Introduction
My current apartment’s blinds have a ball chain to raise and lower them. There’s a gear at the top that the chain turns which in turn turns the rod on which the blinds roll. If I put another gear at the bottom and turn that with a motor, that would open and close the blinds.
Motivation
I like to sleep in total darkness but since I have to wake up early, it is nice to have the blinds open so sunlight can get in in the morning and help wake me up. Until now I have been leaving the blinds open all night which lets light in. Having motorized blinds would allow me to leave the blinds closed all night and have them open automatically in the morning. Additionally, I open the rest of my blinds in the morning and I close them when it gets dark, I plan on automating this so I don’t have to do it manually.
Implementation
The plan is to use a Raspberry Pi to act as a hub where I will install Homebridge so I can control it using the Home app on my iPhone. The individual blinds will be controlled using an Arduino which the Raspberry Pi will communicate with using Wi-Fi. The Arduino controls a stepper motor through a motor controller. The motor will in turn move the ball chain using a 3D printed ball chain gear.
Materials
Here is a list of all the parts that I plan on using in this project:
- Raspberry Pi 3
- Adafruit Raspberry Pi B+ / Pi 2 / Pi 3 Case – Smoke Base – w/ Clear Top
- 5V 2.4A Switching Power Supply with 20AWG MicroUSB Cable
- 8GB MicroSD Card with NOOBS 2.0
- Arduino UNO WiFi
- Arduino Motor Shield
- Stepper motor – NEMA-17 size – 200 steps/rev, 12V 350mA
- 12 VDC 1000mA regulated switching power adapter – UL listed
- 2-Way 2.1mm DC Barrel Jack Splitter Squid
- Female DC Power adapter – 2.1mm jack to screw terminal block
Current Status
I have all the parts except the Arduino and the motor shield. This is pending the Arduino UNO WiFi to become available on RobotShop.
I installed Homebridge on the Raspberry Pi but I still need to install a plugin that allows me to communicate with the Arduino. I am waiting for the Arduino to arrive so I can test my configurations.
In the meantime, I am designing the ball chain gear. I plan to 3D print this at the Kitchener Public Library.