NodeMCU and BME280 Humidor Hygrometer - Thin Ribbon Wires/Cables for humidor monitor

Hi! I’m trying to come up with a way to get wires to the inside of my desktop humidor without drilling holes or modifying the humidor. I plan to use a NodeMCU with a DHT sensor.

Im thinking about affixing the NodeMCU in a small project box to the outside back of the humi, then run the ribbon wires from the NodeMCU through to the DHT sensor on the inside and use some double sided tape to secure the sensor to the underside of the lid. Allowing the wires to get shut in the lid, hence the need for extremely thin wires.

Is anyone aware of any “paper thin” ribbon wires (and where to look) that can be used for something like this. Ive done a fair amount of searching but keep coming up short.

Thank you for any and all help!

Wire wrap wires are hair thin. Or use a flexible PCB.

However don’t use a DHT inside a humidor. It won’t handle high humidity for more than a few weeks before the reading freezes or otherwise becomes “stuck” as it is saturated. Use a better sensor such as the BME280.

Flexible PCB is just the thing i was looking for! Just couldn’t figure out what to search for.

Good call on the BME280 ill check that one out.

So just a quick follow up for posterity purposes.

I ended up using the following parts to build this;

BME280 Sensors - as @AaronCake mentioned above, these are far superior to the DHT sensor i was thinking about using. I get completely identical RH and Temp readings from this sensor as my regular Humi-care Hygrometer.

20 pin flat fables with breakout boards on both ends. (Please note that 20 pins is way overkill as i only needed 4 pins for the BME280, but i have plans for other projects so i opted to just buy a handful of the 20 pin versions for my stock of parts.)

Cables
https://www.amazon.com/gp/product/B07RVD2T4R/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

Breakout Boards
https://www.amazon.com/gp/product/B07HJ2FYV9/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

I am using a NodeMCU with ESPHome. Config will be below.

Here are some pictures of the setup. This is merely a proof of concept right now. Im planning on 3D printing a nice enclosure for the NodeMCU and attach it to the back and run the flat cable through and to the underside of the lid, with a nice 3D printed enclosure for the sensor as well.

Here is the ESPHome config that i used for the NodeMCU (There is some extra stuff in there as well that i like to add to all my ESPHome nodes that makes version tracking and such much easier);

esphome:
  name: humidor_hygrometer
  platform: ESP8266
  board: nodemcuv2

wifi:
  ssid: "***"
  password: "***"

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "***"
    password: "***"

captive_portal:

# Enable logging
logger:

# Enable Home Assistant API
api:

ota:

switch:
   - platform: restart
     name: Humidor BME Sensor Restart

# Text sensors with general information.
text_sensor:
  # Expose ESPHome version as sensor.
  - platform: version
    name: Humidor BME Sensor ESPHome Version
  # Expose WiFi information as sensors.
  - platform: wifi_info
    ip_address:
      name: Humidor BME Sensor IP
    ssid:
      name: Humidor BME Sensor SSID
    bssid:
      name: Humidor BME Sensor BSSID

#Connect SDA to D2 and SCL to D1
i2c:
   - id: bus_a
     sda: D2
     scl: D1
     scan: True
sensor:
- platform: bme280
  temperature:
      name: "Humidor Temperature"
      oversampling: 16x
      accuracy_decimals: 0
  pressure:
      name: "BME280 Pressure"
      oversampling: NONE
  humidity:
      name: "Humidor Humidity"
      accuracy_decimals: 0
  i2c_id: bus_a
  address: 0x76
  update_interval: 60s
  
# Sensors with general information.
  # Uptime sensor.
- platform: uptime
  name: Humidor BME Sensor Uptime

  # WiFi Signal sensor.
- platform: wifi_signal
  name: Humidor BME Sensor WiFi Signal
  update_interval: 60s

Here is a simple automation that sends push notifications to my phone if the temp or RH go to high or too low. Note that this uses “Options” so if you are running an older version of HA, it will not work. Make sure your version supports Options. Most likely going to add a time limitation to the automation if it gets annoying. Something along the lines of “if RH or temp out of range for more than 1 hour”.

alias: Humidor Notifications
description: ''
trigger:
  - type: value
    platform: device
    device_id: 5b7e0626175f50ef697018d6d83ad12f
    entity_id: sensor.humidor_temperature
    domain: sensor
    above: 72
    for:
      hours: 0
      minutes: 0
      seconds: 0
  - type: value
    platform: device
    device_id: 5b7e0626175f50ef697018d6d83ad12f
    entity_id: sensor.humidor_temperature
    domain: sensor
    below: 65
    for:
      hours: 0
      minutes: 0
      seconds: 0
  - type: value
    platform: device
    device_id: 5b7e0626175f50ef697018d6d83ad12f
    entity_id: sensor.humidor_humidity
    domain: sensor
    above: 72
    for:
      hours: 0
      minutes: 0
      seconds: 0
  - type: value
    platform: device
    device_id: 5b7e0626175f50ef697018d6d83ad12f
    entity_id: sensor.humidor_humidity
    domain: sensor
    below: 65
    for:
      hours: 0
      minutes: 0
      seconds: 0
condition: []
action:
  - choose:
      - conditions:
          - type: is_value
            condition: device
            device_id: 5b7e0626175f50ef697018d6d83ad12f
            entity_id: sensor.humidor_temperature
            domain: sensor
            above: 72
            below: 0
        sequence:
          - service: notify.mobile_app_sm_g975u
            data:
              title: Humidor Temp Alert
              message: Humidor Temperature is Above 72°F
      - conditions:
          - type: is_value
            condition: device
            device_id: 5b7e0626175f50ef697018d6d83ad12f
            entity_id: sensor.humidor_temperature
            domain: sensor
            below: 65
        sequence:
          - service: notify.mobile_app_sm_g975u
            data:
              title: Humidor Temp Alert
              message: Humidor Temperature is below 65°F
      - conditions:
          - type: is_value
            condition: device
            device_id: 5b7e0626175f50ef697018d6d83ad12f
            entity_id: sensor.humidor_humidity
            domain: sensor
            above: 72
        sequence:
          - service: notify.mobile_app_sm_g975u
            data:
              title: Humidor Humidity Alert
              message: Humidor Temperature is above 72% RH
      - conditions:
          - type: is_value
            condition: device
            device_id: 5b7e0626175f50ef697018d6d83ad12f
            entity_id: sensor.humidor_humidity
            domain: sensor
            below: 65
        sequence:
          - service: notify.mobile_app_sm_g975u
            data:
              title: Humidor Humidity Alert
              message: Humidor Temperature is below 65% RH
    default: []
mode: single

Overall, I am very happy so far with how this is working. I look forward to getting a 3D printed enclosure done and put the finishing touches on this. Here are a couple screenshots from HA of the final results so far.

I just noticed theres a typo in my notification. :slight_smile: Should read “Humidor Humidity is below 65% RH”

Nice! And glad I could help!

I’m going to do something similar eventually.