions between these scenario.

The manufacturers knows that if it’s their product in contact when a user is shocked, they will get some blame even if it’s “really” the sketchy power supply’s fault. And since some cables have these safety features already, anyone making cables without them will appear extra negligent when bad things happen.

The world is unfortunately not very efficient.

No I think the GP meant the port on the iPhone as the “other end”. In other words, why not have all of the protection logic built into the phone?

If the cable is dumb, it can’t switch the +5v power coming from a USB supply. If it can switch it, it’s not dumb.

just as an example, imagine you end up putting a fuse in the cable. If the fuse blows, then the cable can be easily replaced. A chip in the iPhone.... not so much.

Though likely there's something in the phone _as well_ as the cable.

Isn't direct current component ignored by default just because Ethernet devices are galvanically isolated? I thought even if you applied some DC voltage to Ethernet without proper PoE negotation, nothing would happen at all.

In a nutshell: EMI (Electromagnetic Interference) is the main reason why cables got smart in the first place.

Many people in IT think, that data is just 1s and 0s. But in reality we are living in a physical world and as such some form of power is used to transmit those 1s and 0s. This power may is electrical power in terms of voltages with defined generated current or in terms of current with defined voltages (20mA communication heavily seen in industrial equipment). If you have a slow communication link, EMI and other environmental thinks like temperature is not much of an issue. But as faster you like to communicate you need to cope with those things. The electrical contacts in the connectors doesn't help. So people started to put the transceivers into the cables. Those transceivers with additional electronics like ringing suppression circuitry and other "magic" are then best fitted for the desired cables for the desired environments. Then you started to makes those cables smart like to detect the capabilities of the cables like is it really possible to talk at 10Gbps or is it more a cheaper type where 100Mbps is the max. As more smarter those cables get people get creative to put other things in it like "hey, the cable could become a converter as well".

> In a nutshell: EMI (Electromagnetic Interference) is the main reason why cables got smart in the first place.

Considering the main use case (almost exclusive use case) for lightning is for charging and nothing else, I wonder why they have to be so complicated? Shouldn't charging cables work with Vcc/Gnd only wired and a dumb power 5V/2A source? Why is my phone doing some complex detection/negotiation of cables/chargers when I plug it in? Why is a charger considered an "acceessory"?

Primary use-case for a smart phone is the web-browser and networking array.

That doesn’t mean you can remove the microphone.

Optimising the common case in this instance will remove all other possibilities.

You don't have to remove negotiation and complexity from the system when it's used for data. My question isn't why those systems are there so much as why they are needed for the charging use case. E.g.: why do chargers even need more pins wired than +5V and ground? Is there really such a large benefit from making chargers "smart"?

It doesnt actually matter what the almost exclusive use case is, the sheer ability of being able to transmit data in this case and other available uses makes the apparent need of a chip. Keep in mind these chips bring safety to the exposed pins and some negotiation is needed to understand whats on the other side of the cable in order to better handle it. (That and to make it possible to control 3rd party market accessory) A charger is considered an accessory because it is merely a utility for a device, it is made to charge stuff. Take a purse for example, it merely holds stuff and nothing more, you can change a purse and the other one will do the exact same job.

> A charger is considered an accessory But because it is merely a utility for a device

Yes I understand the reasoning behind it, but I don't understand why it's not seen as a much more important feature to be able to load from anything anywhere so long as the +5V and GND pins are working, regardless of what power source and cable it is.

That there is complexity when the lightning cable and connector is used as a data transfer cable I understand. I don't understand why the charger mode isn't dumb as rocks.

Because destroying chargers with too much current, or lighting cables on fire is a bad PR?

I have a lot of cheap chargers, and they give out all sorts of crazy stuff. One drops the voltage to like 3.5 volts with 1 volt of ripple under load. Another shuts down the port completely if you draw >.6A.

It is really hard to tell how much current can one draw safety.

While you might only use Lightning for charging, it is an accessory port. It can transmit data to computers, it can talk to SD cards, it can output HDMI.

You could argue you that you don't need any of those features, but Apple disagrees and that's why lightning is not just a 5V DC jack.

My argument (or question) isn't that Lightning is useless or that I don't need it, but that charging shouldn't require a lot of complex communication. I don't understand what it is about charging that requires both ends to have microcontrollers

Lighting is for charging and nothing else? Really?

Tell that the people, who want to connect their professional microphone to make TikToks. Tell that the people, who want to connect a stick drive to offload their videos. Tell that the people who provide different accessories.

Lighting has evolved from the 30-pin Dock connector. The 30-pin Dock connector was the idea to combine charging, USB, and some analog stuff into one single connector. At that time USB provided only 5V and 200mA. Apple was one of the other who improved USB charging by allowing more power. But for the sake of compatibility, you cannot just do this, you need to negotiate it. It is like every USB up to USB3 starts in USB1.1 to negotiate the possibilities.

So, Lighting was not developed out of thin air. It was developed with a history, like many many other communication protocols and standards. Even as Apple is known for cutting of old ties easily, if you look really deep into the details, you will always find compatibility to old out-dated technologies. Its like you still find the good old 8051-core in many things, like even dead simple and cheap charge controllers.

The potential EMI of cables you're talking about can be fixed with good shielded cables, they don't need active chips inside them.

Shielding helps. That is correct. But it does not help with ringing, temperature and other such kind of problems. And shielding is expansive.

What shielding does not help as well is contacting problems because of corrosion or dirt. We are talking about a consumer product and not a well designed any lay out wiring by some system integrator. Consumers are doing all kind of bad things to connectors and will complain if it does not work.

And how does having active chips in a 1m cable help?

by replacing a cable instead of taking apart your iphone and soldering the chip in the phone when an electrical spike comes through from your open contact getting water on it. but you're asking about throughput. the reason active cables exist is because the amount of interference in a cable varies - that little sheath of tin foil in a lightning cable does almost nothing. you need an axial cable for that - which is what ethernet uses for passive direct connection. it's as thick as the coax cable for your tv antenna. your idea I guess is to plug in that thick non-bendable cable into your phone? or is it to put that chip into every usb-A power source in the world? or is it to only use approved apple usb power supplies - instead of the millions of plugs out there at airports, hotels, laptops, existing ac/dc converters from hundreds of vendors? so which of these is your plan instead of the chip in the cable?

I know, I know, usb cables don't need a chip inside, why does lightning. because usb cables are a useless random mess. lightning cables are not - they run at the guaranteed speed, they charge at the guaranteed watts, and they have no issues with shorts despite having contacts exposed and reversible, unlike usb. and usb-C? well, there are active cables available for that, which tackle the issues described with a chip in the cable. just like lightning does.

The chip's responses are how the iPhone knows what device / cable type is connected to the port- at least that's what I understand from this.

Why wouldn't the device ask the port directly? A chip in the cable means that the device asks the cable, which then asks the device.... why not cut out the middleman?

If the device is dead, then it can't ask the port.

This is also tied to fast charging (and whether the device will support it)

Couldn't it provide the low power until the device is powered enough to answer the fast charging question?

Also, wait... if the device is dead, how does the CABLE know that fast charging is supported by the device?

I think the link describes this tangentially. The minimal 10mw - 15mw current that high-five allows on a cable that hasn’t completed a handshake is enough to charge the capacitor for secure boot and trident which then can handshake with 0x74 to receive 5v 1a source. When the kernel boots the rest of the handshake process can be completed to increase the current.

That’s at least my understanding from the document.

One use-case comes up in the article: the chip in the cable is able to probe information from the device even when the device is unpowered, essentially acting as a microcontroller grabbing some of the device's less-guarded peripherals for itself.

Is it solely to try to prevent third-party manufacturers? Is it for the cable to announce to the port that it supports certain specifications of power or data? (But why would that require a chip instead of just some kind of "dumb" extra pin that has some basic electrical property that can be read?) Is it something else?

My theory is that it started as the former and then they realised it would seem less suspicious and more friendly to also use it for the latter.

In a nutshell, the answer is that the Lightning cables just seem simple, but they're not.

How would you maintain such a margin on the cables if they could be "dumb"?

Considering they're already being ripped off anyway, and most consumers don't know they're "smart", the margins would be higher selling a "dumb" cable that costs less to make, at the same price as they sell them at today.

The last time I looked, the money Apple earned from the entirety of the MFi program — not just cables, but every single third-party Apple accessory on Earth — made up less than one half of one percent of their annual revenue. It's such a vanishingly small part of their business.

It's far more likely that the purpose of MFi is to make sure that any officially licensed accessories aren't pieces of shit that Apple will cop the blame for. Most users aren't going to blame the cable manufacturer when their phone won't charge properly, since the vast majority of people have no idea about the complexities of modern charging protocols, so they're going to mistakenly think the phone is at fault and blame Apple.

> every single third-party Apple accessory on Earth made up less than one half of one percent of their annual revenue

That makes me even more angry about the ridiculous price of these accessories