DIY Smart Blinds for Smart home

I’ve been looking for this project since i’ve bought my own flat and saw Home-assistant power.

The idea that your blinds would close with the sun down and then would open in the morning seemed to me like some futuristic thing.

One of the thing that stopped me from implementation was price and size of the block.

What got me started was this article about 28BYJ-48 turbocharging. I got all excited (since I have some of that around) and the breadboard prototype was working*. (Only if motors received voltage from 9 volts, ideally 12v)

Also check out the explanation about driver, motor.

Update from 2020: Finally I made it work ! See updated code and 3d models section.

Price for components:

Count	Component	Price $	Link
1	ESP8266	1.39	https://www.aliexpress.com/item/32633529267.html
1	28byj-48 motor	1.50	https://www.aliexpress.com/item/32896006818.html
100	1K 0603 resistors	0.75	https://www.aliexpress.com/item/32847135098.html
50	ceramic capacitor	2.20	https://www.aliexpress.com/item/32943454441.html
10	esp12f adapter board	1.23	https://www.aliexpress.com/item/32721385289.html
10	9v connector	0.59	https://www.aliexpress.com/item/32876984714.html
50	3.3v voltage regulator	1.01	https://www.aliexpress.com/item/32910803907.html
50	5v voltage regulator	1.42	https://www.aliexpress.com/item/32821350559.html
10	motor connector	1.50	https://www.aliexpress.com/item/32911598577.html
1	witty cloud	2.37	https://www.aliexpress.com/item/32849208288.html
20	16 pin sockets	1.09	https://www.aliexpress.com/item/32799785542.html
10	40 pin female header	1.09	https://www.aliexpress.com/item/32867179300.html
	Total for 1 device	16.14	and lots of parts left …
	Total for 10 devices	42.15	that’s $4 per one!

• Note that power supply is not here in the list since i have not decided how to use it. Also note that a lot of components are left after any assembly.

	Top	Bottom
PCB View

Software part

From the very start I decided that writing own code in this case is a bad idea.

OTA, MQTT, sleep, wifi serial logging, and other things would take plenty time to implemnet and I have already seen Tasmota and EspHomeYaml projects.

My precise combination was not available - with L293D driver and 28BYJ-48 motor, the closest I’ve found was uln2003 stepper. It does show good torque.

Here is a code that made it possible:

# IN1 = 16
# IN2 = 12
# IN3 = 15
# IN4 = 01


stepper:
  - platform: uln2003
    id: my_stepper
    pin_a: 12
    pin_b: 16
    pin_c: 01
    pin_d: 15
    max_speed: 250 steps/s

    # Optional:
    acceleration: inf
    deceleration: inf
    sleep_when_done: true
    step_mode: WAVE_DRIVE

switch:
  - platform: gpio
    pin: 02
    id: red_pin

  - platform: template
    name: "Toggle_Position_Up"
    turn_on_action:
      - stepper.report_position:
          id: my_stepper
          position: 0
      - stepper.set_target:
          id: my_stepper
          target: -200

  - platform: template
    name: "Toggle_Position_Down"
    turn_on_action:
      - stepper.report_position:
          id: my_stepper
          position: 0
      - stepper.set_target:
          id: my_stepper
          target: 200    

Issues / Warnings

• I’ve seen some corrupted / fake L293D drivers. Symphtoms - when toggling positions up or down - it always goes in one direction and has no torque at all.
• Bad motors - same as previous, but direction remains same all the time.

3D Printed models

• Housing: https://www.thingiverse.com/thing:1371349
• Husing 90”: https://www.thingiverse.com/thing:3593641
• Even better housing: https://www.thingiverse.com/thing:3923529
• Chain connector: https://www.thingiverse.com/thing:1174117
• Cog (gear): https://www.thingiverse.com/thing:3586583