I built a very loud alarm siren for my home automation system. Construction information is on Hackster.io with parts, code, etc.
My new project is a Internet of Things kitchen counter LED light strip. The goal was to implement a 21st century light switch using bright and energy efficient LED lights. This required the replacement the mechanical switch with a hand-motion proximity sensor for on and off. Other features include:
The ESP-01 presents a couple of problems, because it only has two GPIO ports. I needed to use the I2C bus to communicate with the OLED, which used both GPIO. So I decided to use an MCP23008 IC to handle interrupts (INPUT) and to control the MOSFET (OUTPUT). This enabled me to use I2C bus and added 8 more GPIO ports.
I used two two proximity devices on this project. The first is the PIR motion sensor. I really like the Parallax, Inc. PIR Sensor – Rev B, because it can operate on 3.3 volts and has a red LED to indicate detection of motion. The second proximity sensor is the Adafruit, VCNL4010 Proximity/Light sensor. It measures both near proximity and ambient light. The VCNL4010 uses the I2C bus to communicate data and it has a configurable interrupt signal. I used the MCP23008 to handle both interrupts – PIR and VNCL4010.
I added a cool on/off switch from Adafruit as the final touch. The Rugged Metal On/Off Switch with Blue LED Ring – 16mm Blue On/Off looks great.
The software features included: (a) NTP time set, (b) AP mode when the ESP-01 could not connect to its predefined SSID/password, (c) defaults in EEPROM, (d) my version of the VNCL4010 library, (e) my MCP23008 library with interrupt handling, and (f) RESTful interface for the website configuration stuff.
The next step was to fit everything in a small wooden box that I would mount on the wall.
I had a lot of trouble with the VNCL4010 when it was installed in the box. I need to spend time determining how much of the PCB board needs to be exposed from a hole or mount in the box. My first attempt blinked on and off after a couple of minutes.
Below is a short video of the light working. I’m planning to move everything to an Adafruit proto-board and finding a smaller box.
Next steps in a couple of weeks.
I wanted to add video surveillance to my home automation project, which was a good excuse to add another Raspberry Pi to the project. I’d tried using an ATMega328 with the Pi but found it too cumbersome to write Python code and Arduino ATMega code. It worked with an I2C interface but I wanted something simpler.
The diagram below illustrates the Adafruit photo-board with all of the necessary interfaces to 5 volt and 3.3 volt devices.
Features of a Raspberry Pi 2 Surveillance project:
I enclosed the project in a plain wooden box. As you can see the cable management was a hassle with the hinge and external interfaces on the door.
All of the code is in Python. There are four main packages
I will publish the code to GitHub when I get a chance.
Another recent project is a cat entertainment center using a combination of servo controlled mice and feathers. For the prototype I used a wooden wine case (6 pack) and inserted 1-1/2 inch tubes and servos for two mice. A slot on the side uses another servo to pop out a feather. It has been very popular with Nebbie, our six month old kitty.
Features include the following:
One of the challenges was to make it robust enough to handle abuse from the kitty while at the same time “NOT HURTING” my kitty. Nebbie has pulled out the servos several times. She also runs over to the box as soon as she hears the servos power up.