Introduction

The SCD40 Breakout Board is a compact PCB kit featuring the SCD40, making it easy to add CO₂ monitoring to any new or existing project.

Please go to this website and copy the randomly generated API key inside the code block as shown below then paste it in the code below where you see "use-a-randomly-generated-key-here".

GPIO Pins Listed:

#These are the i2c pins
i2c:
  sda: GPIO1
  scl: GPIO0

#This is the onboard LED pin
GPIO3

The Apollo DEV-2 is an ideal starter board for tinkerers, available on its own or bundled with a breadboard and Dupont (jumper) wires. The example YAML below uses the DEV-2 (ESP32 C6 Mini 4MB flash or 8MB flash if newest revision).

Example ESPHome yaml:

#Define Project
substitutions:
  name: scd40-breakout-board
  version:  "1"
  device_description: ${name} made by Apollo Automation - version ${version}.

esphome:
  name: "${name}"
  friendly_name: SCD40 Breakout Board
  comment: SCD40-Breakout-Board With Apollo DEV-2
#  platformio_options:
#    board_build.flash_mode: dio

  project:
    name: "ApolloAutomation.DEV-2"
    version: "${version}"

# Define Board
esp32:
  board: esp32-c6-devkitc-1
  framework:
    type: esp-idf

# Enable logging
logger:

# Enable Home Assistant API
api:
  encryption:
    key: "use-a-randomly-generated-key-here"
  actions:
    #Co2 Calibration Action
    - action: calibrate_co2_value
      variables:
        co2_ppm: float
      then:
        - scd4x.perform_forced_calibration:
            value: !lambda "return co2_ppm;"
            id: scd40
  reboot_timeout: 0s

ota:
  - platform: esphome
    password: "a53d93acd493275512730c776f88722a"

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

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Apollo-Dev-2 Fallback Hotspot"
    password: !secret wifi_password

captive_portal:

web_server:
  port: 80
  version: 3

i2c:
  sda: GPIO1
  scl: GPIO0
  id: bus_a

#onboard LED using pin GPIO3 as shown below
light:
  - platform: esp32_rmt_led_strip
    id: rgb_onboard_light
    name: "RGB Onboard Light"
    pin: GPIO3
    default_transition_length: 0s
    chipset: WS2812
    num_leds: 1
    rgb_order: grb
    effects:
      - pulse:
          name: "Slow Pulse"
          transition_length: 1000ms
          update_interval: 1000ms
          min_brightness: 50%
          max_brightness: 100%
      - pulse:
          name: "Fast Pulse"
          transition_length: 100ms
          update_interval: 100ms
          min_brightness: 50%
          max_brightness: 100%

button:
  - platform: restart
    icon: mdi:power-cycle
    name: "ESP Reboot"

  - platform: factory_reset
    disabled_by_default: True
    name: "Factory Reset ESP"
    id: factory_reset_all

  - platform: template
    name: "Calibrate SCD40 To 420ppm"
    id: set_SCD40_calibrate
    on_press:
      - scd4x.perform_forced_calibration:
          value: 420
          id: scd40

sensor:
  - platform: internal_temperature
    name: "ESP Temperature"
    id: sys_esp_temperature

  - platform: uptime
    name: Uptime
    id: sys_uptime
    update_interval: 60s

  - platform: wifi_signal
    name: RSSI
    id: wifi_signal_db
    update_interval: 60s
    entity_category: "diagnostic"

  - platform: scd4x
    id: scd40
    co2:
      name: "CO2"
      id: "co2"
    automatic_self_calibration: false
    update_interval: 60s
    measurement_mode: "periodic"
    i2c_id: bus_a

  - platform: wifi_info
    ip_address:
      name: "${name} IP"
      icon: "mdi:ip-outline"