RoomsenseIQ on ESPHome

ESPHome configuration that runs a RoomsenseIQ ESP32-S3 environmental monitor as a pure ESPHome device, reimplementing the stock firmware's sensor calibration, math, and on-device behaviour (RGB status LED, calibration flows). The stock ESP-IDF firmware is treated as the spec of truth; every non-obvious value is annotated with the stock source line it mirrors.

What it measures

• Temperature & humidity - SCD4x
• CO2 - SCD4x (with one-tap forced recalibration)
• VOC & NOx indices - SGP4x
• Particulate matter (PM1.0 / PM2.5 / PM10) - MPM10 (custom component)
• Carbon monoxide - TGS5141 (ADC, see Notes)
• Ambient light - photoresistor
• Presence / occupancy - LD2410 mmWave radar
• Motion - IRA-S210ST01 PIR
• Dew point + mold risk - derived from SCD4x (Magnus formula, stock parity)

On-device behaviour (ported from stock firmware)

• Occupancy fusion - PIR + radar state machine with a BedSense mode (radar-only) and NVS-persisted latched state.
• Direction detection - towards/away movement from radar distance deltas with stock hysteresis, suppressed in the radar's unreliable close range.
• LD2410 auto-calibration - baseline ("empty room") and blindspot ("worst spot occupied") buttons that sample per-gate energies and write the radar thresholds, mirroring the stock calibration tasks.
• Air-quality LED alerts - a 5 s loop drives the status light off stock pollutant thresholds (CO2 / VOC / PM / mold), layered over the occupancy state, with a distinct calibration indication.
• CO2 forced calibration - one-tap button that runs the stock 3-minute fresh-air dwell, performs the FRC at 421 ppm, and records the calibration date as a diagnostic sensor.

Status LED states

State	Appearance
Occupied	steady orange
Vacant	steady blue
Elevated air pollution	yellow strobe
Extreme air pollution	purple strobe
CO2 calibrating	cyan strobe
Wi-Fi disconnected	orange/blue alternating

All effect values are stock PWM duties (gamma correction disabled to keep them faithful).

Hardware

ESP32-S3 (esp32-s3-devkitc-1, esp-idf framework). I²C bus on sda: GPIO12, scl: GPIO13. Sensors: SCD4x, SGP4x, MPM10, TGS5141, LD2410, IRA-S210ST01, RGB status LED, photoresistor.

Configuration structure

These YAML files are package fragments, not full device configs - each is self-contained and meant to be included remotely as an ESPHome package.

• roomsense-base.yaml - base device: bluetooth_proxy, web_server, I²C, and the presence/motion/light/LED stack. Pulls in components/{ld2410, ld2410-calibration, ira-s210st01, direction-detection, occupancy, ambient-light, rgb-led}.yaml.
• climatesense.yaml - ClimateSense expansion board: environmental sensors. Pulls in components/{mpm10, scd4x, sgp4x, tgs5141, air-quality-alerts, status-led}.yaml.
• components/*.yaml - one fragment per sensor/feature.
• components/debug.yaml - debug settings.

Why not stock firmware?

The devices make great Bluetooth proxies, and ESPHome makes that trivial. Beyond that, the stock firmware has some rough edges:

• Devices show up in Home Assistant as one device with a flat set of sensors (roomsense/firmware#13).
• The setup access point keeps broadcasting with its default password even after Wi-Fi connects (roomsense/firmware#1).
• No firmware updates since Sep 2024.

Installation

The device flashes over USB like any other ESP32. Because these files are package fragments, include them from your own device config:

esphome:
  name: roomsense-iq-office
  friendly_name: RoomsenseIQ Office
  name_add_mac_suffix: true

esp32:
  board: esp32-s3-devkitc-1
  variant: esp32s3
  framework:
    type: esp-idf

packages:
  # your own shared config
  wifi: !include common/wifi.yaml

  RoomsenseIQ:
    url: https://github.com/talmuth/RoomsenseIQ_Esphome
    # base device only:
    files: [roomsense-base.yaml]
    # or base + ClimateSense expansion board:
    # files: [roomsense-base.yaml, climatesense.yaml]
    # or specific fragments only:
    # files: [components/mpm10.yaml, components/debug.yaml]

Notes

The ClimateSense CO sensor (TGS5141) is on GPIO20 (ADC2).

On esphome 2025.8.0 and newer it builds and runs with Wi-Fi enabled out of the box, no patch needed: the ESP-IDF v5 ADC rewrite (esphome#9021) dropped the old "ESP32S3 doesn't support ADC on this pin when Wi-Fi is configured" restriction (the final_validate_config check no longer exists in the ADC component).

On esphome older than 2025.8.0 that check rejects the build:

sensor.adc: [source .../components/tgs5141.yaml:2]
    ESP32S3 doesn't support ADC on this pin when Wi-Fi is configured.

Either omit components/tgs5141.yaml, or patch final_validate_config in your esphome install's esphome/components/adc/sensor.py to whitelist GPIO20:

diff --git a/esphome/components/adc/sensor.py b/esphome/components/adc/sensor.py
index 3309bd04..f39ff3a8 100644
--- a/esphome/components/adc/sensor.py
+++ b/esphome/components/adc/sensor.py
@@ -64,6 +64,7 @@ def final_validate_config(config):
                         CONF_WIFI in fv.full_config.get()
                         and config[CONF_PIN][CONF_NUMBER]
                         in ESP32_VARIANT_ADC2_PIN_TO_CHANNEL[variant]
+            and not (variant == "ESP32S3" and config[CONF_PIN][CONF_NUMBER] == 20)
                 ):
                         raise cv.Invalid(
                                 f"{variant} doesn't support ADC on this pin when Wi-Fi is configured"

Support

If this is useful, you can buy me a coffee.