DS18b20 over OneWire bus Found no Devices

Levin243 · April 23, 2025, 2:01pm

Hello everyone!

This is my first post here, so if you have any suggestions or feedback, feel free to share!
Also, English is not my first language, so please excuse any mistakes.

The issue:
My setup was working fine—until it suddenly wasn’t. After spending quite some time researching across different forums, I ended up more confused than before.

I hope someone of you can help me with that and Thanks in advance!

What’s happening:

I can upload the code to the ESP32 without any errors.
I have several DS18B20 temperature sensors connected via a OneWire bus. The ESP32 is running ESPHome.
I first noticed the issue when all 5 sensors started showing either 0.0 or nan in my Home Assistant dashboard.
The logs indicate that no devices are found on the OneWire bus.
Interestingly, everything else works fine: I can control the relays, and the binary sensor is also functioning as expected.

What I’ve tested so far:

I double-checked the physical connections, especially between the sensors and the PCB.
I also flashed the YAML configuration to another ESP32 of the same type—same result.

My research:

In several threads, I found mentions of recent changes in how the OneWire bus and Dallas temperature sensors are configured in ESPHome.
Unfortunately, I came across a lot of different approaches, many of which led to errors during compilation or just didn’t work at all.

My setup:

Home Assistant Core Version: 2025.4.3
Home Assistant OS Version: 15.2
ESPHome Version: 2025.04.0
Board: ESP32-S3-DevKitC-1
Sensors: DS18B20
Connection type: OneWire Bus

The Log Output:

INFO ESPHome 2025.4.0
INFO Reading configuration /config/esphome/esp32-poolsteuerung.yaml...
INFO Starting log output from ------------------ using esphome API
INFO Successfully connected to esp32-poolsteuerung @ --------------------in 0.082s
INFO Successful handshake with esp32-poolsteuerung @ ------------------- in 0.075s
[15:20:09][I][app:100]: ESPHome version 2025.4.0 compiled on Apr 23 2025, 14:56:22
[15:20:09][C][wifi:600]: WiFi:
[15:20:09][C][wifi:428]:   Local MAC: ---------------------
[15:20:09][C][wifi:433]:   SSID: [redacted]
[15:20:09][C][wifi:436]:   IP Address: --------------------
[15:20:09][C][wifi:440]:   BSSID: [redacted]
[15:20:09][C][wifi:441]:   Hostname: 'esp32-poolsteuerung'
[15:20:09][C][wifi:443]:   Signal strength: -75 dB ▂▄▆█
[15:20:09][V][wifi:445]:   Priority: -2.0
[15:20:09][C][wifi:447]:   Channel: 11
[15:20:09][C][wifi:448]:   Subnet: ------------------
[15:20:09][C][wifi:449]:   Gateway: -------------------
[15:20:09][C][wifi:450]:   DNS1: --------------------
[15:20:09][C][wifi:451]:   DNS2: 0.0.0.0
[15:20:09][C][logger:177]: Logger:
[15:20:09][C][logger:178]:   Max Level: VERBOSE
[15:20:09][C][logger:179]:   Initial Level: VERBOSE
[15:20:09][C][logger:181]:   Log Baud Rate: 115200
[15:20:09][C][logger:182]:   Hardware UART: USB_CDC
[15:20:09][C][gpio.one_wire:020]: GPIO 1-wire bus:
[15:20:09][C][gpio.one_wire:021]:   Pin: GPIO14
[15:20:09][W][gpio.one_wire:078]:   Found no devices!                   <------------- Here
[15:20:09][C][switch.gpio:068]: GPIO Switch 'PS_Relais_1'
[15:20:09][C][switch.gpio:076]:   Inverted: YES
[15:20:09][C][switch.gpio:091]:   Restore Mode: always OFF
[15:20:09][C][switch.gpio:031]:   Pin: GPIO18
[15:20:09][C][switch.gpio:068]: GPIO Switch 'PS_Relais_2'
[15:20:09][C][switch.gpio:076]:   Inverted: YES
[15:20:09][C][switch.gpio:091]:   Restore Mode: always OFF
[15:20:09][C][switch.gpio:031]:   Pin: GPIO17
[15:20:09][C][switch.gpio:068]: GPIO Switch 'PS_Relais_3'
[15:20:09][C][switch.gpio:076]:   Inverted: YES
[15:20:09][C][switch.gpio:091]:   Restore Mode: always OFF
[15:20:09][C][switch.gpio:031]:   Pin: GPIO16
[15:20:09][C][switch.gpio:068]: GPIO Switch 'PS_Relais_4'
[15:20:09][C][switch.gpio:076]:   Inverted: YES
[15:20:09][C][switch.gpio:091]:   Restore Mode: always OFF
[15:20:09][C][switch.gpio:031]:   Pin: GPIO15
[15:20:09][C][switch.gpio:068]: GPIO Switch 'PS_Relais_5'
[15:20:09][C][switch.gpio:076]:   Inverted: YES
[15:20:09][C][switch.gpio:091]:   Restore Mode: always OFF
[15:20:09][C][switch.gpio:031]:   Pin: GPIO7
[15:20:09][C][switch.gpio:068]: GPIO Switch 'PS_Relais_8_WP'
[15:20:09][C][switch.gpio:076]:   Inverted: YES
[15:20:09][C][switch.gpio:091]:   Restore Mode: always OFF
[15:20:09][C][switch.gpio:031]:   Pin: GPIO4
[15:20:09][C][gpio.binary_sensor:015]: GPIO Binary Sensor 'Durchfluss'
[15:20:09][C][gpio.binary_sensor:016]:   Pin: GPIO47
[15:20:09][C][dallas.temp.sensor:029]: Dallas Temperature Sensor:
[15:20:09][C][dallas.temp.sensor:034]:   Address: 0x8ae7c6570a646128 (DS18B20)
[15:20:09][C][dallas.temp.sensor:035]:   Resolution: 12 bits
[15:20:09][C][dallas.temp.sensor:036]:   Update Interval: 5.0s
[15:20:09][C][dallas.temp.sensor:029]: Dallas Temperature Sensor:
[15:20:09][C][dallas.temp.sensor:034]:   Address: 0x9e5e63560a646128 (DS18B20)
[15:20:09][C][dallas.temp.sensor:035]:   Resolution: 12 bits
[15:20:09][C][dallas.temp.sensor:036]:   Update Interval: 5.0s
[15:20:09][C][dallas.temp.sensor:029]: Dallas Temperature Sensor:
[15:20:09][C][dallas.temp.sensor:034]:   Address: 0x0f47cb211864ff28 (DS18B20)
[15:20:09][C][dallas.temp.sensor:035]:   Resolution: 12 bits
[15:20:09][C][dallas.temp.sensor:036]:   Update Interval: 5.0s
[15:20:09][C][dallas.temp.sensor:029]: Dallas Temperature Sensor:
[15:20:09][C][dallas.temp.sensor:034]:   Address: 0x2a3c01d6077d3a28 (DS18B20)
[15:20:09][C][dallas.temp.sensor:035]:   Resolution: 12 bits
[15:20:09][C][dallas.temp.sensor:036]:   Update Interval: 5.0s
[15:20:09][C][dallas.temp.sensor:029]: Dallas Temperature Sensor:
[15:20:09][C][dallas.temp.sensor:034]:   Address: 0x99baf9570a646128 (DS18B20)
[15:20:09][C][dallas.temp.sensor:035]:   Resolution: 12 bits
[15:20:09][C][dallas.temp.sensor:036]:   Update Interval: 5.0s
[15:20:09][C][captive_portal:089]: Captive Portal:
[15:20:09][C][mdns:116]: mDNS:
[15:20:09][C][mdns:117]:   Hostname: esp32-poolsteuerung
[15:20:09][V][mdns:118]:   Services:
[15:20:09][V][mdns:120]:   - _esphomelib, _tcp, 6053
[15:20:09][V][mdns:122]:     TXT: version = 2025.4.0
[15:20:09][V][mdns:122]:     TXT: mac = c04e3037d804
[15:20:09][V][mdns:122]:     TXT: platform = ESP32
[15:20:09][V][mdns:122]:     TXT: board = esp32-s3-devkitc-1
[15:20:09][V][mdns:122]:     TXT: network = wifi
[15:20:09][V][mdns:122]:     TXT: api_encryption = Noise_NNpsk0_25519_ChaChaPoly_SHA256
[15:20:09][C][esphome.ota:073]: Over-The-Air updates:
[15:20:09][C][esphome.ota:074]:   Address: esp32-poolsteuerung.local:3232
[15:20:09][C][esphome.ota:075]:   Version: 2
[15:20:09][C][esphome.ota:078]:   Password configured
[15:20:09][C][safe_mode:018]: Safe Mode:
[15:20:09][C][safe_mode:020]:   Boot considered successful after 60 seconds
[15:20:09][C][safe_mode:021]:   Invoke after 10 boot attempts
[15:20:09][C][safe_mode:023]:   Remain in safe mode for 300 seconds
[15:20:09][C][api:140]: API Server:
[15:20:09][C][api:141]:   Address: esp32-poolsteuerung.local:6053
[15:20:09][C][api:143]:   Using noise encryption: YES
[15:20:09][W][component:172]: Component dallas_temp.sensor cleared Warning flag
[15:20:09][W][component:172]: Component dallas_temp.sensor cleared Warning flag
[15:20:09][W][component:172]: Component dallas_temp.sensor cleared Warning flag
[15:20:10][W][dallas.temp.sensor:139]: 'Temp RL WP/VL Dach' - Scratch pad checksum invalid!
[15:20:10][W][component:157]: Component dallas_temp.sensor set Warning flag: scratch pad checksum invalid
[15:20:10][V][sensor:043]: 'Temp RL WP/VL Dach': Received new state nan
[15:20:10][D][sensor:094]: 'Temp RL WP/VL Dach': Sending state nan °C with 1 decimals of accuracy
[15:20:10][W][component:172]: Component dallas_temp.sensor cleared Warning flag
[15:20:10][W][dallas.temp.sensor:139]: 'Temp VL WP' - Scratch pad checksum invalid!
[15:20:10][W][component:157]: Component dallas_temp.sensor set Warning flag: scratch pad checksum invalid
[15:20:10][V][sensor:043]: 'Temp VL WP': Received new state nan
[15:20:10][D][sensor:094]: 'Temp VL WP': Sending state nan °C with 1 decimals of accuracy
[15:20:10][W][dallas.temp.sensor:139]: 'Temp Außen' - Scratch pad checksum invalid!
[15:20:10][W][component:157]: Component dallas_temp.sensor set Warning flag: scratch pad checksum invalid
[15:20:10][V][sensor:043]: 'Temp Außen': Received new state nan
[15:20:10][D][sensor:094]: 'Temp Außen': Sending state nan °C with 1 decimals of accuracy
[15:20:10][D][dallas.temp.sensor:054]: 'Temp Ansaugung Pool': Got Temperature=0.0°C
[15:20:10][V][sensor:043]: 'Temp Ansaugung Pool': Received new state 0.000000
[15:20:10][D][sensor:094]: 'Temp Ansaugung Pool': Sending state 0.00000 °C with 1 decimals of accuracy
[15:20:10][W][dallas.temp.sensor:139]: 'Temp Ausgang Pool' - Scratch pad checksum invalid!
[15:20:10][W][component:157]: Component dallas_temp.sensor set Warning flag: scratch pad checksum invalid
[15:20:10][V][sensor:043]: 'Temp Ausgang Pool': Received new state nan
[15:20:10][D][sensor:094]: 'Temp Ausgang Pool': Sending state nan °C with 1 decimals of accuracy
[15:20:14][W][component:172]: Component dallas_temp.sensor cleared Warning flag

The Yaml on the ESP:

esphome:
  name: esp32-poolsteuerung

esp32:
  board: esp32-s3-devkitc-1
  framework:
    type: arduino

logger:
  level: VERBOSE

api:
  encryption:
    key: ""

ota:
  platform: esphome
  password: ""

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

  ap:
    ssid: "Esp32-Poolsteuerung"
    password: ""

captive_portal:

# ------------------------------
switch:
  - platform: gpio
    name: "PS_Relais_1"
    pin: 18
    inverted: true

  - platform: gpio
    name: "PS_Relais_2"
    pin: 17
    inverted: true

  - platform: gpio
    name: "PS_Relais_3"
    pin: 16
    inverted: true

  - platform: gpio
    name: "PS_Relais_4"
    pin: 15
    inverted: true

  - platform: gpio
    name: "PS_Relais_5"
    pin: 7
    inverted: true

  - platform: gpio
    name: "PS_Relais_8_WP"
    pin: 4
    inverted: true

# ------------------------------
one_wire:
  - platform: gpio
    pin: 
      number: 14

# ------------------------------
sensor:
  - platform: dallas_temp
    address: 0x8ae7c6570a646128
    name: "Temp Ansaugung Pool"
    accuracy_decimals: 1
    unit_of_measurement: "°C"
    device_class: temperature
    update_interval: 5s

  - platform: dallas_temp
    address: 0x9e5e63560a646128
    name: "Temp VL WP"
    accuracy_decimals: 1
    unit_of_measurement: "°C"
    device_class: temperature
    update_interval: 5s

  - platform: dallas_temp
    address: 0x0f47cb211864ff28
    name: "Temp RL WP/VL Dach"
    accuracy_decimals: 1
    unit_of_measurement: "°C"
    device_class: temperature
    update_interval: 5s

  - platform: dallas_temp
    address: 0x2a3c01d6077d3a28
    name: "Temp Ausgang Pool"
    accuracy_decimals: 1
    unit_of_measurement: "°C"
    device_class: temperature
    update_interval: 5s

  - platform: dallas_temp
    address: 0x99baf9570a646128
    name: "Temp Außen"
    accuracy_decimals: 1
    unit_of_measurement: "°C"
    device_class: temperature
    update_interval: 5s

# ------------------------------
binary_sensor:
  - platform: gpio
    name: "Durchfluss"
    pin:
      number: 47

Karosm · April 23, 2025, 2:20pm

That’s how it goes…
How is your pull-up?
Problem with these is that if one sensor fails, it can take the whole bus down.

Levin243 · April 23, 2025, 2:54pm

Hi, thanks for the fast reply.

How is your pull-up?

I tested it with a Mulimeter and it is measuing the right 4.7kΩ.

This is my PCB. The GND is on the back.

Karosm · April 23, 2025, 3:11pm

Pull-up should be to 3.3v

Levin243 · April 23, 2025, 3:17pm

Pull-up should be to 3.3v

Okay, I followed the instruction below. But why did it work before if that is an issue?

Karosm · April 23, 2025, 3:21pm

That is valid for 5v arduino, not for 3.3v esp.
Maybe your gpio pin gave up after long abuse.
Or it’s still alive and simply one sensor got faulty.
Test with some other pin.

Levin243 · April 23, 2025, 3:55pm

I rerouted a new resistor and the bus pin and tested pin 13 and 10, both with the same result.

So next I should disconnect the temp sensors and reconnect them one by one right?

INFO ESPHome 2025.4.0
INFO Reading configuration /config/esphome/esp32-poolsteuerung.yaml...
INFO Starting log output from 192.168.188.69 using esphome API
INFO Successfully connected to esp32-poolsteuerung @ -------------------in 0.043s
INFO Successful handshake with esp32-poolsteuerung @ -------------------in 0.065s
[17:52:26][I][app:100]: ESPHome version 2025.4.0 compiled on Apr 23 2025, 17:45:01
[17:52:26][C][wifi:600]: WiFi:
[17:52:26][C][wifi:428]:   Local MAC: -------------------
[17:52:26][C][wifi:433]:   SSID: [redacted]
[17:52:26][C][wifi:436]:   IP Address: -------------------
[17:52:26][C][wifi:440]:   BSSID: [redacted]
[17:52:26][C][wifi:441]:   Hostname: 'esp32-poolsteuerung'
[17:52:26][C][wifi:443]:   Signal strength: -73 dB ▂▄▆█
[17:52:26][V][wifi:445]:   Priority: 0.0
[17:52:26][C][wifi:447]:   Channel: 11
[17:52:26][C][wifi:448]:   Subnet: -------------------
[17:52:26][C][wifi:449]:   Gateway: -------------------
[17:52:26][C][wifi:450]:   DNS1: -------------------
[17:52:26][C][wifi:451]:   DNS2: 0.0.0.0
[17:52:26][C][logger:177]: Logger:
[17:52:26][C][logger:178]:   Max Level: VERBOSE
[17:52:26][C][logger:179]:   Initial Level: VERBOSE
[17:52:26][C][logger:181]:   Log Baud Rate: 115200
[17:52:26][C][logger:182]:   Hardware UART: USB_CDC
[17:52:26][C][gpio.one_wire:020]: GPIO 1-wire bus:
[17:52:26][C][gpio.one_wire:021]:   Pin: GPIO10
[17:52:26][W][gpio.one_wire:078]:   Found no devices!
[17:52:26][C][switch.gpio:068]: GPIO Switch 'PS_Relais_1'
[17:52:26][C][switch.gpio:076]:   Inverted: YES
[17:52:26][C][switch.gpio:091]:   Restore Mode: always OFF
[17:52:26][C][switch.gpio:031]:   Pin: GPIO18
[17:52:26][C][switch.gpio:068]: GPIO Switch 'PS_Relais_2'
[17:52:26][C][switch.gpio:076]:   Inverted: YES
[17:52:26][C][switch.gpio:091]:   Restore Mode: always OFF
[17:52:26][C][switch.gpio:031]:   Pin: GPIO17
[17:52:26][C][switch.gpio:068]: GPIO Switch 'PS_Relais_3'
[17:52:26][C][switch.gpio:076]:   Inverted: YES
[17:52:26][C][switch.gpio:091]:   Restore Mode: always OFF
[17:52:26][C][switch.gpio:031]:   Pin: GPIO16
[17:52:26][C][switch.gpio:068]: GPIO Switch 'PS_Relais_4'
[17:52:26][C][switch.gpio:076]:   Inverted: YES
[17:52:26][C][switch.gpio:091]:   Restore Mode: always OFF
[17:52:26][C][switch.gpio:031]:   Pin: GPIO15
[17:52:26][C][switch.gpio:068]: GPIO Switch 'PS_Relais_5'
[17:52:26][C][switch.gpio:076]:   Inverted: YES
[17:52:26][C][switch.gpio:091]:   Restore Mode: always OFF
[17:52:26][C][switch.gpio:031]:   Pin: GPIO7
[17:52:26][C][switch.gpio:068]: GPIO Switch 'PS_Relais_8_WP'
[17:52:26][C][switch.gpio:076]:   Inverted: YES
[17:52:26][C][switch.gpio:091]:   Restore Mode: always OFF
[17:52:26][C][switch.gpio:031]:   Pin: GPIO4
[17:52:26][C][gpio.binary_sensor:015]: GPIO Binary Sensor 'Durchfluss'
[17:52:26][C][gpio.binary_sensor:016]:   Pin: GPIO47
[17:52:26][C][dallas.temp.sensor:029]: Dallas Temperature Sensor:
[17:52:26][C][dallas.temp.sensor:034]:   Address: 0x8ae7c6570a646128 (DS18B20)
[17:52:26][C][dallas.temp.sensor:035]:   Resolution: 12 bits
[17:52:26][C][dallas.temp.sensor:036]:   Update Interval: 5.0s
[17:52:26][C][dallas.temp.sensor:029]: Dallas Temperature Sensor:
[17:52:26][C][dallas.temp.sensor:034]:   Address: 0x9e5e63560a646128 (DS18B20)
[17:52:26][C][dallas.temp.sensor:035]:   Resolution: 12 bits
[17:52:26][C][dallas.temp.sensor:036]:   Update Interval: 5.0s
[17:52:27][C][dallas.temp.sensor:029]: Dallas Temperature Sensor:
[17:52:27][C][dallas.temp.sensor:034]:   Address: 0x0f47cb211864ff28 (DS18B20)
[17:52:27][C][dallas.temp.sensor:035]:   Resolution: 12 bits
[17:52:27][C][dallas.temp.sensor:036]:   Update Interval: 5.0s
[17:52:27][C][dallas.temp.sensor:029]: Dallas Temperature Sensor:
[17:52:27][C][dallas.temp.sensor:034]:   Address: 0x2a3c01d6077d3a28 (DS18B20)
[17:52:27][C][dallas.temp.sensor:035]:   Resolution: 12 bits
[17:52:27][C][dallas.temp.sensor:036]:   Update Interval: 5.0s
[17:52:27][C][dallas.temp.sensor:029]: Dallas Temperature Sensor:
[17:52:27][C][dallas.temp.sensor:034]:   Address: 0x99baf9570a646128 (DS18B20)
[17:52:27][C][dallas.temp.sensor:035]:   Resolution: 12 bits
[17:52:27][C][dallas.temp.sensor:036]:   Update Interval: 5.0s
[17:52:27][C][captive_portal:089]: Captive Portal:
[17:52:27][C][mdns:116]: mDNS:
[17:52:27][C][mdns:117]:   Hostname: esp32-poolsteuerung
[17:52:27][V][mdns:118]:   Services:
[17:52:27][V][mdns:120]:   - _esphomelib, _tcp, 6053
[17:52:27][V][mdns:122]:     TXT: version = 2025.4.0
[17:52:27][V][mdns:122]:     TXT: mac = c04e3037d804
[17:52:27][V][mdns:122]:     TXT: platform = ESP32
[17:52:27][V][mdns:122]:     TXT: board = esp32-s3-devkitc-1
[17:52:27][V][mdns:122]:     TXT: network = wifi
[17:52:27][V][mdns:122]:     TXT: api_encryption = Noise_NNpsk0_25519_ChaChaPoly_SHA256
[17:52:27][C][esphome.ota:073]: Over-The-Air updates:
[17:52:27][C][esphome.ota:074]:   Address: esp32-poolsteuerung.local:3232
[17:52:27][C][esphome.ota:075]:   Version: 2
[17:52:27][C][esphome.ota:078]:   Password configured
[17:52:27][C][safe_mode:018]: Safe Mode:
[17:52:27][C][safe_mode:020]:   Boot considered successful after 60 seconds
[17:52:27][C][safe_mode:021]:   Invoke after 10 boot attempts
[17:52:27][C][safe_mode:023]:   Remain in safe mode for 300 seconds
[17:52:27][C][api:140]: API Server:
[17:52:27][C][api:141]:   Address: esp32-poolsteuerung.local:6053
[17:52:27][C][api:143]:   Using noise encryption: YES
[17:52:29][D][dallas.temp.sensor:054]: 'Temp Ansaugung Pool': Got Temperature=0.0°C
[17:52:29][V][sensor:043]: 'Temp Ansaugung Pool': Received new state 0.000000
[17:52:29][D][sensor:094]: 'Temp Ansaugung Pool': Sending state 0.00000 °C with 1 decimals of accuracy
[17:52:29][D][dallas.temp.sensor:054]: 'Temp Außen': Got Temperature=0.0°C
[17:52:29][V][sensor:043]: 'Temp Außen': Received new state 0.000000
[17:52:29][D][sensor:094]: 'Temp Außen': Sending state 0.00000 °C with 1 decimals of accuracy
[17:52:29][D][dallas.temp.sensor:054]: 'Temp VL WP': Got Temperature=0.0°C
[17:52:29][V][sensor:043]: 'Temp VL WP': Received new state 0.000000
[17:52:29][D][sensor:094]: 'Temp VL WP': Sending state 0.00000 °C with 1 decimals of accuracy
[17:52:30][D][dallas.temp.sensor:054]: 'Temp Ausgang Pool': Got Temperature=0.0°C
[17:52:30][V][sensor:043]: 'Temp Ausgang Pool': Received new state 0.000000
[17:52:30][D][sensor:094]: 'Temp Ausgang Pool': Sending state 0.00000 °C with 1 decimals of accuracy
[17:52:30][D][dallas.temp.sensor:054]: 'Temp RL WP/VL Dach': Got Temperature=0.0°C
[17:52:30][V][sensor:043]: 'Temp RL WP/VL Dach': Received new state 0.000000
[17:52:30][D][sensor:094]: 'Temp RL WP/VL Dach': Sending state 0.00000 °C with 1 decimals of accuracy

Karosm · April 23, 2025, 4:06pm

I don’t have anything better to suggest.

Levin243 · April 23, 2025, 5:27pm

That took some time, but it worked!

Thank you very much Karosm!

You were right with both.

Maybe your gpio pin gave up after long abuse.

Or it’s still alive and simply one sensor got faulty.

I connected a known good sensor to the old esp and it didn’t work.
Next i connected it to the new esp and it worked. (as expected)
Then I connected the new esp to the old Sensors and it didn’t work again.

In conclusion RIP to one ESP32 and 3x DS18B20.

And thanks again!

Karosm · April 23, 2025, 5:52pm

Nice!
We have a school example of Esp gpio abuse, very famous argument on this forum people “confirming” esp as tolerant to 5V because the magic smoke doesn’t puff at the moment of connecting wire.
Would you mind to measure pin voltage high/low of the damaged board?

Levin243 · April 25, 2025, 3:32pm

Hello,

I don’t mind testing the ESP at all — I’ll give it a try over the weekend.

But I dug a bit deeper, and I think I might’ve found the actual problem. Not sure if testing the ESP will really say much about how tolerant it is anymore, but we’ll see.

So, two of the sensor cables run through an “empty” pipe underground… turns out, that pipe was full of water.

To check if that was causing the issue, I unplugged the sensors and reconnected the cables to my working ESP and the running bus. Vcc and GND were fine — but as soon as I connected one of the data lines, the whole bus went down.

So right now, my best guess is that at least two of the cables have damaged insulation and water got in.

I’ll swap out the cables and test the sensors again.

Will report back once that’s done.