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I believe this is the first ESP to gain Ethernet capability? I totally wish that a board would come with PoE… Because as it is right now, powering a fleet of

I believe this is the first ESP to gain Ethernet capability? I totally wish that a board would come with PoE… Because as it is right now, powering a fleet of those with USB power supplies is annoying as fsck…

anigbrowl 6mo ago
M5stack has PoE offerings
armx40 6mo ago
No. It’s there already. I used Ethernet on esp32-p4 and it nicely hovers around 90-100 mbps with lan8720 chip.
3form 6mo ago
This would be great indeed. On that note, why does the PoE capability often add such a big proportion of the price of various items? Is the technology really costly for some reason, or is it just more there's fairly low demand and people are still willing to pay?
- jwr 6mo ago
  PoE is not obvious to implement (take it from someone who has done it with a fair share of mistakes), uses more expensive components that normal ethernet, takes up more space on the board, makes passing emissions certification more complex, and is more prone to mistakes that ruin boards in the future, causing support/warranty issues. In other words, a bag of worms: not impossible to handle, but something you would rather avoid if possible.
  - ldng 6mo ago
    And what would a better alternative look like ?
    - timschmidt 6mo ago
      I wouldn't call it "better", but the least-effort path among hobbyists and low end gear is often 12v or 24v sent over a pair with Gnd and a forgiving voltage regulator on the other end.
    - jwr 6mo ago
      There is none, I never said PoE is "bad": it's a very good solution, it's just difficult to implement.
- Etheryte 6mo ago
  Whenever you combine two things into one, the complexity and cost go up considerably. A regular coffee machine is pretty cheap. Add high pressure so it can make espresso and it gets considerably more expensive. Add milk so it can make cappuccino, again more complex and expensive. The same holds for electronics. Isolating power when it's alone is fairly straightforward. It gets considerably more tricky and hence more expensive the moment you want to place any kind of a meaningful data signal in its vicinity.
- solarkraft 6mo ago
  I’m sure the other commenters are right, but I’m guessing market segmentation may play a role here too.
- easygenes 6mo ago
  A full-module add-on in this power class is about $7 at 1,000 unit scale [0]. It would be around $3 with your own custom PCB design in terms of BoM addon at scale. That’s power only. Add another dollar or two for 10/100 PHY. The trick is as others have said in what adding it to your design does in terms of complicating compliance design. [0] https://www.digikey.com/en/products/detail/silvertel/AG9705-2BR/21187225 https://www.digikey.com/en/products/detail/silvertel/AG9705-...
- throwup238 6mo ago
  Ethernet is already one of the most expensive standards because you need magnetics for isolation. Adding power on top of that is genuinely expensive.
- Aurornis 6mo ago
  PoE power supplies need to be isolated (except in rare exceptions) and handle much higher voltages than common USB-C or wall wart power supplies. They have to use a transformer and a more complex control strategy, not a simple buck regulator with an inductor. PoE inputs need to tolerate voltages several times higher than the highest USB-C voltages, so more expensive parts are used everywhere.
  - namibj 6mo ago
    Any Ethernet (well, any RJ45 you expect in a home/office) has to have at least 1500V isolation from the RJ45 wire to anything metal that can be touched or is a connector on the device. A PoE-only device with no electrical connectors besides the RJ45 can just use a very cheap RJ45 port with integrated magnetics and PoE allowance (tiny bit bigger wires and a center pin exposed, less than 50ct more than the cheapest RJ45 with integrated magnetics) and a cheap buck from 40~80V to e.g. 5V. Oh, and a cheap bridge rectifier and some signaling resistors to take care of input polarity and signal to the source that we in fact want the approximately 50V that could hurt a device not made for it.
    - shadowpho 6mo ago
      > cheap buck from 40~80V to e.g. 5V. That’s not a cheap buck lol. Order of magnitude more expensive then 12v not even mentioning capacitors that can withstand 80v is $$$ and your derating goes to shit
  - cruffle_duffle 6mo ago
    It sounds like the PoE spec was designed before the arrival of “IoT” type things like the esp32, raspberry pi’s, etc. How much of the complexity is a “fundamental electrical engineering problem” and how much of it is just a spec written to solve a different set of problems?
    - cpgxiii 6mo ago
      Almost all of the complexity of PoE is fundamental. To get enough power over 100m of ethernet cable (10x longer than USB) you have to run at much higher voltages like 48V. The same has eventually come to USB: for USB-C Pd to reach 240W, it also has to use 48V. There have long been lower-voltage "passive PoE" systems which expect a lower always-on voltage on some of the ethernet pairs (usually 12V, 24V, or rarely 48V), which can be very easy to implement so long as your users can handle the setup and incompatibility with other ethernet devices (in the most extreme case of passive PoE on 100Mb/s ethernet, you simply connect the positive pair to the input of the device and the negative pair to the ground, no additional hardware needed).
Geof25 6mo ago
The original ESP32 has Ethernet as well, I believe in the form of RMII. Then it has been removed from the chip, never specified the reason.
elcritch 6mo ago
Nah, ESP32's have had ethernet capability for a while and ESP-IDF supports it well. I've been using one I built for 5+ years now. Unfortunately RMII (ethernet phy) interface takes up a lot of the GPIO pins. This part looks like it'll remedy that issue. There's two ESP32 boards that have been around for a while with PoE: - https://www.tme.com/us/en-us/details/esp32-poe/development-kits-for-data-transmission/olimex/ https://www.tme.com/us/en-us/details/esp32-poe/development-k... - https://wesp32.com/ https://wesp32.com/ I'm more hopeful for single-pair ethernet to gain momentum though! Deterministic, faster than CANBUS, single pair, with power delivery: https://www.hackster.io/rahulkhanna/sustainable-real-time-lab-monitor-using-spe-2a38a6 https://www.hackster.io/rahulkhanna/sustainable-real-time-la...
- toast0 6mo ago
  > I'm more hopeful for single-pair ethernet to gain momentum though! I keep looking for a reasonably priced 10baseT to 10Base-T1L bridge... everything commercial seems too expensive (for me) and the two hobby designs [1] [2] I've seen are not orderable :( But I'm seeing more commercial options lately, so that's hopeful. [1] http://robruark.com/projects/10BASE-T1L/10BASE-T1L.html http://robruark.com/projects/10BASE-T1L/10BASE-T1L.html [2] https://matthewtran.dev/2024/08/10base-t1l-converter/ https://matthewtran.dev/2024/08/10base-t1l-converter/
  - elcritch 6mo ago
    The ManT1S linked by a sibling has a bridge. Still not cheap, but probably better than most commercial ones.
  - butvacuum 6mo ago
    any reason you won't send #2 to a pcbfab? include assembly if that's an issue.
- matt_trentini 6mo ago
  Waiting for my ManT1S: https://www.crowdsupply.com/silicognition/mant1s https://www.crowdsupply.com/silicognition/mant1s
deleted 6mo ago
[deleted]
amelius 6mo ago
> Because as it is right now, powering a fleet of those with USB power supplies is annoying as fsck… Therefore, wifi is more convenient than ethernet. You don't need long cables, just a local power source.
- albuic 6mo ago
  > You don't need long cables, just a local power source Which means batteries that have to be replaced and maintained or cables... So ethernet with PoE or even better SPE (single pair Ethernet) with PoDL (power over data lines which is PoE for SPE) is the best from my point of view
  - amelius 6mo ago
    I mean, if I just look at my house. There is just one ethernet outlet, but many power sockets. If I want to connect devices all over my house, the best way is to use wifi and usb power adapters. Not ethernet. Both solutions require 1 cable per device, but the first solution would require only short and thin cables, and the second solution would require very long cables which I don't know even how to do properly without milling my walls.
    - stinkbeetle 6mo ago
      Yep. Mains electricity is ubiquitous, highly interoperable, very reliable, very high power available per drop, can be outdoor capable, common standards, understandable by users, requiring no active components, with many on-call experts available who can come to fix problems or extend/alter connectivity. Mains power wall plates with inbuilt USB power outlets are even available at quite small cost if the look of the bigger plug and wiring is not appealing. PoE is much fewer of those things. Difficult to recommend it these days with wifi being fast and reliable and so widely used. Certainly not for average residential user.
      - cyberax 6mo ago
        On the other hand, _all_ the WiFi devices that I had at some point fell off the network, at least once. Including doorbells and cameras. While PoE devices just work. Another point is that mains power in my area can go down periodically. My PoE switch is powered by a Li-Ion UPS and can provide power for about a day.
exe34 6mo ago
Can't you run a 5V supply from where your router is all the way to every god damn device in your house, and then pretend the wifi is also going through it? If you just want it to be inconvenient, there's no reason to let a lack of PoE stop you!

anigbrowl 6mo ago

M5stack has PoE offerings

armx40 6mo ago

No. It’s there already. I used Ethernet on esp32-p4 and it nicely hovers around 90-100 mbps with lan8720 chip.

3form 6mo ago

This would be great indeed. On that note, why does the PoE capability often add such a big proportion of the price of various items? Is the technology really costly for some reason, or is it just more there's fairly low demand and people are still willing to pay?

jwr 6mo ago
PoE is not obvious to implement (take it from someone who has done it with a fair share of mistakes), uses more expensive components that normal ethernet, takes up more space on the board, makes passing emissions certification more complex, and is more prone to mistakes that ruin boards in the future, causing support/warranty issues. In other words, a bag of worms: not impossible to handle, but something you would rather avoid if possible.
- ldng 6mo ago
  And what would a better alternative look like ?
  - timschmidt 6mo ago
    I wouldn't call it "better", but the least-effort path among hobbyists and low end gear is often 12v or 24v sent over a pair with Gnd and a forgiving voltage regulator on the other end.
  - jwr 6mo ago
    There is none, I never said PoE is "bad": it's a very good solution, it's just difficult to implement.
Etheryte 6mo ago
Whenever you combine two things into one, the complexity and cost go up considerably. A regular coffee machine is pretty cheap. Add high pressure so it can make espresso and it gets considerably more expensive. Add milk so it can make cappuccino, again more complex and expensive. The same holds for electronics. Isolating power when it's alone is fairly straightforward. It gets considerably more tricky and hence more expensive the moment you want to place any kind of a meaningful data signal in its vicinity.
solarkraft 6mo ago
I’m sure the other commenters are right, but I’m guessing market segmentation may play a role here too.
easygenes 6mo ago
A full-module add-on in this power class is about $7 at 1,000 unit scale [0]. It would be around $3 with your own custom PCB design in terms of BoM addon at scale. That’s power only. Add another dollar or two for 10/100 PHY. The trick is as others have said in what adding it to your design does in terms of complicating compliance design. [0] https://www.digikey.com/en/products/detail/silvertel/AG9705-2BR/21187225 https://www.digikey.com/en/products/detail/silvertel/AG9705-...
throwup238 6mo ago
Ethernet is already one of the most expensive standards because you need magnetics for isolation. Adding power on top of that is genuinely expensive.
Aurornis 6mo ago
PoE power supplies need to be isolated (except in rare exceptions) and handle much higher voltages than common USB-C or wall wart power supplies. They have to use a transformer and a more complex control strategy, not a simple buck regulator with an inductor. PoE inputs need to tolerate voltages several times higher than the highest USB-C voltages, so more expensive parts are used everywhere.
- namibj 6mo ago
  Any Ethernet (well, any RJ45 you expect in a home/office) has to have at least 1500V isolation from the RJ45 wire to anything metal that can be touched or is a connector on the device. A PoE-only device with no electrical connectors besides the RJ45 can just use a very cheap RJ45 port with integrated magnetics and PoE allowance (tiny bit bigger wires and a center pin exposed, less than 50ct more than the cheapest RJ45 with integrated magnetics) and a cheap buck from 40~80V to e.g. 5V. Oh, and a cheap bridge rectifier and some signaling resistors to take care of input polarity and signal to the source that we in fact want the approximately 50V that could hurt a device not made for it.
  - shadowpho 6mo ago
    > cheap buck from 40~80V to e.g. 5V. That’s not a cheap buck lol. Order of magnitude more expensive then 12v not even mentioning capacitors that can withstand 80v is $$$ and your derating goes to shit
- cruffle_duffle 6mo ago
  It sounds like the PoE spec was designed before the arrival of “IoT” type things like the esp32, raspberry pi’s, etc. How much of the complexity is a “fundamental electrical engineering problem” and how much of it is just a spec written to solve a different set of problems?
  - cpgxiii 6mo ago
    Almost all of the complexity of PoE is fundamental. To get enough power over 100m of ethernet cable (10x longer than USB) you have to run at much higher voltages like 48V. The same has eventually come to USB: for USB-C Pd to reach 240W, it also has to use 48V. There have long been lower-voltage "passive PoE" systems which expect a lower always-on voltage on some of the ethernet pairs (usually 12V, 24V, or rarely 48V), which can be very easy to implement so long as your users can handle the setup and incompatibility with other ethernet devices (in the most extreme case of passive PoE on 100Mb/s ethernet, you simply connect the positive pair to the input of the device and the negative pair to the ground, no additional hardware needed).

Geof25 6mo ago

The original ESP32 has Ethernet as well, I believe in the form of RMII. Then it has been removed from the chip, never specified the reason.

elcritch 6mo ago

Nah, ESP32's have had ethernet capability for a while and ESP-IDF supports it well. I've been using one I built for 5+ years now. Unfortunately RMII (ethernet phy) interface takes up a lot of the GPIO pins. This part looks like it'll remedy that issue. There's two ESP32 boards that have been around for a while with PoE: - https://www.tme.com/us/en-us/details/esp32-poe/development-kits-for-data-transmission/olimex/ https://www.tme.com/us/en-us/details/esp32-poe/development-k... - https://wesp32.com/ https://wesp32.com/ I'm more hopeful for single-pair ethernet to gain momentum though! Deterministic, faster than CANBUS, single pair, with power delivery: https://www.hackster.io/rahulkhanna/sustainable-real-time-lab-monitor-using-spe-2a38a6 https://www.hackster.io/rahulkhanna/sustainable-real-time-la...

toast0 6mo ago
> I'm more hopeful for single-pair ethernet to gain momentum though! I keep looking for a reasonably priced 10baseT to 10Base-T1L bridge... everything commercial seems too expensive (for me) and the two hobby designs [1] [2] I've seen are not orderable :( But I'm seeing more commercial options lately, so that's hopeful. [1] http://robruark.com/projects/10BASE-T1L/10BASE-T1L.html http://robruark.com/projects/10BASE-T1L/10BASE-T1L.html [2] https://matthewtran.dev/2024/08/10base-t1l-converter/ https://matthewtran.dev/2024/08/10base-t1l-converter/
- elcritch 6mo ago
  The ManT1S linked by a sibling has a bridge. Still not cheap, but probably better than most commercial ones.
- butvacuum 6mo ago
  any reason you won't send #2 to a pcbfab? include assembly if that's an issue.
matt_trentini 6mo ago
Waiting for my ManT1S: https://www.crowdsupply.com/silicognition/mant1s https://www.crowdsupply.com/silicognition/mant1s

deleted 6mo ago

[deleted]

amelius 6mo ago

> Because as it is right now, powering a fleet of those with USB power supplies is annoying as fsck… Therefore, wifi is more convenient than ethernet. You don't need long cables, just a local power source.

albuic 6mo ago
> You don't need long cables, just a local power source Which means batteries that have to be replaced and maintained or cables... So ethernet with PoE or even better SPE (single pair Ethernet) with PoDL (power over data lines which is PoE for SPE) is the best from my point of view
- amelius 6mo ago
  I mean, if I just look at my house. There is just one ethernet outlet, but many power sockets. If I want to connect devices all over my house, the best way is to use wifi and usb power adapters. Not ethernet. Both solutions require 1 cable per device, but the first solution would require only short and thin cables, and the second solution would require very long cables which I don't know even how to do properly without milling my walls.
  - stinkbeetle 6mo ago
    Yep. Mains electricity is ubiquitous, highly interoperable, very reliable, very high power available per drop, can be outdoor capable, common standards, understandable by users, requiring no active components, with many on-call experts available who can come to fix problems or extend/alter connectivity. Mains power wall plates with inbuilt USB power outlets are even available at quite small cost if the look of the bigger plug and wiring is not appealing. PoE is much fewer of those things. Difficult to recommend it these days with wifi being fast and reliable and so widely used. Certainly not for average residential user.
    - cyberax 6mo ago
      On the other hand, _all_ the WiFi devices that I had at some point fell off the network, at least once. Including doorbells and cameras. While PoE devices just work. Another point is that mains power in my area can go down periodically. My PoE switch is powered by a Li-Ion UPS and can provide power for about a day.

exe34 6mo ago

Can't you run a 5V supply from where your router is all the way to every god damn device in your house, and then pretend the wifi is also going through it? If you just want it to be inconvenient, there's no reason to let a lack of PoE stop you!