James Wahawisan

Automated blind control via an Amazon Echo Dot and Raspberry Pi

12/25/16

Videos

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Build Summary

My apartment has large windows that are great during the day, but get a lot of light pollution at night. I’ve been wanting to automate the blinds given the advent of Siri and Alexa, but have hesitated assuming I would need to machine or fabricate something. That was until I discovered Amazon literally sells every coupler imagineable.

I ended up automating through Alexa as it is already so well supported. I was up and running in under an hour by simply combining fauxmo with Adafruit’s motor drivers. See my poorly written code here.

BOM:

• Amazon Echo Dot
• Raspberry Pi with accessories
• Adafruit Stepper Hat
• Nema 17 Stepper Motor .4A 12V
• 12V 1.5A Power Supply
• 5mm to 8mm Coupler
• Mounting Bracket
• 6” Bar Clamps

Pictures

Build Details

Automatic Reconnection to WiFi

I noticed after a few days of use that the Raspberry Pi would disconnect from my AP and remain offline. This guide appears to have fixed my woes. As an Ubuntu user I’ve already wasted too much time trying to understand WiFi and Linux issues.

Motor Speed

The motors run a bit slow, but anything beyond 1/4 microstepping was unbearably loud. By default the Adafruit library runs 1/8 microstepping.

Automatic startup

The script runs automatically on startup after following this guide. I had to add in a sleep delay as it was running before acquiring wifi.

Future Work

• File-based state to be robust to power cycling
• Non-binary adjustment? (physical input)
• Position sensors? (encoders)