4MiFlora Plant Sensors in Home Assistant

I’ve been suing the MiFlora Home Assist­ant integ­ra­tion to get data on vari­ous house plants for a while. How­ever along the way I’ve had to over­come vari­ous hurdles includ­ing lim­ited range of bluetooth, bat­tery life issues, and get­ting the bat­tery val­ues to report. I finally seem to have cracked all of these and now have a sys­tem that works reli­ably with lots of plants around the house. I’ve sum­mar­ised what I’ve used below.

Hardware

The first thing to say is that I do have a bluetooth USB dongle attached to my home assist­ant sys­tem. This mon­it­ors the plants in range dir­ectly (i.e. the ones in the same room as the HA box). To mon­it­or more dis­tance devices I have used an ESP32 board with built-in bluetooth mod­ule which I have inside a cheap little case and have powered with an old micro-USB phone charger

• USB Dongle: the one I got is no longer avail­able — due to age — but there are plenty of amazon and else­where — just make sure it has sup­port in linux
• ESP32 board: I got a JZK ESP32‑S which is cur­rently £6.49 on amazon
• Case for ESP32: I found the case for a NodeM­CU Wroom-32D (short aer­i­al) fit­ted my board — this was £4.20 from ebay

Integrations for Home Assistant

Whilst the basic MiFlora integ­ra­tion is built in to home assist­ant I found it uses a lot of bat­tery when used nat­ively. Instead I use the Bluetooth Low Energy Mon­it­or 3^rd party integ­ra­tion which you can install eas­ily using HACS
I then also installed the ESPHome integ­ra­tion for home assist­ant to man­age my ESP32 BLE repeater
Finally, to dis­play the plants in a nice way I added a par­tic­u­lar fork of the lovelace plant card addon via HACS

Configuration

Once BLE Mon­it­or was installed and con­figured with my bluetooth dongle it picked up the MiFlora sensors with­in range and lis­ted them in its “devices” drop down as well as list­ing the devices and entit­ies on it’s card in the HA configuration
The great thing about BLE mon­it­or is that it listens for the sensors to trans­mit, rather than act­ively polling them, which would run down their bat­ter­ies. How­ever, the sensors don’t trans­mit bat­tery inform­a­tion so to get this we have to act­ively poll for it. Polling just for this, and pass­ively listen­ing for the oth­er data seems to be the best com­prom­ise if you want to have all the data avail­able but also max­im­ise the sensor’s bat­tery life. I have sep­ar­ated my configuration.yaml into mul­tiple sep­ar­ate files to keep things a bit easi­er to man­age so I just have the fol­low­ing line in my configuration.yaml —

sensor: !include sensors.yaml

Then in sensors.yaml I have each plant lis­ted as follows

 - platform: miflora
   mac: 'mac:address:of:miflora:sensor:here'
   name: basil
   force_update: true
   scan_interval: 08:00
   median: 3
   go_unavailable_timeout: 43200
   monitored_conditions:
     - battery

Next — to make the plants appear nicely I have a plants con­fig. As before a single line in configuration.yaml to start with: 

plant: !include plants.yaml

And then in plants.yaml I have as follows

basil:
  sensors:
    moisture: sensor.ble_moisture_basil
    battery: sensor.basil_battery
    temperature: sensor.ble_temperature_basil
    conductivity: sensor.ble_conductivity_basil
    brightness: sensor.ble_illuminance_basil
  min_battery: 15
  min_brightness: 2500
  max_brightness: 60000
  min_temperature: 8
  max_temperature: 32
  min_moisture: 15
  max_moisture: 60
  min_conductivity: 350
  max_conductivity: 2000

Note the subtle dif­fer­ence between the entity name for the bat­tery com­pared with the oth­er sensors. The bat­tery entity is com­ing from the miflora plat­form in sensors.yaml whilst the oth­er 4 sensors are com­ing from the BLE integ­ra­tion. There IS a bat­tery entity lis­ted by the BLE integ­ra­tion but this just shows as “unknown” for this plant. This con­fig­ur­a­tion is needed for the plant card to show the plant in a nicely presen­ted way
Then simply go to a the place you want to add your plant and add the lovelace plant card. You will have to “con­fig­ure” the card manu­ally, but it only takes 3 lines…

type: custom:flower-card
entity: plant.basil
species: ocimum basilicum

Note that the spe­cies is lis­ted for 2 reas­ons. Firstly it will dis­play the name on the card, but more import­antly, it will also dis­play a pic­ture of the plant if you have down­loaded the plant images and added them into \config\www\images\plants using the lat­in names — the inform­a­tion on the data­base is avail­able on the lovelace plant card documentation

Extending range

Finally, we need to extend the range we can reach. For this we need the ESP32 device. The first thing to do is to get it hooked up to your com­puter via USB and flash it with a basic ESPHome image
I used the ESPHome Flash­er and the cp210x uni­ver­sal win­dows driver from SiL­abs and fol­lowed the guide provided by the ESPHome Home­As­sist­ant integration
The con­fig I used for my ESP32 device is below

esphome:
  name: jzk-esp-32s
  platform: ESP32
  board: esp32doit-devkit-v1

# Enable logging
logger:

# Enable Home Assistant API
api:

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

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Esp32 Fallback Hotspot"
    password: "random-password-here"
    
external_components:
  - source: github://myhomeiot/esphome-components
    
esp32_ble_tracker:
    
ble_gateway:
  devices:
    - mac_address: mac:address:of:miflora:sensor:to:monitor:goes:here
  on_ble_advertise:
    then:
      homeassistant.event:
        event: esphome.on_ble_advertise
        data:
          packet: !lambda return packet;
          
myhomeiot_ble_host:

myhomeiot_ble_client:
  - mac_address: mac:address:of:miflora:sensor:to:monitor:goes:here
    service_uuid: '1204'
    characteristic_uuid: '1A02'
    update_interval: 4h
    on_value:
      then:
        homeassistant.event:
          event: esphome.on_ble_advertise
          data:
            packet: !lambda |-
              if (x.size()  2)
              {
                ESP_LOGE("myhomeiot_ble_client", "payload has wrong size (%d)", x.size());
                return "";
              };
              ESP_LOGI("myhomeiot_ble_client", "Battery (%d%%), firmware (%s)", x[0], std::string(x.begin(), x.end()).substr(2).c_str());
              char buffer[70 + 1];
              const uint8_t *remote_bda = xthis.remote_bda();
              snprintf(buffer, sizeof(buffer), "043E2002010000%02X%02X%02X%02X%02X%02X14020106030295FE0C1695FE41209800000A1001%02X00",
                remote_bda[5], remote_bda[4], remote_bda[3], remote_bda[2], remote_bda[1], remote_bda[0], x[0]);
              return std::string(buffer).c_str();

Then save and update to your esp32 device via wifi. The ESP32 device will pick up the data from the miflora sensor and will ‘push’ it via wifi to the BLE integ­ra­tion which will cre­ate a device and entit­ies auto­mat­ic­ally. Devices pushed in this way do appear to show their bat­teyr level (thanks to the code at the bot­tom of the myhomeiot_ble_client sec­tion I believe). You then just need to give the device a nice name (and let the entit­ies be renamed too) and then cre­ate an entry in plants.yaml with the right entities