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Comment by dragontamer | Hacker News Reader

Isn't CANbus a multi-drop bus? Do car companies run safety-critical functionality off of it?

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My understanding is that 10BASE-T1S is a replacement for CANbus. Whatever CANbus does, 10BASE-T1S should do it better. It happens to be Ethernet (albeit a much slower Ethernet), but Ethernet/IP/TCP is something modern programmers understand better than UARTs / CANbus.

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Actually, CAN XL is just around the corner with up to 20 Mbps vs 10 Mbps of 10BaseT1S. The other difference is that CAN XL has a paylod of 2048 bytes and will have data link layer security from the get go. While 10BaseT1S has just a little bit over 1 kbytes and MACsec is still ery expansive.

That said, both technologies are just prototypes and expected availability is in about 3 years.

> That said, both technologies are just prototypes and expected availability is in about 3 years.

OnSemi claims to have a production 10Base-T1s MAC-PHY now.

https://www.onsemi.com/products/interfaces/ethernet-controll...

I'm not an expert on automotive systems specifically, but in general with silicon level stuff like this when used in small, highly integrated systems, just having a PHY isn't nearly enough. Really, you want it to come baked into all the MCUs and MPUs your particular vertical uses so you don't need to waste time making your board designers wire up more shit and you can use the vendor library for your MCU instead of writing more shit. Most automotive microcontrollers come ready to go with a full CAN interface including all the libraries and such that you'd want, as well as dev boards that pin it out to whatever connector so you don't need to waste a board spin cycle creating an EDU.

So you kinda caught me here, I'm pulling my own vague spin on Cunningham's Law because in my industry (satellites) there has suddenly been some interest in using CAN for potentially fault-prone critical systems and this post caught my interest. Traditionally we use single ended buses for everything but traditionally we do a lot of things ¯\_(ツ)_/¯

10BASE-T1S is also kind of interesting in the same way, especially if it's potentially possible to use an existing linux network stack on top of it.

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