wESP32: Wired ESP32 with Ethernet and PoE

A low cost ESP32 core board with Ethernet and PoE for convenient "single cable" deployments

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The ESP32 is very popular among makers as the brains for various projects. Usually it is connected to the internet with WiFi, but an often overlooked feature of the ESP32 is that it also contains an Ethernet MAC. This project aims to create a hacker friendly ESP32 + Ethernet + PoE core board to make it very easy to apply the power of the ESP32 in new areas such as home automation, factory automation, smart buildings and data centers, where the use PoE provides major advantages in installation and maintenance.

Due to the high power consumption of WiFi, most ESP32 based systems already require wired power. Since you already need a wire, why not provide power and connectivity through a single wire and bypass deployment hassles associated with WiFi credentials and RF performance in hard-to-reach locations?

Plus the high power available with PoE makes it possible to not only make ESP32 based sensor nodes, but to create smart network-connected actuators as well!

I just completed an application-specific ESP32 based PoE board for a customer, and it got me thinking: how much interest would there be in a generic ESP32 PoE core board?

By using PoE, a single cable provides power as well as connectivity, easing deployment headaches for large installations.  PoE can provide up to 12.95 W to a load while PoE+ specifies up to 25.50 W.  Plenty for an ESP32 which takes only a watt or so, making it possible to power other loads.  PoE capable network switches and injectors are also becoming quite common and have come down in price as well.

The nice thing about the ESP32 is that it's low cost and powerful, and provides WiFi and Bluetooth in addition to Ethernet.  So even if a deployment would be mostly Ethernet and PoE based, it would still be possible to connect a node with WiFi powered from another source if necessary.  Or it could be set up as an access point for other WiFi or Bluetooth LE based sensors.

While it would be nice to support as much power as possible, previous experience has taught me that high power opens all sorts of cans of worms related to heat dissipation and EMI.  So it seems prudent to not start at the highest power levels possible.  Some potential users also showed interest in compact, very low power systems, but there are plenty who were excited about the idea of having a decent amount of power available.  So I decided to take the middle road and do a 12.95W PoE class 3 design to start with.

The ability to use local power instead of PoE is a nice feature, but also adds complexity and cost.  The problem is that PoE uses 48V nominal to reduce wiring losses, but commonly available wall warts use lower voltages for safety.  Supporting both would require the circuit to support for a wide input voltage range making things more complex.

So I settled for the following solutions: local power can provided either by adding a PoE injector, or through the (optional) USB port.  Of course, from the USB port, only 5V will be available.

Talking about the USB port, several potential users expressed the opinion to not burden every board with something that would likely only be used during once during programming and never again after that.  I agree, so I made the USB programming/terminal port an optional module.

Other than those concerns, I want this module to be fully isolated (to prevent issues with long cabling), full featured (Ethernet, WiFi, Bluetooth LE, many ESP32 pins exposed), low cost and small.


Mechanical drawing of the wESP32 rev 3

Adobe Portable Document Format - 88.38 kB - 01/07/2020 at 16:37


Eagle CAD source files of the wESP32-Prog programming submodule

Zip Archive - 50.43 kB - 10/07/2019 at 14:41



Schematic of wESP32-Prog programming submodule

Adobe Portable Document Format - 19.49 kB - 10/07/2019 at 14:41



Schematic of wESP32 rev 3 with PMS150C to manage PHY reset

Adobe Portable Document Format - 43.55 kB - 03/19/2019 at 23:10



Complete schematic of wESP32 core module

Adobe Portable Document Format - 45.40 kB - 04/20/2018 at 18:30


View all 10 files

  • Second production run

    Patrick Van Oosterwijck05/10/2019 at 18:36 0 comments

    "Silicognition" PMS150C-559

    As mentioned in the last update, I ordered factory programmed Padauk PMS150C-U06 chips from Sino-Mos to provide a reliable reset for the PHY chip on every board.

    I expected everything to be OK with them, but you never know 100% for sure if everything was understood correctly when dealing with China, until you actually have something in-hand. For one thing, I was relieved that they had indeed re-reeled them. It would have been a big bummer if I would have received a bag of loose SOT-23’s. :)

    Then I had to make sure they were indeed programmed. So I reworked another 12 boards from the first batch that didn’t initialize the PHY correctly with chips from one of these reels, and after rework they all work flawlessly!

    Getting these chips has actually been a smoother experience than I had expected. It’s kind of cool to now have a low-cost custom chip that does exactly what I want it to do, with its own partnumber and everything. PMS150C-559 is now forever an “ESP32 Ethernet PHY reset manager”. Maybe I should write a datasheet for it. :)

    Also, since I have 9,000 of them, I can definitely spare some if anyone is making their own ESP32 board with Ethernet and wants a canned solution to deal with the LAN8720A PHY reset. There’s an updated schematic that shows how the chip is used on the new wESP32 revision. So get in touch if you want to buy some.

    Rev 3 PCBs

    I took a little risk and ordered new PCB panels that use the PMS150C-559 before I had verified the factory programmed chips. But it had all been taking much longer than expected already and some backers have been wondering when they’d receive their reward, so I tried to recoup some time that way.

    Having everything in-house I made a kit to send to a CM I was going to try in Mexico.  That's when things started to go really sideways.

    The scourge that is customs

    The first customs issue I ran into: how to do the paperwork correctly. This was going into Mexico temporarily just to have it assembled and then it was coming right back to the US. I sought advice from the CM and a local export company, and yes, I received information on some generalities, but no one really gave me any concrete answers on what codes to use, exemptions to claim or checkboxes to tick. So after wasting almost a week waiting for guidance I gave up and shipped the box with the documentation as good as I could figure it. I marked the shipment with the AES 30.37(q) to indicate a temporary export that would be returned within a year. Whether that is correct or not I don’t know. Nobody had told me what to do and it seemed the right thing to do.

    DHL got the box to Mexico after 4 days or so. Then the trouble started. First they claimed they couldn’t contact the CM at the telephone number I had been given and had put on the forms. They wouldn’t tell me why they needed to contact them. DHL was giving me options like “we can send your package back, or send it somewhere else for an extra charge, or we can destroy it for you (!)”. This nonsense took a week or so, a week of anxious freaking out for me. Then after wasting what they must have deemed sufficient time, they somehow did manage to get in touch with them and supposedly needed a tax ID from me. I run a passthrough LLC and certainly wasn’t going to give them my SSN! That sort of blew over after some work done by the CM and then they found that the contents of the box didn’t match the PI I had included. This was partially my fault: I had based the PI on the BOM, but even though neither me nor the CM cares about the exact part number of a reel of resistors, of course customs paper pushers do. I also had included some full and partial reels in the kit and amounts on the PI didn’t match. I really didn’t think anyone cared just how many parts were left on a partial reel, but of course they did.

    What a joke. None of it should have mattered of course. The parts are temporarily...

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  • The PHY reset saga

    Patrick Van Oosterwijck03/11/2019 at 16:09 2 comments

    Finally, a long overdue update! The silence doesn’t mean we’ve been taking it easy, on the contrary: we’ve been hard at work to make the wESP32 even better!

    A yield problem

    After the initial build of 245 units, we were able to ship 205 units that were good right away. There were various issues with the remaining 40, but the vast majority of them had the same problem: the Ethernet PHY would not get initialized properly.

    The LAN8720A Ethernet PHY is kind of a difficult part. It has several pins that have double use: during reset their logic level indicates various configuration settings, while after reset they are used in the RMII interface to communicate with the ESP32. An extra difficulty is that the chip expects the 50 MHz clock to be present during reset, so the chip can clock in these configuration settings.

    Unfortunately, the ESP32 by default uses the IO0 pin for the Ethernet MAC clock. (More options have become available for dealing with the Ethernet MAC and PHY clocks, but because IO0 was the first option available in the SDK, it enjoys the broadest firmware support so that’s why I keep using it. Plus to keep as many other ESP32 pins as possible available to the user!) The ESP32 IO0 pin is kind of a difficult pin as well, since it is used on reset to determine whether the ESP32 should go into programming mode or run the current firmware. So we have a perfect storm of an IO0 pin that needs to be high at boot to run normally, but low at boot to go into programming mode, and needs to have the 50 MHz clock on it after boot to allow Ethernet communication, and that before the PHY comes out of reset.

    When I designed the wESP32, I just looked at how Olimex dealt with the IO0, ESP32 reset and PHY reset on their ESP32-GATEWAY and copied that for the wESP32, figuring they must already have found a good solution since this was a product in production. On my first hand-built prototypes, it all worked well, so I went ahead with it in production. Then I found that more than 10% of the boards had an issue. Interestingly, in their latest revisions, Olimex has changed their product to use IO17 as PHY clock output to bypass the whole problem! This might be a smart thing to do, but I am loath to make backwards incompatible changes and take a precious GPIO pin away from the user. So I started looking at other ways to deal with this.

    Looking for a solution

    I needed a solution that would act as a reset manager for the 50 MHz oscillator and Ethernet PHY and would be triggered by the EN signal to the ESP32. When EN is low on power-up and when triggered by a programmer, the 50 MHz oscillator needs to be off, so the programmer can drive the IO0 pin low to enter programming mode, or the IO0 can stay pulled high and the system boots. The PHY needs to be kept in reset as well, because its reset can only be released after the 50 MHz clock has started up. After the ESP32 has had the opportunity to determine the boot state, the 50 MHz clock needs to be turned on, and only after the clock signal is present can the PHY reset be released.

    I had assumed there would be plenty of low cost, SOT packaged voltage detectors and reset managers that could replace my existing solution in the space I had available, but to my great surprise, nothing I could find in the market really seemed to fit the bill. There are plenty of supervisors that monitor multiple voltages and generate a reset, but I couldn’t find any low cost options that monitor one input and generate two reset signals with separate delays.

    So I started thinking outside the box: did I really need to add a little microcontroller to do this? There are several microcontrollers that are cheaper than higher end supervisor chips, and it would give me full flexibility to generate the reset signals exactly how I wanted them. On the other hand, I didn’t really want to deal with programming this micro on every board. I would need to add programming pads and a manufacturing...

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  • Don't blow up your Ethernet phy!

    Patrick Van Oosterwijck01/16/2019 at 16:29 0 comments

    You may have noticed a warning at the bottom of the MongooseOS demo in the demo code repo, about accidentally blowing up the Ethernet phy while playing with MongooseOS demo code.

    I didn’t find any time to pursue this further, but I have to give the people at MongooseOS credit for getting to the bottom of this! I received this message from them:

    We did some research, and found the problem with ethernet. It happened to be quite stupid: the default config for the built-in LED used pin 22, which conflicts with the ethernet TX.
    So, this command should set the board correctly:
    mos flash esp32
    mos config-set eth.enable=true eth.mdc_gpio=16 eth.mdio_gpio=17

    This highlights an issue that can happen with other firmwares as well: misconfigured pins doing damage to the phy. By default, the wESP32 ships with MicroPython installed and it is configured correctly out-of-the-box for the Ethernet phy as it is configured on the wESP32. If you load different firmware though, it is your responsibility to ensure the ESP32 pins are configured correctly and will for instance not configure an ESP32 pin as an output that connects to a phy output, and thus cause a short. Please refer to the schematic to make sure. The wESP32 website section on Software provides more information on wESP32 support in different environments.

    If you have ordered one or more wESP32's, I recommend you try it with the default MicroPython firmware when you first receive it, to confirm the hardware is sound and it receives an IP address (check with lan.ifconfig()) from DHCP over Ethernet, which only happens if the phy is working. All units are tested to do this before they are shipped, but this way you can prove to yourself the hardware is OK and nothing bad happened during shipping. After that you are free to use whatever firmware you want of course, but I will not replace defective units once they have been flashed with different firmware, as I cannot know what happened to them.  Thanks for understanding!

  • We are shipping

    Patrick Van Oosterwijck01/16/2019 at 16:24 0 comments

    On Monday 1/7, we finally received completed panels from Colorado Tech Shop!

    So we spent most of this week doing final assembly (installation of two through-hole electrolytic capacitors and the Ethernet jacks) and testing for all 245 boards in the first batch. I am quite pleased with the result, I hope you backers will be happy as well!

    Some boards were used for internal testing, some had to be sent back to Colorado Tech Shop for rework after finding issues during test, but today we were able to ship the first 205 units to Crowd Supply for delivery to backers next week.

    One of the boards was used for an experiment. I wanted to see if the board worked with the AI-Thinker ESP32-S module instead of the ESP32-WROOM-32:

    I’m happy to report it seems to work just the same, so this module could be used to provide a future U.FL antenna connector option!

  • Production update, and testers!

    Patrick Van Oosterwijck12/30/2018 at 06:39 0 comments

    Last week it dawned on me that time keeps passing and I hadn't given much thought yet to how I was going to test the wESP32 and wESP32-Prog boards before we ship them!  A very important issue to start cranking on, especially with holidays and vacation eating up a good amount of time.

    wESP32-Prog tester

    The wESP32-Prog board is quite simple and because of this, the tester can be simple as well.  Building the tester only took half a day and this is what I ended up with:

    The hardware consists of a little STM8S103F3 board that can be had for less than a dollar on AliExpress.  I had it laying around and all I needed for this was a simple UART capable chip, so this was perfect.  I used the Sduino project project to speed up firmware development.   It looks slightly different from normal Arduino code because the SDCC compiler doesn't support C++, only C.  It was simple enough to get it to work though, resulting in this code:

    // wESP32-Prog tester using STM8S103 board and sDuino
    #define IO0   PA1
    #define EN    PA2
    void setup() {
      // Initialize digital pin LED_BUILTIN as an output.
      pinMode(LED_BUILTIN, OUTPUT);
      digitalWrite(LED_BUILTIN, 1);
      // Initialize EN and IO0 test pins as input with pullup
      pinMode(IO0, INPUT_PULLUP);
      pinMode(EN, INPUT_PULLUP);
        // Init serial port to 115200 bps
    void loop() {
      // Read a byte from serial port
      int c = Serial_read();
      // Did we get a byte?
      if (c >= 0) {
        // Set lowest bit to value of IO0
        c = (c & 0xFE) | (digitalRead(IO0) ? 0x01 : 0);
        // Set second lowest bit to value of EN
        c = (c & 0xFD) | (digitalRead(EN) ? 0x02 : 0);
        // Echo byte back with altered IO0 and EN bits
        // Set the green LED state according to the second highest bit
        digitalWrite(LED_BUILTIN, (c & 0x40) ? 0 : 1);

     All this does is when a byte comes in, echo it back with the bottom two bits replaced by the current state of the IO0 and EN signals.  The second to highest bit also sets the tester board's on-board LED state.

    This firmware works in conjunction with a little Python script on my Linux box:

    #!/usr/bin/env python3
    import os
    import glob
    import serial
    import time
    from termcolor import colored
    while True:
      print("Waiting for wESP32-Prog...")
        ports = []
      while not ports:
        ports = glob.glob('/dev/ttyUSB*')
      print("Serial port detected, waiting for access...")
        while (not os.access(ports[0], os.R_OK|os.W_OK)):
        print("Testing wESP32-Prog...")
        test_ok = True
      s = serial.Serial(port=ports[0], baudrate=115200, timeout=0.1)
      res =
      if (res not in [b'0', b'1', b'2', b'3']):
        print(colored("ERROR: Serial data did not echo correctly, is the tester connected?", 'red'))
        test_ok = False
      if (res != b'3'):
        print(colored("ERROR: IO0 and/or EN pulled low when neither is asserted!", 'red'))
        test_ok = False
      if ( != b'1'):
        print(colored("ERROR: EN not pulled low correctly!", 'red'))
        test_ok = False
      if ( != b'3'):
        print(colored("ERROR: IO0 and/or EN pulled low when both are asserted!", 'red'))
        test_ok = False
      if ( != b'2'):
        print(colored("ERROR: IO0 not pulled low correctly!", 'red'))
        test_ok = False
      if (test_ok):
        print(colored("OK! All tests passed.", 'green'))
      print("Please unplug wESP32-Prog.")
        while ports:
        ports = glob.glob('/dev/ttyUSB*')

     What this does is wait for the wESP32-Prog board to be plugged in, which will create a /dev/ttyUSB0 device.  For some reason, trying to immediately open the serial device after this threw an access error, so we wait until it becomes accessible and then open it.

    Testing ensures that when we send a byte, the STM8 micro echoes a (modified) byte back to us.  We do this with various states of the RTS and DTR signals which control...

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  • Crowd Supply campaign ending!

    Patrick Van Oosterwijck11/12/2018 at 17:51 0 comments

    The Crowd Supply campaign has been going very well and will be ending soon, so if you haven't put in an order yet and you want one, now is the time! :)

    I've been putting quite a bit of work into the software side of things during the campaign, to make it as easy as possible for anyone wanting to design something with this to get started.

    First of all, there's now a web site at  It contains information on the hardware and on software development in different environments.  Most importantly, it contains a link to the Product Brief, which is pretty much the go-to for all detailed information.

    While the web site contains guidance on how to use the wESP32 with different development environments, there is now also a wESP32 demo code repository on Github, which contains full projects to get you started!  At the time of writing it has the iperf Ethernet IDF code I used to get the performance numbers mentioned in my project logs, an ESP32-Arduino example to control a display from a web server, two simple MicroPython examples to control an LED light, one from a web server and one using, and a Mongoose OS demo that allows you to control an LED light very simply from an automatically generated web app!

    If you take a look at these examples, you can see that most of them are quite simple and don't require much code at all.  For instance, here's the LED control from code:

    import machine
    import time
    import urequests
    # Initialize light PWM, flash for 1/4 sec on boot
    led = machine.Pin(23, machine.Pin.OUT)
    ledpwm = machine.PWM(led)
    # Get the ESP32 unique ID as a string
    uid = ''.join(['{:02x}'.format(x) for x in machine.unique_id()])
    # Check every two seconds to get and update the light level
    while True:
        light_level = int(urequests.get(
        print ("Light level {}".format(light_level))

    So if you thought the wESP32 was interesting but would be too hard to get started with, think again!  There are still a couple of days left to change your mind and get your own wESP32 by backing my campaign! :)

  • Crowd Supply campaign now live

    Patrick Van Oosterwijck10/05/2018 at 21:40 0 comments

    The wESP32 Crowd Supply campaign is now live!  I have parts for about 230 units in-house, so if you want one before the end of the year, at the time of writing there are less than 100 of those left!  If you order later, they will ship from a new batch which is scheduled for February 2019.

    As I mentioned in the first campaign update on CS, I received the production PCB panels for the first batch:

    I'm really pleased with how these turned out, my wasp is finally black and yellow as it should be. :)

  • Crowd Supply pre-campaign page live

    Patrick Van Oosterwijck09/05/2018 at 00:17 0 comments

    The wESP32 Crowd Supply pre-campaign page is now live!

    Check it out and sign up if you want to be notified when the campaign goes live!  There will be some early bird specials so signing up may land you a special deal. :)

  • Coming to Crowd Supply!

    Patrick Van Oosterwijck08/31/2018 at 18:43 0 comments

    The wESP32 is coming to Crowd Supply!  After seeing how successful our #LiFePO4wered/Pi+ campaign was, it made sense to repeat the same thing for the wESP32.  I hope to have the campaign up very soon now so you can start ordering!

    I've been very busy the past week with ordering boards, ordering components, and coming up with marketing materials.  A campaign video is in the works, and we need demos to show off some cool stuff you can do with the wESP32.  One simple idea was to make a "remote status display" you can send messages to:

    You'd probably want a bigger screen for the real deal, but is conveys the idea. :)

    @martinschki had a good question in the comments: "How much heat do they emit under a low power application?"  I've been doing tests and taking thermal pictures at high load, but I never thought of doing it for low loads!  And in applications such as his where things get built into a wall this is important.  So here's a thermal image under low load, running the demo shown above:

    So it looks like the hottest thing on the board is the Ethernet phy chip.  At 51°C I don't expect any problems for having it in a wall.  But if you're going to use this to build an environmental sensor, you definitely need to keep this heat in mind when you design your device or your readings will be way off!

  • Final performance checks

    Patrick Van Oosterwijck08/21/2018 at 18:19 0 comments

    I had left off my data performance testing last time wondering why the iperf UDP data rate was so low.  Well, @aenertia on Twitter gave me a hint: you need to specify the amount of bandwidth you want to test on the client side, otherwise the UDP test defaults to 1 Mbit/s!  So, just an average case of operator error. :)  The iperf on ESP32 example code is too simple and doesn't provide / need this option, and I haven't played enough with this kind of stuff before to know things like that.

    Here are the results for UDP when the wESP32 is the client (outgoing traffic):

    Around 70 Mbit /s, nice!

    So to test server, I used the following command on the client:

    iperf -c -i 3 -t 60 -u -b 100m

     This sets the target bendwidth to 100 MBit/s.

    Here are the results for UDP when the wESP32 is the server (incoming traffic):

    Wow, >90 Mbit/s!  That's close to the theoretical maximum!

    Now I'm pretty sure that from the moment the ESP32 would start to do anything with this data other than throw it away, the data rate would go down, but it's still nice to see that the Ethernet data system as implemented on the wESP32 performs very well.

    One last thing left on my list to validate the design was to test power performance when the 5V power option is selected by bridging the solder jumper.  As mentioned before, the whole power system is optimized for 12V power, and the 5V option was a little bit of an afterthought but it could be useful to many people.  So how does it do?

    In my first test I was really pushing it:

    Trying to push >2A through a power path that was designed for 1A: not a good idea.  That poor diode was frying, but it lived.  So, intermittent 10W may be possible at 5V, but don't run it like this continuously.

    Here's a more moderate test:

    That's better.  At 6W output (1.2A), the diode temperature isn't so bad.  Still, when running at 5V, your continuous average load should probably be kept below 5W.

    These results are fine though.  If you need high power, use 12V.  It keeps the currents much more reasonable.  If you really need high power at 5V, add your own buck converter.  The on-board option for 5V will likely still be very useful for the majority of people who need 5V in their system though.  5V sensors, keypads, displays, etc. usually don't need that much power.

View all 24 project logs

Enjoy this project?



Mikhail wrote 08/21/2018 at 07:47 point

Thanks for your great project, Patrick!


Personally I don't like ESP32-WROOM module and do prefer ESP32-PICO-D4  with a 3D antenna for better Wi-Fi connection and lower overall power consumption, but it will make a board a lot more complicated, so that's not an real issue now for PoE solution, just a wish.


As I see now your project is close to prototype completion, so any estimates now for release date and production costs for small quantities? (~100pcs batches after initial evaluation) 

  Are you sure? yes | no

Patrick Van Oosterwijck wrote 08/21/2018 at 17:41 point

I use the ESP32-WROOM because it has modular FCC certification, which I wouldn't get if I did my own antenna.  Likely the WiFi won't be used on this board in most cases, but I am interested in the Bluetooth functionality as it can make this a useful Bluetooth sensor aggregator / hub.

I have parts for a 240 piece batch on order, and am talking to Crowd Supply to do another campaign like the one I'm running for the #LiFePO4wered/Pi+ right now (

  Are you sure? yes | no

Mikhail wrote 08/21/2018 at 21:41 point

Don't really care about certification - still need to recertify everything for production devices, at least where I am (Russia).

OK, count on me as very interested for samples and maybe larger quantities. It will depend on price and performance vs our current prototypes that are made using  PoE splitter and Ethernet module add-ons.

Personally I do like using Bluetooth for connecting speakers to ESP32. (just sharing an idea)

  Are you sure? yes | no

John wrote 08/21/2018 at 07:13 point

This is really awesome, Patrick! I am looking forward to get a few of these boards when they are available!  I'm trying to learn more about how PoE works and was wondering why you decided to use a RJ45 jack with a bridge rectifier and an external transformer over an RJ45 jack with a built in transformer and an external bridge rectifier. Excuse my noob-question on this. Still at baby steps in understanding PoE. Thanks

  Are you sure? yes | no

Patrick Van Oosterwijck wrote 08/21/2018 at 17:35 point

Thanks John!  The RJ45 jack does contain the Ethernet magnetics ("transformers") for the data path.  The external transformer is for PoE power conversion only, and as far as I'm aware, nobody produces an RJ45 jack with this power transformer integrated.  It wouldn't make sense to do this since a lot of circuitry is involved (all the circuitry between the RJ45 and flyback transformer).

The jack I use integrates the PoE diode bridges in addition to the Ethernet magnetics, which is nice because these bridges tend to take up a lot of PCB space.

  Are you sure? yes | no

John wrote 08/22/2018 at 13:53 point

Thanks for the reply. Ah! Now I understand. I got confused about the power transformer and thought this was the ethernet magnetics.

Follow up question on ethernet jacks. Did I get this correct that the jack you use uses all 4 pairs for power, and two pairs are data? If so, the PHY only uses one pair for data? I am trying to understand how some hobbyists may just split open an RJ45 cable and add 12v to it, and what that might result in. Sorry again for the noob-question.

  Are you sure? yes | no

Patrick Van Oosterwijck wrote 08/22/2018 at 16:42 point

The phy uses two pairs for data.  For IEEE 802.3at compliant PoE, the power can either be on the same pairs as the data, or it can be on the spare pairs, so the Ethernet jack contains two diode bridges to cover both cases.

The DIY 12V or "passive PoE" are not standard compliant and not supported by the wESP32.

  Are you sure? yes | no

Prof. Fartsparkle wrote 08/19/2018 at 22:22 point

Great stuff! I really miss Ethernet with all these modern MCUs, even if they support it natively, barely anyone makes boards that support it.
Will you sell it afterwards? This would definitely be interesting for some work projects.

  Are you sure? yes | no

Patrick Van Oosterwijck wrote 08/20/2018 at 05:24 point

Yes!  As all major systems have been checked out and I'm very satisfied with the performance of the design, getting to production is being worked on right now! :)

  Are you sure? yes | no

Prof. Fartsparkle wrote 08/20/2018 at 12:22 point

Great! Do you have a price target yet?

  Are you sure? yes | no


[this comment has been deleted]

Patrick Van Oosterwijck wrote 08/20/2018 at 05:23 point

I moved it to the other side of the bead to make my layout easier. :)

Would it be "better" if this connection was on the other side of the bead?  Maybe.  Then you have to define "better".  Is the bead there to give the Ethernet signal path a cleaner power source, or to prevent switching noise from the Ethernet to get back to the 3V supply?  I don't know which they had in mind, probably both.  In the end, engineering is about compromises, and I would have had difficulties with my layout had I made these connections after the bead, so I decided to connect them to 3.3V instead.

The proof is in the pudding as they say and in this case "better" is probably just a matter of performance.  With 63 Mbit/s up and 55 Mbit/s down, I'm perfectly happy with the performance as it is. :)

  Are you sure? yes | no

K.C. Lee wrote 08/20/2018 at 12:59 point

You want to prevent digital noise getting into a long piece of Ethernet cable which can act as an antenna to the outside world.  i.e. keep the power clean at the Ethernet side.  So a LC filter would have the caps etc at the receiving side of the bead,  At least that's the way I would do it even if it means that I have to rip up all my nets and do another rounds of routing.  I don't settle at something that "works".

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Patrick Van Oosterwijck wrote 08/20/2018 at 17:03 point

I agree 100%, but please check in the schematic what he's talking about first.  He's talking about the supply to the center taps of the secondary side signal transformers.

The power system connected to the primary (cable) side does have the recommended filter circuitry at the input (L3, L5, C26, C27).

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SK wrote 07/29/2018 at 11:33 point

Hey there, very interesting project.
Olimex recently announced a similar board - ESP32-POE. There is no confirmation yet, but I am guessing they will release it as an OSHW design (all their other ESP32 boards are OSHW):

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Patrick Van Oosterwijck wrote 08/16/2018 at 20:09 point

Yeah, I saw that, and at first I thought: "With competition from such a known player I might as well shelve this project".  But then I looked at the info that was available and noticed:

- There's no flyback transformer which means their design provides no isolation as required by the IEEE 802.3af/at PoE specification.  Prototyping will be fine but actual installations with long wire runs in buildings will likely be troublesome.

- I haven't seen any specification on available output power.  The size of the inductor makes me think 12.95W as specified for IEEE 802.3at Type 1 is not attainable.

- It uses the CH340 for programming which is really undesirable.  My friend's Macbook got bricked by trying to install the driver for this device.

All of this (especially the first point) puts their device firmly in the hobbyist category.  I'm under no illusion that this still represents stiff competition as their price will be better than mine and most people will hear about theirs and not mine, but I'm hoping there will be a niche for me when people are looking at professional deployments that are IEEE 802.3at compliant.

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hennie.tempelman wrote 07/07/2018 at 21:22 point

Hi Patrick, really great project.

For years I have been using the Propox Wiznet module with ATMEGA128A and Ethernet. Very much like the AVR-Studio. I work in industrial automation (gas turbines); I even implemented the Siemens S7 protocol on my AVR and now can do great stuff such as native peer comms and talking to a DDE/OPC server. This gives me great 'eyes' to my projects.

But time moves on. Got myself an ARM board (Atmel SAM D20) because everybody says you should be 32 bit; with this I would be able to use Studio for that too. But I couldn't really see the benefit of moving to 32 bit 'just because', so it grinded to a halt.

Then recently I did get kind of stuck. I want to make a weather station (based on a recent Elektor design), but with my good-old Wiznet. But pulling yet another Ethernet cable... A Wifi add-on for the ATMEGA seems expensive and clumsy. And the ESP32 has it all out of the box, and so much more. And oh-yes, it is 32 bit and amazing clock speeds - thus future proof. And cheap.

But... Wifi is fine for a weather station. But not for important stuff such as domotics, machine automation and what else. But with the standard ESP32 solutions on the market I was now loosing my Ethernet. Except for some poor Olimex designs (too bulky for integration).

Then I found your project. I think it is almost perfect, and I totally agree with all your considerations. I think the initial price you have in mind is just fine; I pay a similar price for the Propox module and that never stopped me.

So when you have some for sale; I'd be happy to buy a few to try and use in my next projects.

I have a question: Can the module also be powered WITHOUT POE? (i.e. will it merrily accept 3.3 V or 5 V on the power pins?) I guess yes, but asking to be sure.

I also have another question (to you or others): would I be able to use my favoured AVR-Studio still with an ESP32 signature file or so? If not, what similar environment would you recommend. Whilst I do a lot with AVRs, I never had a go at Arduinos (and don't really want to either), so I am not familiar with that environment .

And 'if' you consider a redesign, then I'd suggest to make a DIP-style pinning. This is easier for use on a breadboard (as double pin rows cause a short). And on a final product you achieve mounting stability without any need for screws and such. Just check the Propox module (and others) as example.

Thanks - Hennie.

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Patrick Van Oosterwijck wrote 07/28/2018 at 03:15 point

Hello Hennie,

Thanks for your kind words! :)  Here are some answers to your questions:

- Yes, you can supply power to the V+ pin or, if the ESP32-Prog module is installed, it can power the ESP32 over USB.

- I have no idea if you can program an ESP32 from AVR Studio, I would assume not but I don't know how flexible it is.  Not a fan of Arduino myself, I consider it yesterday's cool way of doing things and behind the times.  For C you can do ESP-IDF and MongooseOS, Espruino and MicroPython work well too for higher level development.  PlatformIO provides a nice environment as well.  Anything's better than Arduino. ;)

- DIP-style: I was considering this at some point but someone else said dual row header was what they preferred and it was the only feedback I got at the time.  In hindsight, it was the better option as well to be able to do the really dense layout to keep it small.  There are ribbon cable header to breadboard adapters in the market that should work.  I agree prototyping concerns are important, and there should be solutions provided even if they take some extra parts, but this project is mostly production optimized for people who want to use it in the field.

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Giovanni wrote 06/10/2018 at 23:27 point

Hi Patrick, great project! 

Quick question - will there be 5V available from the board along with 3.3V for powering external components? That would be very handy!

BTW Did you think of starting a small Kickstarter or Indiegogo campaign? I know this is quite a niche project so perhaps the audience will be limited but on the other hand you may not need that much money to complete it either.

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Patrick Van Oosterwijck wrote 06/11/2018 at 11:23 point

By default there is 12V and 3.3V available.  But I included a solder jumper to switch from 12V to 5V on the power output.  Total output power will likely be less when configured to 5V compared to 12V since the flyback turns ratio is optimized for 12V.  You can of course do your own conversion from 12V to 5V as well.

Doing a campaign is definitely on the table.  First need to confirm everything works though. :)

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Andreas wrote 05/26/2018 at 09:25 point

Hi Patrick, - I like your thoughts on PoE with ESP32 because I am looking for a way to replace a working door lock system for 30 doors in one building that I designed in about 2008 (together with an EE) that still works well but so far, it's a prototype. Technology has moved on since then.

I am choosing the ESP32 now because it seems to be the only small, affordable microcontroller out there capable of a decent encryption (AES etc.). Wifi does not make sense for me because it can be blocked and might be unreliable. What I'd need as an adaption of the WESP32 that connects a numerical keyboard (we can manufacture that here, inox steel for outside), three LEDs and a relay to open a door opener magnet. The 12 V version of PoE seems fine to me, but I'd have more questions. Would you be available for some questions? I could not find an email address so far. My website is and I am thinking of sponsoring your development of the WESP32 if this is still on the table :) - and then we could talk about paid modifications..


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Patrick Van Oosterwijck wrote 06/11/2018 at 09:57 point

Hello Andreas,

Sorry I didn't see this sooner, seems to be very flaky about sending comment notifications.  Sometimes it does, sometimes it doesn't.  I haven't found any logic in it yet.

Your application looks perfect for something like this!  We can discuss your questions over email and I am certainly interested in your sponsoring offer! :)  I'll shoot you an email.


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bbz wrote 05/18/2018 at 20:33 point

You mention the prize funding a lot, how much is it? I would have thought there'd be enough interest in this to cover it.

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Patrick Van Oosterwijck wrote 05/21/2018 at 04:16 point

I think once it's ready to sell, I'll be OK, but getting there would have been easier/quicker with the Hackaday funding ($1000), that's all.  Instead of having funds to live off while I work on this and pay for prototypes etc, I have to work on other (paying) projects to live off and fund the prototypes, so getting this to market will be slower.

Plus more eyeballs of course when you're a finalist.  You can have a great project but if no one knows about it, it won't sell enough to matter.  Having people find out about your product is always the biggest hurdle to overcome.

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kesh27 wrote 05/14/2018 at 20:44 point

Looking forward to a prototype. This would make a great little data closet monitor with something like a BME280 sensor.

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Netoperz wrote 05/12/2018 at 16:42 point

There is one most important thing ever , level shifters.

I have build a automation system for building on esp32 and it is working over year now, i have used many type of boards from many brands, and i have made some my own designs.

There always you face 3 problems

1. power supply (solved here as it is POE)

3. interfaces to the external modules/devices and those never use 3,3v ttl level, most automation things use 5v (keypads, locks readers...) so there always  is a must to add additional level shifter (nad this solution does not solve the problem)

4. size - in most cases you would like to put that board in the wall mount (just lunder the power socket or switch, or just in that hole as it is esy to buy them and put on building project to make them)

So if this board want's to be something "new" it must have POE and level shifting, board should have uSD card socket for storage, it is better for firmware updates or database processing.

I would say that OLIMEX

have made the perfect one, but it lacks poe and level shifting.

If you will make something like that but with poe and level shifting you may sell them a lot, i would order a few hundreds for my projects.

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Patrick Van Oosterwijck wrote 05/18/2018 at 15:09 point

Hi, thanks for your comment!

I disagree on integrating level shifters on a generic core board like this though.  Sure, _your_ application needs them, but there are many that don't.  Most new environmental sensors are 3.3V, just ask all the people still stuck in 5V Arduino land that need to level shift day and night.  If the I/O signals were level shifted to 5V by default, many people would have to level shift back to 3.3V, which would be silly of course.  I consider level shifters firmly in the "application specific" realm.  You likely need specific connectors for your keypad, lock reader etc, anyway.  So if you use something like this, your level shifters can be on a little add-on PCB that converts from the generic ESP32 I/O header to your application specific connectors.  Selectable 5V or 12V is available on the I/O header to make this easy.

The current size would fit in a wall mount I think (75 x 40mm).  If your application specific adapter board folds back over the ESP32 area, you can have a nice compact solution since it would sit next to the tall components on the other end of the wESP32 board.

I though about integrating an SD card slot but decided against it.  The SD card is considered application specific as well, but I made sure to have all the needed I/Os available on the header as I understand it would be of interest to many people.  It would have taken up a ton of space and made the board significantly larger though, so I favoured size.

I'm happy with this being something "new" as it is, since I don't think there are any PoE ESP32 boards on the market, and definitely not any there are this small.

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icodk wrote 05/24/2018 at 16:08 point

I agree with your priorities. Keep it as generic as possible

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Prakhar Birla wrote 05/04/2018 at 02:56 point

Great project! I hope you get the prototypes this month. 

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bbz wrote 04/20/2018 at 20:30 point

making good progress

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hackadoy wrote 04/10/2018 at 07:46 point

Great project. Is there any planned launch date?

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Patrick Van Oosterwijck wrote 04/10/2018 at 14:30 point

No, I have too many other projects at the moment to be able to dedicate a firm amount of time on it.  That said, it's my favorite "distraction" at the moment, so I'm making decent progress.  I expect to have prototypes in the next month or two.

Stay tuned! :)

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Patrick Van Oosterwijck wrote 03/30/2018 at 23:10 point

Thanks for the input everyone, very useful! :)  It may be hard to fulfil everyone's wishes, but I'll try to keep all your comments in mind!

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Ashton Smith wrote 03/26/2018 at 23:07 point

Do this! ive been looking for basically exactly this, and i was going to try to use the PoEPi project ( but this would be perfect - im afraid i cant provide much help, but i would buy for sure!

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bbz wrote 03/26/2018 at 13:13 point

I've been using the olimex boards for development and considering making a board like you describe for production use. Other than lacking PoE and being not small enough for my use they are great.

External PoE is cheap (like ) so to make a new board worth while it'd need to be better than that combination. Passive PoE is not worth bothering with, people can do that themselves trivially

I aim to build this board into things for monitoring and control. I prefer wired over wireless as they will be hard to access and I don't want to be swapping batteries on loads of them, wireless is also too unreliable for control applications (and adds security/electrical interference risk). With PoE I can remotely reset any unresponsive device.

My ideal form factor is to have it built in the ethernet jack like and Both those are too expensive, lack i/o and lack PoE. Sadly ESP32 lack ethernet PHY otherwise building it in an oversized jack might work.

Things I'd be looking for in a board -

Ideal size is not larger than a match box, approx 45 x 30 x 15 mm if can't fit in ethernet jack

Active PoE, I value size over price so the extra cost of a lower power profile than 12W is fine, I see you are going for 12W on cost, perhaps a smaller low power version later.

I'm using ethernet not wireless so not worried about compliance, thus can use the pico chip directly for smallest size instead of the larger complaint modules. One exception is that for door readers I want to use the BT but could use a different board there.

I'd like to add specialist i/o around it so option to stack a small board replacing direct i/o. For most cases we'd have direct i/o like (I use these devices but they aren't open to adding your own code, I want our code to feed into MQTT)

A space for a dc/dc convertor to power external things (like smoke detectors, PIRs, door locks) would be great, there are small ones that could be installed as needed like - which are available in a range of voltages and power. If you're making your own PoE converter then it may be better to feed this converter upstream of the output or even incorporate it. The plan is for most cases not to need an external supply. For larger things we can use pass through PoE splitters that will take 60W, provide DC out and onward PoE for this board (hence not wanting this board to signal than it needs 12W when it only needs 3).

I don't have a need for a usb serial programming interface, it wastes space and is only needed on dev boards. An external one is fine for initial load but after that it'll be OTA updates.

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Patrick Van Oosterwijck wrote 03/30/2018 at 23:21 point

I'm afraid I won't be able to make it quite as small as you wish.  I'm aiming for small (always!), but there are limits as to how small you can get with PoE.  A quick calculation shows that just the Ethernet jack, flyback transformer, ESP-WROOM-32 module and IO header take around 11.4 cm^2 by themselves.  That has eaten up the majority of the 13.5 cm^2 you're looking for. :)

For the "general purpose" first version, I'm aiming for 12W, with WiFi and BLE ability as well as there are certain use cases for this.  To get it tiny, I'd have to go for 3W with a ESP32-PICO-D4 without antenna instead.  I may do something like that in the future if I see enough demand.

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bbz wrote 03/31/2018 at 21:35 point

Yes, see how the 12W version goes, I may later commission you to do a smaller 3W version more as I described

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Tom Bull wrote 03/26/2018 at 11:24 point

Would love to help out with this. I've been starting to do something very similar - but I'd like to seriously reduce the cost (flyback transformer, PoE MagJack, etc). I'm currently based in Shenzhen - so if there's anywhere that the cost can be reduced, it's here. Let's talk!

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cata2109 wrote 03/20/2018 at 21:07 point

Smart Wall switch. 

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Chris wrote 03/20/2018 at 18:47 point

Awesome projet. A few usages I can think of:
- Combined with a display, it could be used to create a network diagnostic tool.
- With 5V/12V output it could power a GPS and serve as a ntp server. The ethernet connection would be faster/more reliable than wifi.
- Again with 12V output, it could be used to power a lot of small appliances (router/wifi access point/radio/baby monitor/led strips). The ESP could monitor or talk to the device. Add a relay and it could switch the device on/off.
- A network speaker to play music. Use the PoE for the amplifier and the esp's bluetooth to act as a wireless speaker.
- It could be used to control multiple servos/sensors somewhere you can reach with an ethernet cable but wifi and/or power isn't available (outside or industrial environment).

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