M5 Atom Lite and ENV IV sensor

ESPHome
1

Trying to connect M5 Atom Lite and ENV-IV sensor, which has BMP280 and SHT40 on the I2C. Both sensors are visible when I run a basic I2C detection script (at 0x76 and 0x44) on the Atom.

this is my ESPHome YAML:

esphome:
  name: esphome-web-fd8e04
  friendly_name: Lounge-Atom
  min_version: 2024.11.0
  name_add_mac_suffix: false

esp32:
  board: esp32dev
  framework:
    type: esp-idf

# Enable logging
logger:

# Enable Home Assistant API
api:

# Allow Over-The-Air updates
ota:
- platform: esphome

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

i2c:
  scl: 21
  sda: 25
  scan: true

sensor:
  - platform: sht4x
    temperature:
      name: "SHT40 Temperature"
    humidity:
      name: "SHT40 Relative Humidity"
  - platform: bmp280_i2c
    address: 0x76
    temperature:
      name: "BMP280 Temperature"
      oversampling: 16x
    pressure:
      name: "BMP280 Pressure"

bluetooth_proxy:

During compiling/install I get:

src/esphome/components/sht4x/sht4x.cpp: In member function 'virtual void esphome::sht4x::SHT4XComponent::setup()':
src/esphome/components/sht4x/sht4x.cpp:22:63: warning: arithmetic between enumeration type 'esphome::sht4x::SHT4XHEATERTIME' and floating-point type 'float' is deprecated [-Wdeprecated-enum-float-conversion]
   22 |     uint32_t heater_interval = (uint32_t) (this->heater_time_ / this->duty_cycle_);

I then get this error after upload

[E][bmp280.sensor:135]: Communication with BMP280 failed!

and finally this when it’s running

[D][sht4x:080]: Sensor read failed

Can anyone suggest where I’m going wrong with this?

2

You need to specify the sht4x address (0x44).
The BMP address could be 0x77, depending whether you wired SDO the GND or VCC. It cannot be left floating.

3

If you don’t have options on your yaml for heater time, the warnings look like a bug.
You might want to set board: m5stack-atom
May I suggest you to try one sensor at the time, it’s making it much easier.

4

SOLVED - The SDA and SCL on the grove connector are 26 and 32; 25 and 21 are the external pins on the Atom.