DS18B20 working on esp32cam but not on esp32WROOM

Hey there,

Had a DS18B20 working for months on ESP32WROOM. Did many test / changes last week but finally choose to put back the DS18B20 back on my ESP32WROOM.

As I said, it was working fine for months. I put back the exactly same DS18B20 on the exactly same ESP32WROOM on the same GPIO27, but the logs tells me “Found no sensors!” when in DEBUG mode.

What I tried :

  • Changing resistor (4.7, 2.2, many others) => Not working on esp32WROOM, working on an ESP32CAM
  • Without resistor => Not working on esp32WROOM, working on an ESP32CAM
  • Another DS18B20 => Not working on esp32WROOM, both working on an ESP32CAM
  • Connecting a physical switch (like this one) and trigger it => Working on esp32WROOM and ESP32CAM
  • Many different USB charger and USB cables
  • Other GPIOs of course

My yaml :

esphome:
  name: "esptemp"

esp32:
  board: esp32dev
  framework:
    type: arduino

logger:
  level: DEBUG

api:
  encryption:
    key: "something"

ota:
  password: "something"

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

  ap:
    ssid: "Esptemp Fallback Hotspot"
    password: "something"

captive_portal:

dallas:
  - pin: GPIO27 # Tried GPIO27 too

sensor: # Tried with and without this part, caught the address on my old yaml when it was working, don't know if the address can change or if it always the same ?
  - platform: dallas
    address: 0x6eefa85b1f64ff28
    name: "Temp"

Strange isn’t it ? :sweat_smile: It looks like the DS18B20 sensor ONLY isn’t working anymore on ESP32WROOM.

I made the latest firmware update (ESPHOME 2023.10.6), could it be related ?

Thanks for your help :slight_smile:

Hey again,

Just tried with another esp32WROOM this morning, same problem. Could it be a firmware issue ?

Ty !

Did you figure this out? I think I have a similar issue. I checked the values from my two DS18B20 sensors today, and one is 25.0 degrees, the other 85 degrees. I have not checked them for months, so I do not know when the issue started.

EDIT: Just going to say here that my issue appears to have been something hardware related with the ESP32. I swapped in a new esp32, everything else the same, added it to HA, and it is good. Before this, I removed the old esp32 from HA, and re-added it using ESPHome, and then put in the sensors in the yaml, but no help there,

For last year using following external component for DS18B20 (with external pullup).
It working on various ESP8266 and ESP32, incl. WROOM-32 boards.

external_components:
  - source: github://nrandell/dallasng