# Use a POE switch to power ESP32 wired

**URL:** <https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696>\
**Category:** Hardware\
**Created:** [20 February 2022 14:56 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696 "2022-02-20T14:56:38Z")\
**Posts on this page:** 20\
**Page:** 1

<div class="post-metadata">

**Author:** ![BartButenaers](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bartbutenaers/32/10476_2.png) [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Post date:** [20 February 2022 14:56 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/1 "2022-02-20T14:56:38Z")

</div>

Hi folks,

@dynamicdave and @zenofmud have been helping me tremendously to get up and running with EspEasy on Wemo D1 mini devices 🙏

So I have a couple of those running already via WIFI. Works very nice! But now I need to install a couple of sensors in my garden (and in underground vessels) where I don't have wifi. And I also don't have any mains plugs in the neighbourhood.

To solve this, I have installed EspEasy on a [wt32-eth01](https://discourse.nodered.org/t/wired-esp32-ethernet/51811) and now I can read an ultrasonic distance sensor via ethernet 🍾

Two years ago I have been digging a tube into the ground, containing a waterproof ethernet cable. So now I would like to connect my wt32-eth01 to that cable. But since I have to power both the wt32-etho01 and the ultrasonic sensor, I would like to use power over ethernet (POE) to avoid having to install an extra power cable, and to avoid needing to install row of power adapters in my house. A poe switch is a very compact and neat solution...

I was thinking of this approach (since the wt32-eth01 doesn't support POE):

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/9/a/9a91193fc3005c85c6dd2e1af110c10a7c1dacce.jpeg)

1. So first I would like to buy [this](https://www.amazon.com/dp/B082KM1796?pd_rd_i=B082KM1796&pd_rd_w=ukDEk&pf_rd_p=7a328fa7-ad0a-4415-90da-0e32a7710f67&pd_rd_wg=ewh5Y&pf_rd_r=N9VK39JRNWA3M1ZC4AQH&pd_rd_r=3353d777-8ca6-4833-8cf4-66f8d118ffdb) affordable POE switch. It is only 100Mbit, but that is enough for my use case (i.e. read a sensor periodically). If I understood it correctly, this switch delivers 48Volt, with a total maximum of 120Watt (and maximum 30W on a single port).

2. A POE [splitter](https://nl.aliexpress.com/item/1005001344857403.html?spm=a2g0o.productlist.0.0.4ff414f4AHzbwj&algo_pvid=967568a6-c1a3-483d-a0e6-f99ccb0a4073&algo_exp_id=967568a6-c1a3-483d-a0e6-f99ccb0a4073-1&pdp_ext_f=%7B%22sku_id%22%3A%2212000015764203320%22%7D&pdp_pi=-1%3B2.03%3B-1%3B-1%40salePrice%3BUSD%3Bsearch-mainSearch) cable, to separate the DC voltage apart from the ethernet signal.

3. A step down [converter](https://nl.aliexpress.com/item/1005003895191855.html?spm=a2g0o.productlist.0.0.538d7481CsmoYb&algo_pvid=947d8f1e-7512-446e-a2b5-ab0dc6c9ee9d&algo_exp_id=947d8f1e-7512-446e-a2b5-ab0dc6c9ee9d-26&pdp_ext_f=%7B%22sku_id%22%3A%2212000027409136001%22%7D&pdp_pi=-1%3B3.43%3B-1%3B-1%40salePrice%3BUSD%3Bsearch-mainSearch), to convert 48V to 5V (to power the wt32-eth01 and the jsn-sr04t)

4. A [fuse](https://nl.aliexpress.com/item/1005001382349173.html?spm=a2g0o.productlist.0.0.722f4713rWgNv1&algo_pvid=222a0f05-2937-4a35-893d-2c8b825d7fbe&aem_p4p_detail=202202201225195297540968650960179332432&algo_exp_id=222a0f05-2937-4a35-893d-2c8b825d7fbe-9&pdp_ext_f=%7B%22sku_id%22%3A%2212000015876657907%22%7D&pdp_pi=-1%3B5.23%3B-1%3B35%40salePrice%3BUSD%3Bsearch-mainSearch) is added, in case e.g. a shovel breaks the cable (introducing a short circuit).

Does anybody sees things I have overlooked in this solution, or things I should take into acount?

Thanks !!!  
Bart

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<div class="post-metadata">

**Author:** ![Sean-McG](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/sean-mcg/32/54677_2.png) [@Sean-McG](https://discourse.nodered.org/u/Sean-McG)\
**Post date:** [20 February 2022 15:37 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/2 "2022-02-20T15:37:47Z")

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Looking good - I assume it will be in an suitable box (IP rated). Don't want to start another battle but you could include fuse(s) at the the converter 😉

I see you went over to the dark side (EspEasy ) - not Tasmota 🤪

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<div class="post-metadata">

**Author:** ![ghayne](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ghayne/32/39_2.png) [@ghayne](https://discourse.nodered.org/u/ghayne)\
**Post date:** [20 February 2022 15:37 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/3 "2022-02-20T15:37:52Z")

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> [@BartButenaers](#):
>
> the wt32-eth01 and the jsn-sr04t

Bart, do these use the same logic levels?

[EDIT] The jsn-sr04t is TTL (5v) and the wt32-eth01 can use 5v or 3.3v on the serial inputs.  
Looks good!

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<div class="post-metadata">

**Author:** ![greengolfer](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/greengolfer/32/28276_2.png) [@greengolfer](https://discourse.nodered.org/u/greengolfer)\
**Post date:** [20 February 2022 15:54 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/4 "2022-02-20T15:54:17Z")

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A POE ready ESP32 exists: [ESP32-POE - Open Source Hardware Board](https://www.olimex.com/Products/IoT/ESP32/ESP32-POE/open-source-hardware)  
It may make the installation more robust: avoid the splitter, avoid the converter.  
And it is working with ESP-HOME too...  
Never tried those, however.

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<div class="post-metadata">

**Author:** ![TotallyInformation](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/totallyinformation/32/31_2.png) [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)\
**Post date:** [20 February 2022 17:51 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/5 "2022-02-20T17:51:23Z")

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> [@BartButenaers](#):
>
> Does anybody sees things I have overlooked in this solutio

I guess the only other thing to think about would be lightning - a strike near a long cable, even if buried, might cause quite a mess of your switch and the devices. 🌩

I'm not an expert so I couldn't say what might be needed to protect from that or even whether it is a realistic issue.

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<div class="post-metadata">

**Author:** ![LosinIt](https://avatars.discourse-cdn.com/v4/letter/l/439d5e/32.png) [@LosinIt](https://discourse.nodered.org/u/LosinIt)\
**Post date:** [20 February 2022 18:31 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/6 "2022-02-20T18:31:37Z")

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Having had a strike on a tree in front of my house in '97 I can tell you that you're probably not safe within 50 yards. I lost a in/outdoor temp unit, a RS232 chip on a board with a cable attached only on one end, a light bulb in the basement, and a circuit breaker tripped but wasn't damaged. A neighbor about 50 yards away lost a microwave oven and in the other direction a guy lost his weather station.

Even with that I'd go ahead, @BartButenaers, as the risk is not that great unless you're in a very frequent lightening area and have had near strikes before.

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<div class="post-metadata">

**Author:** ![BartButenaers](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bartbutenaers/32/10476_2.png) [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Post date:** [20 February 2022 21:04 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/7 "2022-02-20T21:04:44Z")

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> [@Sean-McG](#):
>
> you could include fuse(s) at the the converter

Hey @Sean-McG,  
I have added it to my original post now. Although now I re-read your sentence and I see you write 'at the converter' while I have added it at the side of the poe switch...

> [@greengolfer](#):
>
> A POE ready ESP32 exists: [ESP32-POE - Open Source Hardware Board](https://www.olimex.com/Products/IoT/ESP32/ESP32-POE/open-source-hardware)  
> It may make the installation more robust: avoid the splitter, avoid the converter.

I have taken that board into consideration last year, but it was quite expensive compared to the wt32-eth01. But indeed then the splitter can be avoided. However I don't think the converter can be avoided, because you need to convert the voltage to 5V.

> [@TotallyInformation](#):
>
> I guess the only other thing to think about would be lightning

Hey Julian,  
Yes that is true. But I have now arrived at a point that I need to exclude such riscs from my list, otherwise I will never live the day that I have any sensors running 😉

> [@Sean-McG](#):
>
> I see you went over to the dark side (EspEasy ) - not Tasmota

The main reason why I started with EspEasy is that it supported the wt32-eth01 out of the box. While Tasmota required an unofficial build (if I understood correctly). And I wanted to have the same firmware on all my devices (wifi and ethernet), to keep my setup as simple as possible. But it could have been that Tasmota was even better for my purpose. But currently EspEasy fullfills my needs...

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<div class="post-metadata">

**Author:** ![craigcurtin](https://avatars.discourse-cdn.com/v4/letter/c/94ad74/32.png) [@craigcurtin](https://discourse.nodered.org/u/craigcurtin)\
**Post date:** [21 February 2022 01:24 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/8 "2022-02-21T01:24:08Z")

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Bart,

Just one thing (and taking into account other posts of yours) i would not go for a 100MB switch - you have recently raised questions re IP cameras - most of which you would want to do as POE and ethernet - 100MB/s will not then cut it for multiple cameras at high frame rates or with multiple streams.

Moving to a Gigabit switch with POE is not that much more expensive

Craig

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<div class="post-metadata">

**Author:** ![DonBurch](https://avatars.discourse-cdn.com/v4/letter/d/e274bd/32.png) [@DonBurch](https://discourse.nodered.org/u/DonBurch)\
**Post date:** [21 February 2022 02:42 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/9 "2022-02-21T02:42:27Z")

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> [@BartButenaers](#):
>
> But indeed then the splitter can be avoided. However I don't think the converter can be avoided, because you need to convert the voltage to 5V.

If you are plugging the ethernet cable directly into the ESP32-POE (which is the reason for using a POE model) then the ESP device is already converting voltage down to whatever the rest of the board requires.

However, be aware there is a physical limit to the amount of 5V current available to the POE-powered ESP32-POE and attached devices. From the FAQ for the ESP32-POE board linked to above:

```auto
Q) What current is available when the board is powered via the Ethernet connector (PoE)?
A) The PoE circuit can safely provide up to 4W, i.e. 800mA @ 5V. Part of this wattage is used to power the ESP32 module, the battery charger, and other circuits part of the board design; the remaining wattage is available for additional circuits (up to around 600mA). Make sure the total current consumption does not exceed 800mA @ 5V.

```

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<div class="post-metadata">

**Author:** ![Sean-McG](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/sean-mcg/32/54677_2.png) [@Sean-McG](https://discourse.nodered.org/u/Sean-McG)\
**Post date:** [21 February 2022 16:41 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/10 "2022-02-21T16:41:18Z")

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Same price for the gig version - [YuanLey-Gigabit](https://www.amazon.com/YuanLey-Gigabit-1000Mbps-802-3af-Unmanaged-dp-B082D9FWQH/dp/B082D9FWQH/ref=dp_ob_title_ce)

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<div class="post-metadata">

**Author:** ![BartButenaers](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bartbutenaers/32/10476_2.png) [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Post date:** [21 February 2022 20:31 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/11 "2022-02-21T20:31:49Z")

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> [@craigcurtin](#):
>
> taking into account other posts of yours

Hey Craig,  
Good that I write down on Discourse all my personal plans, because then people like you can remind me about it afterwards 😉 . Good one! Especially since @Sean-McG found below a Gig version...

> [@DonBurch](#):
>
> If you are plugging the ethernet cable directly into the ESP32-POE (which is the reason for using a POE model) then the ESP device is already converting voltage down to whatever the rest of the board requires.

Hey @DonBurch,  
Welcome to discourse!! You got my attention already immediately on your first visit 👍  
Very stupid of me, but I hadn't thought about the fact that an ESP32-POE can be connected directly to an 48V POE switch.  
And the physical limit section is also very good information.  
Thanks !!!

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<div class="post-metadata">

**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [22 February 2022 08:25 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/12 "2022-02-22T08:25:00Z")

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Bart,  
While the esp-poe is probably the right answer you can also get prebuilt down convertors to microusb connector style like - [https://www.amazon.co.uk/DSLRKIT-Active-Splitter-Ethernet-Raspberry/dp/B01H37XQP8/ref=asc\_df\_B01H37XQP8/?tag=googshopuk-21&linkCode=df0&hvadid=310876754081&hvpos=&hvnetw=g&hvrand=15646841136010649894&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1007237&hvtargid=pla-560965433456&psc=1](https://www.amazon.co.uk/DSLRKIT-Active-Splitter-Ethernet-Raspberry/dp/B01H37XQP8/ref=asc_df_B01H37XQP8/?tag=googshopuk-21&linkCode=df0&hvadid=310876754081&hvpos=&hvnetw=g&hvrand=15646841136010649894&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1007237&hvtargid=pla-560965433456&psc=1)

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<div class="post-metadata">

**Author:** ![ghayne](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ghayne/32/39_2.png) [@ghayne](https://discourse.nodered.org/u/ghayne)\
**Post date:** [22 February 2022 09:20 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/13 "2022-02-22T09:20:42Z")

</div>

> [@dceejay](#):
>
> you can also get prebuilt down convertors to microusb connector style like

Serendipity! That is just the thing I need for an idea I have. Cheers Dave!

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<div class="post-metadata">

**Author:** ![BartButenaers](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bartbutenaers/32/10476_2.png) [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Post date:** [22 February 2022 11:15 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/14 "2022-02-22T11:15:15Z")

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> [@dceejay](#):
>
> While the esp-poe is probably the right answer you can also get prebuilt down convertors to microusb connector

Hey Dave,  
That is indeed better, to make the setup smaller, because one component less.

However a wt32-eth01 does _not_ (unlike e.g. a wemo d1 mini board) have a micro-usb connector unfortunately...

I had to install the firmware on it via a usb-to-serial flasher, because it does not have a micro-usb interface...

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<div class="post-metadata">

**Author:** ![BartButenaers](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bartbutenaers/32/10476_2.png) [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Post date:** [22 February 2022 11:25 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/15 "2022-02-22T11:25:19Z")

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If I could find [these](https://www.amazon.nl/-/en/dp/B085ZH2W21/ref=sr_1_12?crid=3C59NKFM48VQI&keywords=poe+splitter+converter+48v+5v&qid=1645528988&sprefix=poe+splitter+converter+48v+5v%2Caps%2C71&sr=8-12) but with 5V instead of 12V, that would do the job I think...

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<div class="post-metadata">

**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [22 February 2022 11:40 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/16 "2022-02-22T11:40:47Z")

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Well you can get pure passive ones instead - then use whatever voltage supply you like rather than a POE switch...

> **[HSEAMALL 1 Pair Passive Power over Ethernet RJ45 PoE Adapter Injector + Splitter...](https://www.amazon.co.uk/HSeaMall-Passive-Ethernet-Injector-Splitter/dp/B076LWCLN2)**
>
> The complete Passive Power over Ethernet SET contains two pieces - INJECTOR and SPLITTER. It is suitable for using with products IP camera are with the smaller size power jack.   Specifications: Color: Black Material:...

Or indeed just cut off the micro USB as that module doesn't seem to have any power connector at all - so either you wire up something or go direct to the board anyway.

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<div class="post-metadata">

**Author:** ![Sean-McG](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/sean-mcg/32/54677_2.png) [@Sean-McG](https://discourse.nodered.org/u/Sean-McG)\
**Post date:** [22 February 2022 12:28 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/17 "2022-02-22T12:28:23Z")

</div>

> [@dceejay](#):
>
> just cut off the micro USB

Sounds like a plan 😉  
Then you can add an inline fuse before the ESP and sensors, given this can output 2.4A

---

<div class="post-metadata">

**Author:** ![BartButenaers](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bartbutenaers/32/10476_2.png) [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Post date:** [22 February 2022 19:00 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/18 "2022-02-22T19:00:58Z")

</div>

> [@dceejay](#):
>
> then use whatever voltage supply you like rather than a POE switch...

Yes that was my first idea. But then I need POE splitters on one side and POE injectors on the other side. And then I need multiple power supplies, and I also need step-down converters because 5V on a longer cable is not optimal...  
So therefore a POE switch is a very neat solution, because it is nicely all within one box and you just need to insert your cat cables.

> [@dceejay](#):
>
> just cut off the micro USB

When you shared your link today of the converters, that popped also in my mind. But to be honest I always feel bad when I need to start cutting in nicely fabricated stuff that I just bought. Then I always think: perhaps this is not my best idea ever 😉

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<div class="post-metadata">

**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [22 February 2022 19:49 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/19 "2022-02-22T19:49:18Z")

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Of course you can compensate for a long cable with a higher voltage input to allow for the drop.

But yes cutting new stuff always irks me. But soldering two wires to connect it to the board is easier than wiring up a micro usb socket just so you keep the plug. And the whole thing is only 3 decent coffee or 2 beers.

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<div class="post-metadata">

**Author:** ![BartButenaers](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bartbutenaers/32/10476_2.png) [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Post date:** [22 February 2022 20:07 UTC](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696/20 "2022-02-22T20:07:36Z")

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Found an active POE splitter that got my attention ([here](https://nl.aliexpress.com/item/1005001356576287.html?spm=a2g0o.productlist.0.0.4a241cc0Cd7G7L&algo_pvid=102abff7-cf5f-40b5-8e11-9b1ce7ac0439&algo_exp_id=102abff7-cf5f-40b5-8e11-9b1ce7ac0439-1&pdp_ext_f=%7B%22sku_id%22%3A%2212000015796991602%22%7D&pdp_pi=-1%3B4.5%3B-1%3B91%40salePrice%3BUSD%3Bsearch-mainSearch) on Ali):

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/6/a/6aaf9809d227799ed8e09778aa398b66756d5a9a.png)

I assume [these](https://nl.aliexpress.com/item/32805447244.html?gatewayAdapt=glo2nld&spm=a2g0o.detail.1000060.2.66c86b3cT3fMnU&gps-id=pcDetailBottomMoreThisSeller&scm=1007.13339.169870.0&scm_id=1007.13339.169870.0&scm-url=1007.13339.169870.0&pvid=c0c2f827-e31b-42b1-863f-2176d632c1cd&_t=gps-id:pcDetailBottomMoreThisSeller,scm-url:1007.13339.169870.0,pvid:c0c2f827-e31b-42b1-863f-2176d632c1cd,tpp_buckets:668%232846%238114%231999&pdp_ext_f=%257B%2522sku_id%2522%253A%252264304028955%2522%252C%2522sceneId%2522%253A%25223339%2522%257D&pdp_pi=-1%253B1.01%253B-1%253B-1%2540salePrice%253BUSD%253Brecommend-recommend) 5.5mm female DC jacks will fit to them, so I don't need to start cutting of my cables:

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/4/d/4d79a3c4b923b0913186160292aac9c6dcf1ed89.png)

That way the setup becomes very solid and simple:

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/0/9/09cd617e352b7e998864c34b0e104e5fd10fb2ba.jpeg)

Unless somebody sees something nasty that I have forgotten, I am going to put some stuff into my shopping basket 😉

BTW on the above link (about the splitters), I see also an example image of a Raspberry being powered via POE:

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/8/5/85099fdc91cbe733b54471e827c0c22fc1cc17de.jpeg)

I assume you will need a more expensive POE switch to be able to power a series of those devices. However just wanted to share it here, because it might trigger the creativity of some folks in this community...

[Next page](https://discourse.nodered.org/t/use-a-poe-switch-to-power-esp32-wired/58696.md?page=2)