I2C Multiplexer TCA9548A problem with ESPHome 2025.6.0

ESPHome
1

I am trying to use a TCA9549A multiplexer to interface 3 HX711 and 5 BME688 to a Adafruit itsyBitsy ESP32 wFL.

I get the following error on compile…

INFO ESPHome 2025.6.0-dev
INFO Reading configuration /config/esphome/wifihivescale.yaml…
ERROR Error while reading config: Invalid YAML syntax:

mapping values are not allowed here
in “/config/esphome/wifihivescale.yaml”, line 64, column 11
line 64 reads: i2c_id: multiplex0channel0

if I comment out the hx711 section: then I get:
[id] is an invalid option for [sensor.bme68x_bsec2]. Please check indentation.
id: bme688_hive33

[i2c_id] is an invalid option for [sensor.bme68x_bsec2]. Please check the indentation.
i2c_id: multiplex0channel1

Are the hx711 and the bme688 not supported by the TCA9548A multiplexer?

Here’s my .yaml:

 esphome:
  name: wifihivescale
  friendly_name: WifiHiveScale

esp32:
  board: esp32dev
  framework:
    type: arduino

# Enable logging
logger:

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

ota:
  - platform: esphome
    password: "xxxx"

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

i2c:
  id: i2c0
  sda: 15
  scl: 27
  scan: true


tca9548a:
  - address: 0x70
    id: multiplex0
    i2c_id: i2c0
    channels:
      - bus_id: multiplex0channel0
        channel: 0
      - bus_id: multiplex0channel1
        channel: 1
      - bus_id: multiplex0channel2
        channel: 2
      - bus_id: multiplex0channel3
        channel: 3
      - bus_id: multiplex0channel4
        channel: 4
      - bus_id: multiplex0channel5
        channel: 5
      - bus_id: multiplex0channel6
        channel: 6
      - bus_id: multiplex0channel7
        channel: 7
  
bme68x_bsec2_i2c:
  model: bme688
  sample_rate: ULP
  state_save_interval: 6h
    

# Individual I2C Devices
sensor:
- platform: hx711
    i2c_id: multiplex0channel0
    name: "WifiHiveScale 33"
    accuracy_decimals: 1
    update_interval: 60s
    filters:
      - calibrate_linear:
        - 120.0 -> 0
        - 810.0 -> 1
    unit_of_measurement: lb


- platform: bme68x_bsec2
    id: "bme688_hive33"
    i2c_id: multiplex0channel1
    #bme688_bsec_id: bme688_bsec
    
    temperature:
      name: "Hive 33 Temp"
      id: hive33_temperature
      sample_rate: ULP
      filters:
        - median

    humidity:
      name: "Hive 33 Humidity"
      id: hive33_humidity
      sample_rate: ULP
      filters:
        - median

    pressure:
      name: "Hive 33 Pressure"
      id: hive33_pressure
      icon: "mdi:gauge"
      sample_rate: ULP
      filters:
        - median

    gas_resistance: # in ohms
      name: "Hive 33 Gas Resistance"
      id: hive33_gas_resistance
      icon: "mdi:omega"
      filters:
        - median

    iaq:
      name: “BME688 IAQ”
      icon: "mdi:approximately-equal"
      filters:
        - median
2

Hx711 doesn’t have I2C interface (except you have some weird module with translator). So it’s not supported through TCA9548A.

indentation is incorrect, temperature (and others) should be in line with platform

3

Thank you for the response, I’ll try with the indentation correction for the bme688.
This is the hx711 amplifier module I have. http://www.handsontec.com/dataspecs/module/HX711.pdf
It has the 4 pins: Gnd, VCC, Data, SCK… so that is not I2C?
Thanks.

4

No it’s not.

5

Thanks again for the clarification. I removed the indentation to be in line with platform, and instead I get the following error:

INFO ESPHome 2025.6.0-dev
INFO Reading configuration /config/esphome/wifihivescale.yaml…
ERROR Error while reading config: Invalid YAML syntax:

mapping values are not allowed here
in “/config/esphome/wifihivescale.yaml”, line 76, column 7

line 76 reads: id: “bme688_hive33”

If I switch line 76 with 77 (i2c_id: multiplex0channel1), I get the same error.
If mapping values are not allowed there, where do I specify the multiplexer channel #?

Here’s the updated yaml:

esphome:
  name: wifihivescale
  friendly_name: WifiHiveScale

esp32:
  board: esp32dev
  framework:
    type: arduino

# Enable logging
logger:

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

ota:
  - platform: esphome
    password: "xxxx"

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

i2c:
  id: i2c0
  sda: 15
  scl: 27
  scan: true


tca9548a:
  - address: 0x70
    id: multiplex0
    i2c_id: i2c0
    channels:
      - bus_id: multiplex0channel0
        channel: 0
      - bus_id: multiplex0channel1
        channel: 1
      - bus_id: multiplex0channel2
        channel: 2
      - bus_id: multiplex0channel3
        channel: 3
      - bus_id: multiplex0channel4
        channel: 4
      - bus_id: multiplex0channel5
        channel: 5
      - bus_id: multiplex0channel6
        channel: 6
      - bus_id: multiplex0channel7
        channel: 7
  
bme68x_bsec2_i2c:
  model: bme688
  sample_rate: ULP
  state_save_interval: 6h
    

# Individual I2C Devices
sensor:
- platform: bme68x_bsec2
    id: "bme688_hive33"
    i2c_id: multiplex0channel1
    #bme688_bsec_id: bme688_bsec
    
  temperature:
    name: "Hive 33 Temp"
    id: hive33_temperature
    sample_rate: ULP
    filters:
      - median

  humidity:
    name: "Hive 33 Humidity"
    id: hive33_humidity
    sample_rate: ULP
    filters:
      - median

  pressure:
    name: "Hive 33 Pressure"
    id: hive33_pressure
    icon: "mdi:gauge"
    sample_rate: ULP
    filters:
      - median

  gas_resistance: # in ohms
    name: "Hive 33 Gas Resistance"
    id: hive33_gas_resistance
    icon: "mdi:omega"
    filters:
      - median

  iaq:
    name: “BME688 IAQ”
    icon: "mdi:approximately-equal"
    filters:
      - median
    
  iaq_accuracy: #IAQ accuracy as a numeric value of 0, 1, 2, 3
    name: “BME688 Numeric IAQ Accuracy”
      
  co2_equivalent: #CO2 equivalent in ppm
    name: “CO2 Equivalent”
    icon: "mdi:molecule-co2"
    filters:
      - median
6

No quotes needed here.
Look, I’m happy to help but I’m not T9.

7

Thanks for your help. I’ve tried without quotes too, still get the msg: ‘mapping values are not allowed here’.

8

Thanks. With your help and a few more indentation corrections, I think I’m good now. Thank you for your help.

9

Great!

PITA at the best…