If you own an M2 MacBook Air or MacBook Pro there’s an update for your cable

https://www.macworld.com/article/1514105/macbook-air-pro-magsafe-cable-firmware-update.html

by cheeaun • 3 years ago

105 56 3 years ago

falcolas• 3 years ago

Probably see more and more of this as cables continue the trend of becoming computers that abstract the communication between the two plugs.

danpalmer• 3 years ago

A worrying trend given that most people buy the cheapest cables they can from companies who may have questionable motives or state backing.

hooverd2• 3 years ago

I'm more worried about companies forbidding third party cables or bricking cables you own. "Sorry, this cable was only licensed for 100 charging cycles. Please buy a new one, for your safety of course."

closewith3• 3 years ago

I wonder if there's a viable business model in "free" cables that inject ads into video streams.

powersnail• 3 years ago

Given the trend, I've really come to see all electric cables as not-yet-evolved computers, the same way every light bulb is a low resolution display.

ericboehs• 3 years ago

Can you brick your cable if you unplug it during the upgrade?

simlevesque• 3 years ago

That's what I was about to ask. It says that the cable should update itself transparently, but there can always be a chance of corruption. Maybe the cable keeps the old FW and only boots the new one if it is signed.

prewett• 3 years ago

Presumably there is space for two copies of the firmware, and once the new one decompresses and checksums correctly you update the firmware-start pointer.

mecsred• 3 years ago

Any reasonable manufacturer will rotate firmware images and have the bootloader fall back to the most recent validated image. Though I imagine this could happen if this practice becomes common enough that you get it on some 5$ gas station charging cable kinda thing.

avian• 3 years ago

A reasonable manufacturer looks at its bottom line and doesn't waste his engineering hours and BOM costs (double the flash memory!) on silly features like that. Either that or there are many unreasonable manufacturers out there.

readams• 3 years ago

Sounds like the firmware is actually stored in RAM and loaded when you plug in the cable.

tenebrisalietum2• 3 years ago

Really that shouldn't be called firmware (the actual firmware would be the fixed code that receives second-stage code from the host), but "software" doesn't fit that either. Maybe "controllerware" or something like that.

crazygringo• 3 years ago

Between this and "Help, Bing Won’t Stop Declaring Its Love for Me", man... HN headlines are making me laugh today.

Keep it up, technological progress! :)

noodlesUK• 3 years ago

I’m really surprised that these cables have updatable firmware. Surely that makes the attack surface that much larger?

Arrath2• 3 years ago

Just waiting for an 'illegal peripheral' exception when I try to use a cable condom, if those exist for anything other than USB yet.

peterkelly• 3 years ago

Apple's lightning-to-HDMI cable contains an embedded ARM SoC with 256MB of memory running the XNU kernel and a daemon that performs video decoding.

https://panic.com/blog/the-lightning-digital-av-adapter-surp...

baq• 3 years ago

I would like to post something substantial or whatever but how can you add anything to that...?

Mind blown.

adolph3• 3 years ago

That post is a classic and the first thing I thought of when I saw the headline.

b212• 3 years ago

Let’s add an accelerometer and gyroscope and then we can install Quake there and play by simply moving or tapping the cable.

The future is now, old man.

rollulus• 3 years ago

What could possibly be the use for any sort of logic in such cable be, given that on both ends of it there’s already a computer as well?

tesseract2• 3 years ago

* Translation between USB PD and whatever communication protocol runs on the center Magsafe pin (in Magsafe 1 and 2 it was Dallas 1-wire)

* Disabling power output when the cable is not connected to a computer, so that a metal object touching the spring pins can't create a dangerous short circuit

* Driving the LED

traceroute66• 3 years ago

What could possibly be the use for any sort of logic in such cable be, given that on both ends of it there’s already a computer as well?

Maybe because MacBooks can be charged via both USB-C and MagSafe connector it forms part of the safety mechanism against frying your motherboard and/or against arcing during connection/disconnection. Especially on the higher-end of the spectrum (e.g. 16-inch MacBooks with 140W MagSafe).

Sort of like the same way electric car chargers handshake before throwing amps down the cable.

cal85• 3 years ago

Just been scratching my head about this. Then I thought, is it just so they can detect authentic Apple cables and scold you for using an inauthentic one? Because iOS definitely does that. Some kind of challenge/response thing that requires a full Turing machine maybe.

Another thought was something to do with monitoring current or degradation but I cant see why they couldn’t do the same things from either the computer in the power adaptor or the computer in the actual computer.

duskwuff• 3 years ago

USB PD negotiation.

The MagSafe connector only has three distinct contacts (there are five pins, but it's mirrored), so there has to be some protocol translation between USB PD and the single control signal used in MagSafe.

Fauntleroy• 3 years ago

In a few more years, security will simply cease to exist entirely.

adolph3• 3 years ago

There’s no way to directly update the cable, but it should update automatically when plugged into your Mac. While you can check the firmware of your power adapter by attaching it to your Mac and clicking on the Apple logo in the top left corner of the menu bar, then About This Mac, System Report, and Power, it’s not clear how to check the specific firmware version of the cable.

So presumably there is some UART to the cable, and the cable to the power adapter. Is it all stuffed in the cable treated as a USB device or is there some proprietary control on the laptop side to communicate with the cable?

FateOfNations• 3 years ago

The only interface the computer normally has to the cable is the single control pin on in the middle of the MagSafe connector, so they are likely having to do something more sophisticated than UART.

(Apple could have had you plug the other end that has the USB-C connector into the computer to do the firmware update, but that isn't particularly intuitive or user friendly).

Maxious• 3 years ago

The chip uses the 1-Wire protocol, which is a clever system for connecting low-speed devices through a single wire (plus ground). The 1-Wire system is convenient here since the Mac can communicate with the Magsafe through the single adapter sense pin.

http://www.righto.com/2013/06/teardown-and-exploration-of-ma...

Magsafe 3 with USBC makes this even easier https://www.reddit.com/r/UsbCHardware/comments/11309f3/comme...

The Lightning comms protocol is interesting too https://hackaday.com/2015/02/14/reverse-engineering-apples-l...

exabrial• 3 years ago

When you have so much money and you don't know how to spend it... this is what you get.

conductr2• 3 years ago

It’s not clear what the firmware fixes or patches

I'm on M2 MB Air, and it seems odd to me that it (seems to) runs off battery even when plugged in and fully charged. Mine has been plugged in at desk for over a week, every day when I get on it says it's "Power Source: Power Adapter" yet it battery charging goes "On Hold" and dwindles as if it's running off battery all day. For example, it's mid-day for me and I'm at 79% but it's never been unplugged.

My last was a MB Air 2013 so maybe this is new behavior that I'm just not used to, but it seems strange. If I had to unplug and leave, I'd expect to be leaving with 100% charge.

Edit: "Optimized Battery Charging" was turned on as commenter mentioned, thanks for the tech support HN!

crummy• 3 years ago

Are you using the stock charger? I would see similar behaviour on my 2018 MBP when I used a USB-C charger without enough power.

davidbarker• 3 years ago

It sounds like Optimized Battery Charging may be turned on.

https://support.apple.com/en-us/HT212049

conductr2• 3 years ago

Yep, solved! Did not know about this setting (kind of buried in the Settings UI) - thanks for the tech support!

count• 3 years ago

80% is the 'ideal storage' condition for the battery. If it's always charging to 100%, the battery life is pretty dramatically shortened. Apple enabled this new charging manager that tries to learn your patterns (if you always unplug in the AM and leave with it, it'll learn to charge to 100% before you leave, for example). You can also click the battery icon in the tray (if you have that turned on) and tell it to charge to 100% 'right now', which only takes a minute or two with a full size charger.

This is a positive thing for the life of your battery, but if you do want to disable it, there's a setting in System Settings - click the 'i' in the circle next to Battery Health, and turn off 'Optimize Battery Charging' there.

robostac• 3 years ago

If it thinks it's going to be plugged in for a long time (based on previous usage) it'll pause the charging around 80% to preserve the battery health.

https://support.apple.com/en-us/HT

EricE• 3 years ago

One of the many utilities I love that comes with my Set App subscription is AlDente Pro. As others have pointed out, it allows me to set 80% as the max for my battery and it also will change the color of the LED on the magsafe connector to green once it gets to 80% and charging stops.

I had optimized battery charging enabled but my Mac seemed to always charge to 100% - with Al Dente I can force it to do what I want.

And recently I found Al Dente pausing charging because the battery temp got too warm. So then I went down a rabbit hole and found out I could tweak the fans up slightly higher with iStat Menus (also part of my Set app sub). There are other utilities that will do similar things - those just happen to be two I use, especially since I tend to use my MBP plugged in the majority of the time.

ripvanwinkle• 3 years ago

"Everything that can physically accommodate a processor and be powered, will eventually have a processor"

  - Anonymous

adolph3• 3 years ago

Goes like peanut butter with the jelly of Atwood's Law: any application that can be written in JavaScript, will eventually be written in JavaScript

https://blog.codinghorror.com/the-principle-of-least-power/

brenouchoa2• 3 years ago

I was having problems charging with my magsafe cable and for the last month was using the usb-c port to charge. Today i took if of the drawer and it is magically working again. I am using the beta mac os 13.2 so it may have solved my problem.

brenouchoa2• 3 years ago

I spoke too soon. My cable is still blinking orange after i plug it in. I will try to reboot.

fourmajor• 3 years ago

I've had a new MacBook Air M2 for a few weeks now. I've been charging exclusively with a USB-C charger. Is there any advantage to charging via magsafe?

If you own an M2 MacBook Air or MacBook Pro there’s an update for your cable

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