Is there a way to support / donate to this project? / Core400s Guide addition

[kocy33]

Hello,

First I would like to say thank you for all the effort. Did you actually buy all these devices???
I haven't even converted my two 400s yet but i am going to convert them soon with an added C3.
Do you need additional photos?

Also do you have a kofi or paypal account?
I would really like to make a small donation for all the effort.

Edit 03.06.2026:
I have now successfully converted one of my levoit core 400s.
I managed to remove the top using 11 of "IFIXIT - Picks".
I had to twist the black part counterclockwise.
(See Photos)
That way i was able to unplug the cables and work comfortably.
Afterwards i was able to assemble everything again, without extensions on the cables.

I also identified the rx and tx pins on the mainboard Core400S_Ctrl_V1.2 it is TP33 and TP29.
(This was not directly mentioned in the guide)
To get the 5V for my ESP32-C3 I used the 5v Pin from J4.

Following here some Photos you are free to use for the Guide :)
If theres anything unclear feel free to ask.

Edit: To be clear i still had to remove the 6 screws in the Filter compartment. Otherwise the black top part would not detach.

[GRaNTMaTT]

@kocy33 I have been trying to get the top off my 400s with 11+ picks and I cannot for the life of me get it to release. You wouldn't happen to have a video of how you did it? My fingers are almost bleeding from trying :(

[kocy33]

I feel you.
When I tried it, I wasnt even sure if it works and it felt even more desperate. AND even worse > when I assembled everything again and put everything on again I managed to snap the ground wire and had to disassemble everything again...
I have to say the second time opeinig it is easier haha...

I actually still need to convert my second levoit 400s.
When I open that one I can try to make a video. :)

[GRaNTMaTT]

I am wondering if using a hair dryer to heat it all up might help. I am determined to get this done today ;)

[kocy33]

Good luck. The silver Ring and the case part interlock like on this picture. So you have to like move the Black part being locked up with the ring. Spreading the silver ring from the case without snapping anything.

[GRaNTMaTT]

So the picks need to be be between the silver and black? Or the silver and white? Your pic shows between the silver and white. Also, mine has 6 screws with washers on them inside the bottom barrel. I am not sure how @tuct got to the board coming from the bottom. The control ribbon cables are too short to get my hands in to disconnect from the board. I am going to hit with a hair dryer to see if I can get it to realease.

[kocy33]

You need to remove the screws in the filter departement and pull the Black Fan Box back.
Otherwise you can't twist the black grill.

You are right. You need to put the picks in between the case and ring. You need to release the ring from being locked in the groves of the case. Otherwise you can't twist it.

Tuct actually slit a knife in the handle hole and managed to pull back the taps that hold the board.
I found that incredible hard and thats why i tried it this way... he also had to extend the wires because mounting it like that is impossible.

Edit: at least that's what I think he did...

Edit2: these corners need to be free so you can twist it like all around... i recommend a flashlight.

[GRaNTMaTT]

I got it! I used the hair dryer and enlisted my wife to help hold the barrel. We both had rubberized gardening gloves on :) I was ready to give up and then jammed one more pick in and something popped. We gave it another heave ho and blammo!

[kocy33]

Congrats!
Haha my wife had to help me too... maybe that was missing in my description... 😄

If you need help in where to solder to just ask away. Otherwise good luck 👍

[GRaNTMaTT]

I have the esp32 module, but I am kind of thinking of just flashing the built in esp32 and not adding a second esp32 with a switch. I am working out how I want to go about this.

[kocy33]

I just disabled the inbuilt one with the bridge with j1 pin 3 to 6.

I flashed my esp32-c3 beforehand and was able to connect to it, before I was soldering it up. That way I could send updates to the code wirelessly, without having to have wire it up.
I don't intend to use stock firmware again but the esp32-c3 was incredibly cheap and small so I didn't have to bother with backing up and flashing the build in chip.

Just my reasoning.

[GRaNTMaTT]

I am ready to solder it up. Am I seeing it correctly that you used the ground on J3 combined with the white jumper from J6?

[kocy33]

J1 is all the pins down there on the last picture I posted on my original post. And I made a connection between gnd (pin3) and en (pin6). (That disables the on-board original esp)

I also used the gnd from pin 3 for the gnd of my esp32-c3 and the 5v i piggy backed from j4 . 5v.

[GRaNTMaTT]

Weird, I wired it up just like your pictures and I am getting no data on tx/rx.

[kocy33]

Rx from your esp32 needs to be wired up to tx of the board and tx to rx. You can also switch that in software

[GRaNTMaTT]

Looked identical to yours. This was way more work than I expected for today. I will open it back up tomorrow morning to see what's what. Thank for you help getting me this far!

[GRaNTMaTT]

Hey @kocy33 I am back! I pulled the boards, resoldered everything. I want to test it before I put it all back in the unit. Could I trouble you for a copy of your yaml file? I just used the one in the main instructions and I am not sure if I have the rx/tx wires connected to the esp32 correctly.

I have the yellow wire connected to tx-tp29 to D0 on the esp32 and the green wire connected to tr-tp33 to D10 on the esp32.

[GRaNTMaTT]

I was able to get it figured out and working. At least for a little bit. I can see the 400s in HA and can see stats, but now I cannot control the fan or turn the unit on and off. I was able to once ChatGPT helped me figure out the wiring. I could control fan speeds as well as turn it on and off. I unplugged/plugged the power on the 400s and it pops back on HA, shows online and I see sensor data, but cannot control the fan speed or turn it on or off. Any ideas?

[tuct]

Hi!
If you can read the sensor, but you can not control anything, it most likely means one of 2 things:
a) ESP32 -> MCU not connected correctly
b) Original ESP32 still active? Check if the device reports online in the original software

Also can you check 2 things:

• Version of the PCB Core400_Controll 1.2 says mine on the PCB
• Firmware version (needs device to be using original ESP32 and to be online to check, or from my FW in HA)

[kocy33]

Hey @kocy33 I am back! I pulled the boards, resoldered everything. I want to test it before I put it all back in the unit. Could I trouble you for a copy of your yaml file? I just used the one in the main instructions and I am not sure if I have the rx/tx wires connected to the esp32 correctly.

I have the yellow wire connected to tx-tp29 to D0 on the esp32 and the green wire connected to tr-tp33 to D10 on the esp32.

My guess is your tx wire got lose please check if its really soldered on!

Also your code has to represent the pins you were using on your esp32.
If it helps this is the code I am using for my ESP32-C3.
Please note you can't use it copy paste and you have to adjust board and your secrets of course.
(Also adjust the rx_pin and tx_pin in the section substitutions to represent your Pin D0 and D10. (GPIO00 and GPIO10))

Also yeah like tuct said please check if the bridge to disable the build in esp is correct.

substitutions:
  device_name: levoit-core400s-x1
  wifi_ap_ssid: "Levoit-Core400S-X1"
  rx_pin: GPIO04
  tx_pin: GPIO05

esphome:
  name: ${device_name}
  friendly_name: ${device_name}

esp32:
  board: esp32-c3-devkitm-1
  framework:
    type: esp-idf

# Enable Home Assistant API
api:
  encryption:
    key: "secret"

ota:
  - platform: esphome
    password: "secret"

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "${wifi_ap_ssid}"
    password: "secret"

captive_portal:

external_components:
  - source:
      type: git
      url: https://github.com/tuct/levoit
      ref: main
    components: [levoit]

logger:
  level: VERBOSE

uart:
  - id: uart_mcu2esp
    tx_pin:
      number: ${tx_pin}
      inverted: false
    rx_pin:
      number: ${rx_pin}
      inverted: false
    baud_rate: 115200

levoit:
  id: levoitcore400
  model: CORE400S

fan:
  - platform: levoit
    levoit: levoitcore400
    name: "Fan"
    id: levoit_fan1

switch:
  - platform: levoit
    levoit: levoitcore400
    name: "Display"
    type: display
  - platform: levoit
    levoit: levoitcore400
    name: "Child Lock"
    type: child_lock

number:
  - platform: levoit
    levoit: levoitcore400
    name: "Timer (min)"
    type: timer
  - platform: levoit
    levoit: levoitcore400
    name: "Auto Mode Room Size"
    type: efficiency_room_size
  - platform: levoit
    levoit: levoitcore400
    name: "Filter Months"
    type: filter_lifetime_months

sensor:
  - platform: levoit
    levoit: levoitcore400
    name: "AQ - PM 2.5"
    type: pm25
  - platform: levoit
    levoit: levoitcore400
    name: "AQI"
    type: aqi
  - platform: levoit
    levoit: levoitcore400
    name: "Current CADR"
    type: current_cadr
  - platform: levoit
    levoit: levoitcore400
    name: "Filter %"
    type: filter_life_left

select:
  - platform: levoit
    levoit: levoitcore400
    name: "Auto Mode"
    type: auto_mode

text_sensor:
  - platform: levoit
    levoit: levoitcore400
    name: "MCU Version"
    type: mcu_version
  - platform: levoit
    levoit: levoitcore400
    name: "ESP Version"
    type: esp_version
  - platform: levoit
    levoit: levoitcore400
    name: "Timer Duration"
    type: timer_duration_initial
  - platform: levoit
    levoit: levoitcore400
    name: "Timer Remaining"
    type: timer_duration_remaining
  - platform: levoit
    levoit: levoitcore400
    name: "Error"
    type: error_message

button:
  - platform: levoit
    levoit: levoitcore400
    name: "Filter Reset"
    type: reset_filter_stats

binary_sensor:
  - platform: levoit
    levoit: levoitcore400
    name: "Filter Low"
    type: filter_low    

[kocy33]

@GRaNTMaTT
If you'd like we could also chat on discord or matrix or something like that and we could troubleshoot more immediate if you'd like. :)

[tuct]

Hi @kocy33
If you have time and enhance the documentation and add photos (just create a PR), that would be awesome!

No donations needed! But help with the project would be great.

And, yes i own all the devices now, started with one LV-131 (not supported with this but i have a dedicated project) and added a Core 300s and a Core 400s.
All the others I acquired used to be able to reverse engineer and test them my self.

I could not get my 400s open like you guys did, failed to open the top, even designed a dedicated "tool" but still failed.
I managed to remove the logic board from the side and used way longer cables to reconnect!

Would be awesome if you could add your version to the readme for the core400s!

[kocy33]

Hi @tuct !
Thanks for the Sensor Update for the 400S. :)
Im gonna install that today and test it.

I will make a PR for the Core 400S to update the guide with solder points and method of disassembly!
I'll have to write a disclaimer that it is nerve wreckingly sweat inducing though!

Wow your Air has to be on a level of "cleanroom for silicon manufacturing" - given all these air-purifiers! haha 😆
Please think about getting a ko-fi account!
I bet there are some people that did the conversion and are happy with it and just want to show their appreciation. :)

edit:
I am really intrigued about how you did it as well.
If i were to try reversing what a mcu does in a device, would you advice getting a Saleae Logic?
Or whats a good Logic Analyzer to get into?

[tuct]

Hi @kocy33

I started trying to use the existing solutions that I found for the core300s but was quite unhappy cause they crashed for me quite often.

I got a Saleae Logic 8 now, quite pricy but very good! Before that i used the cheap ones for a few bugs and i have to say that they work very well to check uart/i2c stuff. I would not need my Salae for this! It has analog channels as well and in a bit more stable but not really needed.

TLDR: i used one like this so far: https://amzn.to/4v5tcrD
BTW: this is an affiliate link ;) - Ah and I added a Ko-Fi Button

I got my EverestAir 2 days ago and already have it up and running, took me about 2h to get it open and adopt the FW as it was super close to the Vital anyway, just more sensors and the ventilation angle added ;)

Check the main readme : I wrote a small analyzer for the Levoit protocols ;)