Smart lock using DC motor with encoder

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3

I haven’t actually printed the model I posted on this thread, but I printed a previous version which was used on a smaller motor. This was not powerful enough to turn the key, only 5.6kg/cm.

The print was really good and stable, but a friend of mine helped me make a wooden one so instead of printing the one I posted, I used the wooden one.

This is how everything is connected:

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IMG_20210108_2314353083×2119 399 KB

This video shows how it works with Home assistant, though I am currently using a lock template to unlock and lock.

And this is the actual project:

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4

This new version checks works with doors that use latch. It opens the door with the latch and after 5 seconds it gets restored. I am using an external device connected with a magnetic sensor which checks when the door closes. In that case it locks all the way.

esphome:
  name: smartlock
  platform: ESP32
  board: nodemcu-32s

wifi:
  ssid: mywifi
  password: mypassword

# Enable logging
logger:

# Enable OTA updates
ota:

# Enable Home Assistant API
api:

globals:
  - id: is_locked
    type: bool
    restore_value: yes
    initial_value: 'true'

binary_sensor:
  - platform: template
    name: "Is locked"
    lambda: "return id(is_locked);"
  - platform: gpio
    id: button_inside
    pin:
      number: GPIO23
      mode: INPUT_PULLUP
      inverted: True
    on_click:
      then:
        - switch.turn_on: unlock

switch:
- platform: gpio
  pin: GPIO26
  interlock: &interlock [unlock, lock]
  name: Unlock
  id: unlock
  on_turn_off:
  - globals.set:
      id: is_locked
      value: 'false'
- platform: gpio
  pin: GPIO27
  interlock: *interlock
  name: Lock
  id: lock
  on_turn_on:
  - script.execute: lock_until_time
  on_turn_off:
  - globals.set:
      id: is_locked
      value: 'true'

sensor:
  - platform: rotary_encoder
    id: motor_encoder
    pin_a: GPIO15
    pin_b: GPIO13
    on_value:
      then:
        - script.execute: stop_at_the_end

script:
  - id: lock_until_time
    mode: restart
    then:
      - delay: 3s
      - switch.turn_off: lock
  - id: stop_at_the_end
    mode: restart
    then:
      - delay: 200ms
      - if:
          condition:
            switch.is_on: unlock
          then:
            - script.execute: open_latch
      - switch.turn_off: lock
      - switch.turn_off: unlock
  - id: open_latch
    mode: restart
    then:
      - delay: 5s
      - switch.turn_on: lock
      - delay: 500ms
      - switch.turn_off: lock
5

Hola me ha encantado tu proyecto y es justo lo que estaba buscando creo que solo tengo una duda que voltaje tiene que ser el motor ya que me estoy haciendo una lista de los componentes para comprarlos.

Muchas gracias

7

hi, I don’t understand Spanish, but with google translate I got it.
The voltage of the motor and the RPM don’t matter, as long as it has the necessary torque to turn the key.
The more RPM you have, the faster the lock will be and lower the RPM.

8

Perdona no se hablar bien ingles

mi duda es sobre como alimento el motor ya que el esp32 creo que funciona con 5v?
si me puedes ayudar ya que tengo la impresora 3d y me gustaria mucho poder hacerlo gracias y perdona no poder hablar en ingles :pray: :sweat:

el L9110S es alimentado por el esp32? me podria decir cual es su motor y comprare el mismo ?gracias

9

I don’t think that you can find a motor with 5v that is powerful enough to turn the key. If you see the diagram, the red and purple wires are 9v-24v based on the requirements of your motor. The motor is powered through the L9110S driver which is controlled by ESP32.

1 Like
10

me podria decir cual es su motor y comprare el mismo? gracias

11

I bought this one:

13

I bought the 24V 60RPM, but anything with more than 8kg.cm will be fine.

14

If you are interested on another take on a Smart Lock, check out this new thread that I wrote:

15

Very very good project!!!
Where find I the firmware to upload on esp32s?

16

You need to install ESPHome and configure it using the YAML i’ve posted.

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17

Thanks a lot for your answer…
From your 3d project I don’t understand where you positioning the esp32s etc ect components. Is it possible to attach a real photo to understant the components location?

18

There is no place on the 3D print for the components because I don’t have it near the lock.
I’ve extended the cables around the door and I have them installed on a box on the wall.
I no longer use this lock so I can’t show you pictures. I am using another type of lock: Smart Lock with Gears

19

@bkbilly how does esp home check if the key cant turn further? Its not clear to me from the yaml code… building my own smart lock right now and found your post… thank you!

20

I haven’t implemented a stop action on my YAML.
I believe with the help of the rotary encoder, this could be possible.

21

Oh ok, so this feature is not included (as you have written) that it stops when the key cannot turn any further? Or do I get it wrong somehow? I try to archive the same at the moment…

22

I couldn’t remember exactly how it works because it’s almost 3 years that I last used this.
By investigating the configuration further, I figured it out.

The rotary_encoder triggers the script stop_at_the_end, but it waits for 200ms.
This is done on any change on the encoder value which restarts the script, so it won’t continue with turning of the rotation of the motor.
Once the encoder stops getting new values, the script will have the time (200 milliseconds) to continue and stop the movement of the motor.

Hope this makes this clear.

23

ah thank you so much, quite clever!

missed somehow the rotary_encoder, thanks so much for explaining! does your lock still work nice?

Or were there any further problems then if I may ask?

24

I don’t use this anymore because it is quite bulky and doesn’t look so nice, but mostly because the motor is using a lot of gears to have more torque which makes it impossible to turn the key from the other side.

I replaced it with this which is using a stepper motor with 3D printed gears and I’ve been using it for about 3 years and it works perfectly.

Either smart lock you use should run without issues for years, but you need to have a good power supply.

1 Like