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Yes very seriously. Many microcontrollers come with CAN support natively, but no PHY for instance. So CAN is available for even the cheapest MCUs, not so with

Yes very seriously. Many microcontrollers come with CAN support natively, but no PHY for instance. So CAN is available for even the cheapest MCUs, not so with Ethernet. There is also a lot more supporting hardware required for Ethernet compared to CAN, and the price for producing a cheap Ethernet capable board is many times that of CAN. The galvanic isolation in Ethernet (magnetics) costs about 1W idle pr port, so the power budget is also on a whole other level. I spent the previous decade in embedded, designing both CAN and Ethernet-capable cobtrol systems for industrial applications. Ethernet is much more expensive than CAN, but can also be much faster etc. CAN and Ethernet normally do not compete for the same applications :)

eqvinox 2y ago
You're comparing CAN with classic Ethernet. You should be comparing CAN with SPE (Single Pair Ethernet), which was developed to replace CAN (among other things) and is in fact well on its way on doing just that - cars are getting built using it.
- throw-qqqqq 2y ago
  I know there are variants on the “classic” Ethernet. I was talking about vanilla Ethernet and answering a questions about “The most common standard known to mankind”, so I stuck with that.
  - eqvinox 2y ago
    The top-level comment was about "Ethernet". It was you who jumped to "Vanilla Ethernet".
    - throw-qqqqq 2y ago
      I know :) I added the “vanilla” prefix on purpose, to avoid someone mistaking my points on traditional Ethernet with the industrial variants. I limited myself to traditional Ethernet because most people think of that when they say “Ethernet”, but sure, it could technically be all of 802.3.
      - SAI_Peregrinus 2y ago
        Bring back thicknet for cars!
- throw-qqqqq 2y ago
  Even if we compare CAN to Single Pair Ethernet, most of my points still stand, do they not? SPE is still more expensive and complicated than CAN, but also much more capable (higher data rates etc.). PHY power consumption is much lower compared to traditional Ethernet, but still on another level compared to CAN. I’ve seen Ethernet chosen mostly when CAN (or RS485 etc.) is too slow or you want longer distances (cabling). I mean to clarify my point - not to bicker :) I don’t think I disagree with any of your points
  - eqvinox 2y ago
    I'm not actually sure 10base-T1S (which is the closest equivalent to CAN) uses more power than CAN. The maximum current rating for some random T1S PHYs is actually lower than that of some random CAN PHYs, but actual power consumption depends on bus usage patterns… Regarding being expensive and complicated… I'd say that's a question of proliferation. And the non-multidrop SPE variants are actually simpler than CAN in some regards I'd argue.
    - throw-qqqqq 2y ago
      Okay, interesting! Thanks for enlightening me. I’ll look into SPE. W.r.t. my point with “complicated and expensive”. Most IP-stacks require low double digit kilobytes of memory, where CAN can be much cheaper (can also be much heavier depending on the “CAN stack”), which rules out the cheapest MCUs. When I was in embedded, most cheaper MCUs (32bit <100MHz single core, 16kb SRAM etc.) didn’t support Ethernet as a native peripheral. I.e. required a jump from a Cortex M3 to M4 for instance. I haven’t followed things for around a decade though..

eqvinox 2y ago

You're comparing CAN with classic Ethernet. You should be comparing CAN with SPE (Single Pair Ethernet), which was developed to replace CAN (among other things) and is in fact well on its way on doing just that - cars are getting built using it.

throw-qqqqq 2y ago
I know there are variants on the “classic” Ethernet. I was talking about vanilla Ethernet and answering a questions about “The most common standard known to mankind”, so I stuck with that.
- eqvinox 2y ago
  The top-level comment was about "Ethernet". It was you who jumped to "Vanilla Ethernet".
  - throw-qqqqq 2y ago
    I know :) I added the “vanilla” prefix on purpose, to avoid someone mistaking my points on traditional Ethernet with the industrial variants. I limited myself to traditional Ethernet because most people think of that when they say “Ethernet”, but sure, it could technically be all of 802.3.
    - SAI_Peregrinus 2y ago
      Bring back thicknet for cars!
throw-qqqqq 2y ago
Even if we compare CAN to Single Pair Ethernet, most of my points still stand, do they not? SPE is still more expensive and complicated than CAN, but also much more capable (higher data rates etc.). PHY power consumption is much lower compared to traditional Ethernet, but still on another level compared to CAN. I’ve seen Ethernet chosen mostly when CAN (or RS485 etc.) is too slow or you want longer distances (cabling). I mean to clarify my point - not to bicker :) I don’t think I disagree with any of your points
- eqvinox 2y ago
  I'm not actually sure 10base-T1S (which is the closest equivalent to CAN) uses more power than CAN. The maximum current rating for some random T1S PHYs is actually lower than that of some random CAN PHYs, but actual power consumption depends on bus usage patterns… Regarding being expensive and complicated… I'd say that's a question of proliferation. And the non-multidrop SPE variants are actually simpler than CAN in some regards I'd argue.
  - throw-qqqqq 2y ago
    Okay, interesting! Thanks for enlightening me. I’ll look into SPE. W.r.t. my point with “complicated and expensive”. Most IP-stacks require low double digit kilobytes of memory, where CAN can be much cheaper (can also be much heavier depending on the “CAN stack”), which rules out the cheapest MCUs. When I was in embedded, most cheaper MCUs (32bit <100MHz single core, 16kb SRAM etc.) didn’t support Ethernet as a native peripheral. I.e. required a jump from a Cortex M3 to M4 for instance. I haven’t followed things for around a decade though..