Category: Allgemein

I bought a rain gauge from china, just google “rain gauge sensor aliexpress” for the product, it was round about 15€.

For my test-setup, I simply cut off the connector and connected the wires directly to GND and GPIO4 and used the internal pull-up resistor:

Adding it to esphome is straight forward and easy. I’m using the pulse counter component, it can use the pulse counter peripheral of the ESP32 and can work in standby-modes:

substitutions:
  update_interval: 5s

sensors:
 - platform: pulse_counter
    name: "Rainfall Pulse Counter"
    id: rainfall_pulse_counter
    use_pcnt: true
    count_mode: 
      falling_edge: INCREMENT
      rising_edge: DISABLE
    pin:
      number: GPIO4
      inverted: true
      mode:
        input: true
        pullup: true
    unit_of_measurement: "mm"
    icon: "mdi:water"
    update_interval: ${update_interval}
    filters:
      - multiply: 0.367
      - debounce: 10ms
    total:
      name: "Rainfall Total Pulses"

The value “0.367” is explained here:
https://community.home-assistant.io/t/how-to-measure-integration-of-rain-pulse-counter-into-daily-value/136709

Then I created two utility meters that convert it to a daily and hourly basis within homeassistant like this:

I built two bee-hive scales according to the great instructions of the Beelogger project.

Remarks:

• I used the “2 holes per side”-variant of the Load Cell Sensor (CZL601 instead of the CZL601-AC), it works fine too.

In my test-setup I connected it like this:

NOTE: Do not use this wiring in production. It’s suitable for testing purposes only.
The HX711-breakout-boards do not work as intended when powered with 3.3V.
For details, see https://community.hiveeyes.org/t/stromversorgung-hx711/893/16

There are 2 possible solutions for this problem, I don’t know yet which way to go:

• exchanging some resistors on the hx711-breakout-board
• use another breakout board that doesn’t cause that much problems, I ordered a NAU7802-breakout-board for testing.

For calibrating, I used weight-lifting weights.

The code for esphome to use it:

substitutions:
  update_interval: 5s

sensor:
  - platform: hx711
    name: "HX711 Weight"
    dout_pin: GPIO4
    clk_pin: GPIO5
    gain: 128
    update_interval: ${update_interval}
    filters:
      - calibrate_linear:
          datapoints:
          # measuring at 25 °C
          -  77915  -> 0
          -  167520 -> 4.08    # empty super + tension belt
          -  205782 -> 5.88    # super with empty frames + tension belt
          -  308103 -> 9.08    # super with empty frames + tension belt + 5kg
          -  413973 -> 14.08   # super with empty frames + tension belt + 10kg
          -  517992 -> 19.08   # super with empty frames + tension belt + 15kg
          -  630596 -> 24.08   # super with empty frames + tension belt + 20kg
          -  734680 -> 29.08   # super with empty frames + tension belt + 25kg
          -  836741 -> 34.08   # super with empty frames + tension belt + 30kg
          -  939262 -> 39.08   # super with empty frames + tension belt + 35kg
          - 1047388 -> 44.08   # super with empty frames + tension belt + 40kg
          - 1149025 -> 49.08   # super with empty frames + tension belt + 45kg
          - 1251903 -> 54.08   # super with empty frames + tension belt + 50kg
          - 1353236 -> 59.08   # super with empty frames + tension belt + 55kg
          - 1450079 -> 64.08   # super with empty frames + tension belt + 60kg
          - 1554032 -> 69.08   # super with empty frames + tension belt + 65kg
          - 1655332 -> 74.08   # super with empty frames + tension belt + 70kg
      - clamp:
          min_value: 0
          ignore_out_of_range: true

Compensating the temperature drift of the scale is still an open TODO.

I’m still unsure which sensors to use in production, so I started experimenting:

I connected a bmp085, a waterproof bh1750, a Si7021 and a bme280 via I2C. Two DS18B20s that will be built in in the lid of the hive and into its center are connected via 1-wire.

In my test-setup, I connected it like this:

The code I used for the sensors:

substitutions:
  update_interval: 5s
  
i2c:
  sda: GPIO35
  scl: GPIO36
  scan: true

one_wire:
  - platform: gpio
    pin: GPIO04

sensor:
  - platform: htu21d
    model: SI7021
    temperature:
      name: "SI7021 Temperature"
    humidity:
      name: "SI7021 Humidity"
    heater:
      name: "SI7021 Heater"
    address: 0x40
    update_interval: ${update_interval}
  - platform: bmp085
    temperature:
      name: "BMP085 Temperature"
    pressure:
      name: "BMP085 Pressure"
    address: 0x77
    update_interval: ${update_interval}
  - platform: bme280_i2c
    temperature:
      name: "BME280 Temperature"
    pressure:
      name: "BME280 Pressure"
    humidity:
      name: "BME280 Humidity"
    address: 0x76
    update_interval: ${update_interval}
  - platform: dallas_temp
    name: "DS18B20 Temperature 1"
    address: 0xcb000000513fb228
    update_interval: ${update_interval}
  - platform: dallas_temp
    name: "DS18B20 Temperature 2"
    address: 0x6f000000bcc72128
    update_interval: ${update_interval}
  - platform: bh1750
    name: "BH1750 Illuminance"
    address: 0x23
    update_interval: ${update_interval}

The Beelogger project is really great.

But: Since my house is automated with homeassistant, esphome, a lot of ESP32s and my bee-hives are in WIFI-range, I decided to rebuild the beelogger-functionality on esphome basis.

Additional arguments for realizing it with an ESP32 instead of an Arduino or STM32 might be:

• more CPU power
• more RAM & flash (up to 8 MB RAM & 16 MB flash)
• integrated WIFI
• probably less power consumption when using deep sleep modes
• A DSP for audio analysis
• more ADCs with higher resolution (depending on the ESP32 variant used)
• a built-in RTC
• the comfort of esphome:
  • OTA updates
  • a built-in automated connection to homeassistant
  • a webinterface on the device
  • no complex sketches to maintain, just a .yaml-config

Desicion: I’m going to use an ESP32-S3-N16R8

It provides:

• a dual-core 32-bit microprocessor with 240 MHz
• 8MB of additional PSRAM and 16MB flash,
• 2.4 GHz Wi-Fi (IEEE 802.11b/g/n) and Bluetooth® 5 (LE)
• An hardware RTC
• Two general-purpose SPI ports
• Three UARTs
• Two I2Cs
• Two I2Ss
• Pulse counter
• Two 12-bit SAR ADCs, up to 20 channels
• Four 54-bit general-purpose timers
• 52-bit system timer
• Three watchdog timers
• DSP-hardware
• Four power modes designed for typical scenarios: Active, Modem-sleep, Light-sleep, Deep-sleep
• A lot of GPIOs 🙂

It’s the currently most powerfull ESP32, its hardware should be more than enough for the task 😀

Realizing it will be a major project, but probably also a lot of fun 🙂

The TODOs I see so far, I’ll realize them in single test projects:

• get all the desired sensors working properly
• write an external component for esphome for the audio-analysis
• write a component for esphome for the bee counter hardware
• write a component for esphome to connect to the beelogger-server
• care about the power management
• logging to SD-card/flash
• properly wiring it all up at the end, making it electronically fail safe, soldering it onto a prototype-board
• install everything in proper cases with proper connectors and install it in a bee hive
• realize additional ideas, they will for sure come up when working on this project 😉