Install the ESPHome addon to HA.
Buy an esp8266 or esp32 board. You can also buy a smaller esp D1 mini.
Buy the BH1750 sensor.
You will need a USB cable to connect esp and HA to be able to upload yaml to esp.
Then look here
If you don’t know how to connect and add a new device, write.
Thanks so much! Is there any difference between those options as far as ease of use? Or do you have a favorite?
This BH1750 sensor comes with a fresnel lens and the required connecting cables. 3-D print a small rectangle box with a hole in top (typically for IR motion sensor) and you’re good to go.
If you want to avoid soldering (cheapest path for <$5 in total) you might work’a’round that choosing more expensive versions with some connector system like Qwiic for example 
https://community.home-assistant.io/t/outdoor-lux-sensor/421926
I used the same sensor as recommend by FredTheFrog, though I got it from Aliexpress.
Hey All,
I am giving this project a shot and have a working ESP32 (as a bluetooth proxy) but need a little help with the pinout connections. There is a video online but it uses a different ESP32 and it looks like although the pinout from mine is pretty standard it’s not clear which are the right ones for using the ambient sensor. Here is a picture of the chip and codes. Any help is appreciated.
Thanks Tom!
This is a really good project for learning ESPHome and working with an ESP prototype board. You can use any ESP board. My board of choice is the Wemos D1 Mini. They are cheap and I buy them usually from AliExpress five at a time.
If you would rather take a shortcut, Screek Workshop | eBay Stores has one for under $11, and it has ESPHome already installed.
So when I add these relevant parts to my config.yaml file, I get these errors from the Developer Tools configuration checker
Configuration warnings
Platform error ‘sensor’ from integration ‘bh1750’ - Integration ‘bh1750’ not found. Integration error: i2c - Integration ‘i2c’ not found.
Am I doing something wrong or do I just need to reboot for the configuration to load and turn on the ESP32?
OPPS…hope I did not burn something out as I had plugged it in…got them reversed to the right position thank you for correcting me!
Please don’t post pictures of text. Post the actual text and format it for the forum: https://community.home-assistant.io/t/how-to-help-us-help-you-or-how-to-ask-a-good-question/114371#oneone-format-it-properly-16
We need you entire sensor: section at least.
Sensor should be ok with reverse polarity.
Sorry about the picture of text was trying to make sure I did not put any sensitive information in the post but I looked through my config file and it has nothing sensitive so here is my whole config if that helps?
default_config:
frontend:
themes: !include_dir_merge_named themes
extra_module_url:
- /local/card-mod.js
automation: !include automations.yaml
script: !include scripts.yaml
scene: !include scenes.yaml
input_number:
dual_thermostat_target:
name: Dual Thermostat Target Temperature
min: 50 # Adjust the min and max values as needed
max: 90
step: 1
i2c:
sda: 21
scl: 22
scan: true
id: bus_a
sensor:
platform: template
sensors:
family_room_average:
friendly_name: “Family Room Average”
unit_of_measurement: “°F”
value_template: >-
{{
(states(‘sensor.nest_ac_heat_temperature’) | float +
states(‘sensor.family_dot_new_temperature’) | float) / 2 | round(2)
}}
bedroom_average:
friendly_name: “Bedroom Average”
unit_of_measurement: “°F”
value_template: >-
{{
(states(‘sensor.primary_bedroom_dot_temperature’) | float +
states(‘sensor.leak_sensor_temperature’) | float) / 2 | round(2)
}}
housewide_temperature:
friendly_name: “Housewide Temperature”
unit_of_measurement: “°F”
value_template: >-
{{
(states(‘sensor.family_room_average’) | float * 0.75 +
states(‘sensor.bedroom_average’) | float * 0.25) | round(2)
}}
nest_ac_heat_temperature:
friendly_name: “Nest-House Temperature”
unit_of_measurement: “°F”
value_template: “{{ states(‘climate.nest_ac_heat’) | float }}”
mini_split_bedroom_temperature:
friendly_name: “Mini Split-BedRm Temperature”
unit_of_measurement: “°F”
value_template: “{{ states(‘climate.30786325850206_climate’) | float }}”
platform: weatheralerts
state: FL
zone: 160
county: 115
platform: noaa_tides
station_id: 8725889
unit_system: english
platform: bh1750
name: “BH1750 Illuminance”
address: 0x23
update_interval: 60s
homeassistant:
packages: !include_dir_named packages
input_select:
dual_thermostat_mode:
name: Dual Thermostat Mode
options:
- Heat
- Cool
- Off
initial: Heat # Set the initial mode as desired
icon: mdi:thermostat
input_boolean:
bathroom_toilet_switch:
name: Bathroom Toilet Switch
initial: off
cloud:
PS…I got a warning about formatting it for forum but not sure how to do that?
I told you how:
However, It appears you are adding this to your configuration.yaml file. That is not where the config goes. It goes in its own file in the config/esphome folder. Each ESPHome device gets its own file there. Please have a read of this:
Thanks Tom,
Very helpful I will read up. I am learning a lot! one of my longer-term goals is to use this knowledge to hook up a sensor through ESPhome that uses radar to determine water levels to make a tide gauge for my dock that reads the tide level and digging in here is a really good start.
I installed ESPHome add on as described and since I already had my ESP working as a bluetooth proxy it picked it up already with some entries in the config file for that esp32. I then modified it’s yaml configuration file by adding in what I tried adding before and used the verify function of ESP to make sure it was not going to cause problems (it said there were problems with some of my ISC settings so I stripped those out since I had them as the original defaults anyway so they were technically redundant. I saved the yaml and verified it’s in the correct configuration file within ESPHome as previously described. When I ran the “install” it worked, but did generate an error at the end although the yaml was added when I checked manually by the file editor. Inside HA, I could not find any entities created with the new configuration but perhaps that’s not the anticipated behavior? And perhaps I need to use this ESP as dedicated to this light sensor OR am I correct that I can use it this way both as a bluetooth proxy AND as an ambient light sensor? Once I get one running, my goal will be to get several ESPs anyway to sense light levels in various rooms. Also note in the code posted below I removed the key not sure that’s something that should be public but it’s there as it should be. Here’s the config code wrapped, my additions were at the very end.
substitutions:
name: esp32-bluetooth-proxy-9670cc
friendly_name: Bluetooth Proxy 9670cc
packages:
esphome.bluetooth-proxy: github://esphome/firmware/bluetooth-proxy/esp32-generic.yaml@main
esphome:
name: ${name}
name_add_mac_suffix: false
friendly_name: ${friendly_name}
api:
encryption:
key: [actualkeyhidden]
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
i2c:
sensor:
- platform: bh1750
name: "BH1750 Illuminance"
address: 0x23
update_interval: 60s
You need to tell us what the error was. All the HA mind readers were killed in the great pogrom of 2020.