Is VEML7700 Ambient Light Lux Sensor Compatible with Home Assistant (ESPHome)?
Electrical Specifications
Always confirm pin assignments against the manufacturer datasheet before wiring.
Compatibility Overview
High-accuracy 16-bit digital ambient light sensor measuring lux levels up to 120000 lx for solar tracking.
Wiring VEML7700 Ambient Light Lux Sensor to ESP32
| Module pin | ESP32 | Note |
|---|---|---|
| VIN | 3V3 | Adafruit-style breakouts accept 3–5V; the sensor itself is a 3.3V part. |
| GND | GND | |
| SDA | GPIO21 | |
| SCL | GPIO22 |
Host pins are the ones the configuration on this page uses. Move a pin here and change it in the YAML — they are documented together so they cannot disagree.
Technical Specification Matrix
| Feature / Attribute | Specification / Status |
|---|---|
| Hardware Protocol | I2C Bus / 3.3V |
| Bridge Required | NO |
| Border Router Needed | None |
| Hardware Capabilities & Peripherals | Illuminance (Lux) White Light Level Note: these entities come from the ESPHome configuration you flash — each one needs its matching component in that YAML before it appears. |
| Pairing Complexity | Plug-and-Play |
| Factory Reset Instruction | Hold BOOT button for 3s. |
Wire, Flash, Adopt, Check
Wire it up
Follow the wiring table above. The ESP32 pins there are the ones the configuration uses, so if you move one, change it in both places.
Flash the configuration
Create a new device in the ESPHome dashboard (the Home Assistant add-on) and paste the configuration below into it, or save it as emb_esp32_veml7700_ha.yaml and run esphome run emb_esp32_veml7700_ha.yaml. The first flash goes over USB. If it is not detected, hold BOOT button for 3s to put it in download mode. Every update after that is over the air.
Adopt it in Home Assistant
Settings → Devices & Services. A node on the same network shows up as a discovered ESPHome device within a minute of joining Wi-Fi; choose Configure and enter the API encryption key from your secrets.yaml. If discovery does not find it, add the ESPHome integration by hand with the node's IP address.
Check it works
The I2C scan at boot lists 0x10 and Illuminance in Home Assistant tracks a hand over the sensor. A value stuck at the top of the range is the sensor saturated with auto mode off.
ESPHome Configuration
Starting configuration for VEML7700 Ambient Light Lux Sensor on ESP32. Untested on hardware — verify wiring and pins against your own board.
# ESPHome configuration for VEML7700 Ambient Light Lux Sensor
# Host: ESP32. Pin numbers below are host-side defaults — any free
# GPIO will do, and you should change them to match your own wiring.
esphome:
name: emb_esp32_veml7700_ha
friendly_name: "VEML7700 Ambient Light Lux Sensor"
esp32:
board: esp32dev
framework:
type: esp-idf
logger:
api:
encryption:
key: !secret api_encryption_key
ota:
- platform: esphome
password: !secret ota_password
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
i2c:
id: i2c_main
sda: GPIO21
scl: GPIO22
scan: true
sensor:
- platform: veml7700
address: 0x10
ambient_light:
name: "Illuminance"
update_interval: 60s
Before you flash:
the !secret values come from your
secrets.yaml, and the GPIO numbers are host-side
defaults rather than properties of this part — change them to match how you actually wired it.
If the device is not found:
it is usually the I2C address, not the config. Many breakouts strap their address with
solder jumpers, so two boards of the same part can differ. This config leaves
scan: true on — the boot log lists every address
actually present on the bus, and you can copy the right one from there.
What Appears in Home Assistant
Lux, with device class illuminance. The platform also offers white, infrared and the raw counts, plus the gain and integration time it settled on, if you add them.
Known Problems and Fixes
One address, no strap
The VEML7700 is fixed at 0x10. Two on one bus need a multiplexer.
Leave auto mode on
The range from 0.005 to 120,000 lux comes from the sensor switching gain and integration time as light changes, which the component does by default. Pinning them is only for fast-changing light, and saturates at one end or the other.
What it points at is what it reads
The field of view is wide. Behind a window it reads the sky; on a desk it reads the ceiling light. For "is the room dark" it wants to look into the room; for "is it daytime" it wants to look out.
Glass and diffusers scale the reading
Tinted glass or a diffuser in front of the sensor cuts the number by a fixed fraction. A multiply filter calibrated against a lux meter — or a phone app in a pinch — corrects it.
Update rate for automations
The 60s in the config is right for logging. Lights that should react to a cloud passing want 5–10s.
Report a Pinout Error or Submit Tested Code Snippets
Found a pin mapping quirk or built a custom ESPHome YAML driver for VEML7700 Ambient Light Lux Sensor? Submit a pull request or report corrections to our index.
Hardware Correction Reporter (emb-esp32-veml7700-ha)
Frequently Asked Questions
Does VEML7700 Ambient Light Lux Sensor work without an internet connection?
How is VEML7700 Ambient Light Lux Sensor powered and wired to the host board?
How does the host board reach Home Assistant (ESPHome)?
Alternatives
BH1750 Ambient Light Sensor
Cheaper, 65,000 lux ceiling, and a strappable address.
TSL2591 HDR Ambient Lux Sensor
Wider dynamic range with an infrared channel.
MAX44009 Wide-Range Lux Sensor
Similar range in a smaller, lower-power package.
LTR390 UV & Ambient Light Sensor
Adds a UV index channel.
TCA9548A 8-Channel I2C Multiplexer
The multiplexer that lets several fixed-address sensors like this one share a bus.