Craft Details

Skills Needed:

Categories:

Smart Coffee Grinder

Modification of standard on/off button coffee grinder (Graef CM820) for time controlled grinding for one or two cups or weight controlled grinding.

The second relay in the pictures is not necessary, it can be used to control the coffee maker next to the grinder.

A smaller Microcontroller (without wifi, less pins) can do the job, but I had an ESP32 around and use it for other home automation purposes such as kitchen temprature, humidity and CO2 level or muting sonos, communication with home assistant etc.

There are many other nice projects like this, but the implementation with ESPhome was easier than copying and modifiying one of these projects (less than 200 lines of code, see below).

e.g.

I designed the housing and printed it on my RatRig V-core 3.1

Part	Details	Cost €	Supplier	Code module	3D model
ESP32	-WROOM-32D / AZ Delivery Dev Kit C V4	4,10	Aliexpress / Amazon	ESPhome	Grabcad
LC Display Tinsharp	TC1602B-01 with lcd_pcf8574 (16×2 Characters)	1,50	Aliexpress / Amazon	ESPhome	Grabcad
Relay	KY-019 (5VDC / 230VAC 10A)	0,50	Aliexpress / Amazon	ESPhome	Grabcad
Rotary Encoder	KY-040	0,50	Aliexpress / Amazon	ESPhome	Grabcad
Power Supply S-10-5	S-10-5 (230VAC -> 5VDC 10W 2A)	5,00	Aliexpress / Amazon	–	Grabcad
Housing 3D-printed	PLA Polymaker Polyterra charcoal black, 280g	5,00	3d print	–	Thingiverse
	Sum	11,60

for weight control mode:

Part	Details	Cost €	Supplier	Code module	3D model
Load cell amplifier	HX711	1,00	Aliexpress / Amazon	ESPhome	Grabcad
Load cell	100g or 500g	1,00	Aliexpress / Amazon		Grabcad

Just for fun (not needed for coffee grinder):

Part	Details	Cost €	Supplier	Code module	3D model
CO2 Sensor	MH-Z19B, C or E	7,00	Aliexpress / Amazon	ESPhome	Grabcad
Humidity and Temperature Sensor	GY-21 with HTU21, SHT21 or AHT21	0,50	Aliexpress / Amazon	ESPhome	Grabcad

Code (Esphome yaml config file)

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esphome:
  name: icoffeegrinder

esp32:
  board: az-delivery-devkit-v4
  framework:
    type: arduino

logger:
  level: DEBUG  
  baud_rate: 0

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password
  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: !secret wifi_hotspot
    password: !secret hotspot_password

captive_portal:

i2c:
  - id: bus_a
    sda: 13
    scl: 16
    scan: true
  
display:
  - platform: lcd_pcf8574
    dimensions: 16x2
    i2c_id: bus_a
    address: 0x27
    id: my_display
    lambda: |-
      id(my_lcd_menu).draw();
      if (!id(my_lcd_menu).is_active())
      it.print("Menu is not active");
      
lcd_menu:
  id: my_lcd_menu
  display_id: my_display
  active: true
  mode: rotary
  on_enter:
    then:
      lambda: 'ESP_LOGI("display_menu", "root enter");'
  on_leave:
    then:
      lambda: 'ESP_LOGI("display_menu", "root leave");'
  items:
    - type: label
      text: 'INGOS KAFFEE'
    - type: command
      text: '1 Cup'
      on_value:
        then:
          - switch.turn_on: relay1
          - delay: !lambda return id(number_1cup).state * 1000;
          - switch.turn_off: relay1
    - type: command
      text: '2 Cups'
      on_value:
        then:
          - switch.turn_on: relay1
          - delay: !lambda return id(number_2cups).state * 1000;
          - switch.turn_off: relay1  
    - type: command
      text: 'Grind' # toggle grinder on/off
      on_value:
        then:
          - switch.toggle: relay1
    - type: menu
      text: 'Settings'
      on_enter:
        then:
          lambda: 'ESP_LOGI("display_menu", "enter: %s", it->get_text().c_str());'
      on_leave:
        then:
          lambda: 'ESP_LOGI("display_menu", "leave: %s", it->get_text().c_str());'
      items:
        - type: number
          text: 'Sec 1 Cup'
          format: '%.2f'
          number: number_1cup
          on_enter:
            then:
              lambda: 'ESP_LOGI("display_menu", "number enter: %s, %s", it->get_text().c_str(), it->get_value_text().c_str());'
          on_leave:
            then:
              lambda: 'ESP_LOGI("display_menu", "number leave: %s, %s", it->get_text().c_str(), it->get_value_text().c_str());'
          on_value:
            then:
             lambda: 'ESP_LOGI("display_menu", "number value: %s, %s", it->get_text().c_str(), it->get_value_text().c_str());'        
        - type: number
          text: 'Sec 2 Cups'
          format: '%.2f'
          number: number_2cups
          on_enter:
            then:
              lambda: 'ESP_LOGI("display_menu", "number enter: %s, %s", it->get_text().c_str(), it->get_value_text().c_str());'
          on_leave:
            then:
              lambda: 'ESP_LOGI("display_menu", "number leave: %s, %s", it->get_text().c_str(), it->get_value_text().c_str());'
          on_value:
            then:
             lambda: 'ESP_LOGI("display_menu", "number value: %s, %s", it->get_text().c_str(), it->get_value_text().c_str());'        
        - type: back
          text: '<<<'

number:
  - platform: template
    id: number_1cup 
    optimistic: true
    min_value: 1.0
    max_value: 60.0
    step: 0.2
    restore_value: true
    on_value:
      then:
        lambda: 'ESP_LOGI("number", "value: %f", x);'
  - platform: template
    id: number_2cups 
    optimistic: true
    min_value: 1.0
    max_value: 60.0
    step: 0.2
    restore_value: true
    on_value:
      then:
        lambda: 'ESP_LOGI("number", "value: %f", x);'

sensor:
  - platform: rotary_encoder
    id: rotaryencoder1
    pin_a: GPIO25
    pin_b: GPIO33
    on_anticlockwise:
      - binary_sensor.template.publish:
          id: backlight
          state: ON
      - binary_sensor.template.publish:
          id: backlight
          state: OFF
      - display_menu.up:
    on_clockwise:
      - binary_sensor.template.publish:
          id: backlight
          state: ON
      - binary_sensor.template.publish:
          id: backlight
          state: OFF
      - display_menu.down:

switch:
  - platform: gpio
    id: relay1
    pin: GPIO19
    restore_mode: ALWAYS_OFF # ensure Relais is alway off on restart

binary_sensor:
  - platform: gpio
     id: rotaryencoderbutton
    pin: 
      number: GPIO32
      inverted: true
    filters:
      - delayed_on: 10ms
      - delayed_off: 10ms # debouncing
    on_press:
      - binary_sensor.template.publish:
          id: backlight
          state: ON
      - binary_sensor.template.publish:
          id: backlight
          state: OFF
      - display_menu.enter:
  - platform: template
    id: backlight
    filters:
      - delayed_off: 20s
    on_press:
      then:
        - lambda: |-
            id(my_display).backlight();
    on_release:
      then:
        - lambda: |-
            id(my_display).no_backlight();

Skills Needed:

Categories:

Smart Coffee Grinder

Code (Esphome yaml config file)

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Smart Coffee Grinder

Skills Needed:

Categories:

Share This Craft

Smart Coffee Grinder

Code (Esphome yaml config file)

Comments

Leave A Comment Cancel reply

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