SI7021 Sonoff sensor wired to esp32

ESPHome
1

Hey All,

First attempt at using esp32 home. I’ve purchased these boards; Amazon.co.uk. (i think i have the board type correct)

flashed them and now up and going over OTA, i’m trying to wire up the Si7021 sensor. It has three wires, white, red and black. I have the White connected to 02, red to 3v3 and black to GND. flashed it with the below config;

esphome:
  name: kitchen
  platform: ESP32
  board: esp32doit-devkit-v1
#  board: nodemcu-32s

wifi:
  ssid: "Home"
  password: "<removed>"

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Kitchen Fallback Hotspot"
    password: "X3e69v28lq2z"

captive_portal:

# Enable logging
logger:

# Enable Home Assistant API
api:

ota:

sensor:
  - platform: dht
    pin: 2
    temperature:
      name: "Living Room Temperature"
    humidity:
      name: "Living Room Humidity"
    update_interval: 60s

and is complaining about this;

[21:45:57][W][dht:154]: Waiting for DHT communication to clear failed!
[21:45:57][W][dht:060]: Invalid readings! Please check your wiring (pull-up resistor, pin number) and consider manually specifying the DHT model using the model option.
[21:45:57][D][sensor:092]: ‘Living Room Temperature’: Sending state nan °C with 1 decimals of accuracy
[21:45:57][D][sensor:092]: ‘Living Room Humidity’: Sending state nan % with 0 decimals of accuracy

anyone have any thoughts?

2

Maybe try the htu21d platform.

That info comes from a note about the SI7021 sensor on this page.

Hope its of help.

3

Thanks, will try this configuration.

I have confired i2c, i’m not to sure which pins to connect the wires to now: i have the three from my sensor, 3v3, GND and Data.

Which one does the data connect to as i2c has two , 21 and 22?

4

This page should help.

And the data and clock pins should be marked on the SI7021, or it’s data sheet.

However this tells me its not a SI7021.

5

Thanks, this is what I purchased

SONOFF Si7021 Sensor Temperature and Humidity Sensor for SONOFF TH10 and SONOFF TH16 Smart WiFi Switch,(–40℃~85°C, 0~100% RH) High Accuracy Monitor Temperature Humidity Sensor https://www.amazon.co.uk/dp/B075LN2SQ2/ref=cm_sw_r_cp_api_i_AiaeFbVA0B893

6

It’s not i2c. I have a couple I use with a Sonoff S22 and works great. Perhaps check the Tasmota Template to see how it should be connected and configured.

7

That look to have 4 ring connector on the plug in the Amazon photo. :thinking:

edit: this might help as it has relevant info.

8 
sensor:
  - platform: dht
    pin: 2
    temperature:
      name: "Living Room Temperature"
    humidity:
      name: "Living Room Humidity"
    update_interval: 60s

You need to specify the model:

model ( Optional , int): Manually specify the DHT model, can be one of AUTO_DETECT , DHT11 , DHT22 , AM2302 , RHT03 , SI7021 and helps with some connection issues. Defaults to AUTO_DETECT . Auto detection doesn’t work for the SI7021 chip.

9

Support has been dropped after recent ESPhome update. Go back to tasmota as the sensor is a rigged 2 wire protocol, not i2c

10

Hello! I would like to raise this issue again. Since I am now faced with a support problem (the result is the same as in the original post) but with Sonoff THR316 (ESP32) and as I understand, nothing has changed yet, there is still no support?