An oven-area monitor built with ESPHome on an ESP32-C6.

The goal is to answer simple questions like:

• Is the oven likely running?
• Is it cooling down?
• Is it off?
• Is there a possible gas leak?
• Is the oven running while nobody is in the kitchen?

The goal is not to measure exact oven temperature.

This project uses:

• SHT3x to monitor temperature near the oven
• MQ-6 to monitor possible gas leakage
• Home Assistant to provide room temperature and motion state
• Home Assistant automations to send alerts

• Reads oven-area temperature from SHT3x
• Reads MQ-6 analog value for a rough gas trend
• Reads MQ-6 digital alert output
• Calculates temperature change over 5 minutes
• Compares oven-area temperature with room temperature from Home Assistant
• Exposes one text status sensor:
  • Pending
  • Off
  • Running
  • Cooling
• Uses Home Assistant automation to send alerts for:
  • oven status changes
  • gas alert detection
  • MQ-6 analog threshold
  • oven running while kitchen motion conditions match the automation logic

The SHT3x reads the temperature near the oven.

Every minute, the project stores a new reading and keeps the last 5 minutes of values.
It then calculates the difference between:

• current oven temperature
• oven temperature 5 minutes ago

That gives a simple Temp Change 5 Min value.

The project also reads the room temperature from Home Assistant using:

• sensor.kitchen_temperature

The oven status is then decided like this:

• Pending
  • not enough samples collected yet
• Off
  • oven-area temperature is close to room temperature
• Running
  • temperature is rising strongly, or the oven is still clearly hotter than room temperature
• Cooling
  • oven was running and is now cooling down

The MQ-6 is used in 2 ways:

• AO, analog output, as a rough gas trend
• DO, digital output, as a gas alert signal

The analog value is useful for thresholds and graphs.
The digital output is useful for simple immediate alerts.

This project also uses Home Assistant automation for notifications.

The automation can alert you when:

• oven status changes
• gas alert is detected
• MQ-6 analog value goes above a threshold
• the oven is reported as running while the kitchen motion condition in Home Assistant matches your rule

In this setup, kitchen presence is based on a motion sensor exposed in Home Assistant.

The automation YAML is stored separately in the repository and is not embedded in this README.

This project is useful for:

• home automation
• notifications
• trend monitoring
• extra warning

It should not be your only gas safety system.

For real kitchen gas safety, use a proper certified gas alarm.

• 1 × ESP32-C6 dev board
• 1 × SHT3x I2C sensor module
• 1 × MQ-6 gas sensor module
• 2 × 10k resistors
• 2 × 20k resistors
• jumper wires
• breadboard, perfboard, or soldered board

Connect the SHT3x like this:

Important: power the SHT3x from 3.3V, not 5V.

The MQ-6 module has:

• VCC
• GND
• AO
• DO

Connect AO to GPIO4 through a resistor divider:

MQ-6 AO ---- 10k ----+---- GPIO4
                     |
                    20k
                     |
                    GND

Connect DO to GPIO5 through a resistor divider:

MQ-6 DO ---- 10k ----+---- GPIO5
                     |
                    20k
                     |
                    GND

AO and DO are separate signals. Do not connect them together.

                           +----------------------+
                           |      ESP32-C6        |
                           |                      |
                           | 3V3 ---------------+------------------> SHT3x VCC
                           | GND ---------------+--------+---------> SHT3x GND
                           |                     \       \
                           |                      -------+---------> MQ-6 GND
                           |                        
                           | 5V -------------------------------> MQ-6 VCC
                           |
                           | GPIO7 ----------------------------> SHT3x SDA
                           | GPIO6 ----------------------------> SHT3x SCL
                           |
                           | GPIO4 <-----+---- 10k ---- MQ-6 AO
                           |             |
                           |            20k
                           |             |
                           |            GND
                           |
                           | GPIO5 <-----+---- 10k ---- MQ-6 DO
                           |             |
                           |            20k
                           |             |
                           |            GND
                           +----------------------+

Think of the MQ-6 AO and DO as two separate resistor dividers.

MQ-6 AO -> 10k -> junction -> GPIO4
                        |
                       20k
                        |
                       GND

MQ-6 DO -> 10k -> junction -> GPIO5
                        |
                       20k
                        |
                       GND

This is the same electrical idea whether you build it on: • breadboard • perfboard • soldered prototype board

The repository includes the ESPHome configuration file separately.

It includes: • SHT3x temperature sensor • MQ-6 analog sensor • MQ-6 digital gas alert • room temperature from Home Assistant • 5-minute temperature delta calculation • oven status logic

This project creates these useful entities:

• sensor.oven_oven_temperature
• sensor.oven_oven_temp_change_5_min

• sensor.oven_mq6_analog
• binary_sensor.oven_mq6_gas_alert

• sensor.oven_status

This project also expects these Home Assistant entities to exist:

• sensor.kitchen_temperature
• a kitchen motion sensor used by your automation logic

The Home Assistant automation in this project is designed to notify you when:

• oven status changes
• gas alert becomes active
• MQ-6 analog value crosses a defined threshold
• oven is running while the kitchen motion logic matches your alert rule

This lets you build practical notifications such as:

• gas warning in the kitchen
• oven status updates
• oven running while nobody is detected in the kitchen
• room temperature unavailable warning

Place the SHT3x:

• near the oven
• away from direct flame
• away from direct contact with metal surfaces
• where it can detect temperature rise around the oven

Place the MQ-6:

• where leaked gas is likely to reach it
• in a location with airflow
• away from grease and steam as much as possible

MQ sensors need warm-up and can drift, so expect some variation.

• Keep all grounds common
• Keep the resistor-divider wiring short and clean
• Verify AO and DO divider voltages with a multimeter before connecting to the ESP32-C6
• Label AO and DO clearly during assembly
• If using a perfboard, test everything first on a breadboard

• VCC to 3V3
• GND to GND
• SDA to GPIO7
• SCL to GPIO6

• VCC to 5V
• GND to GND
• AO to GPIO4 through 10k / 20k
• DO to GPIO5 through 10k / 20k

• device connects to Wi-Fi
• sensor.kitchen_temperature exists in Home Assistant
• oven status changes from Pending to normal states after enough samples

• kitchen motion sensor is available
• notification service is configured
• automation file is imported and enabled

• The MQ-6 analog value is a rough trend, not a calibrated ppm reading
• The MQ-6 digital signal is useful for a simple gas alert
• This project is better used as a smart monitor, not as a certified safety system

Add your preferred license here.

For example:

MIT License