Smart Energy Saver

We created the Smart Energy Saver, a device designed to monitor and optimize energy usage within campus buildings at Colby College so that less energy is wasted on campus. By tracking energy consumption, light levels, room occupancy, and temperature, the Smart Energy Saver will notify users to take actions like turning off lights when the energy usage in a room is above normal levels. The solution provides real-time feedback through visual cues and auditory signals. This promotes energy-efficient behaviors and reduces wasteful consumption.

Project materials

1. Adafruit Metro Mini
2. 1 temperature sensor
3. 1 photocell
4. 1 piezo speaker
5. 1 neopixel ring
6. 1 PIR sensor
7. 1 perfboard

Other materials

1. USB-C to micro-USB or USB-A to micro-USB
2. Breadboard
3. Soldering iron and stand
4. PCB holder
5. Fan (optional)
6. Cardboard
7. Batteries
8. 
   

Software Requirements

1. Arduino IDE 2.3.3 or higher

Here, we have the circuit for the smart energy saver as shown above. We'll be using pins A0, A1, and A2 as input and 3 and 6 as output. While we are using these pins for this tutorial, feel free to use different pins as needed. Just make sure that the input pins are analog and the output pins are PWM. Also, make sure to test that the component is working correctly after each step by using the Arduino code below.

1. To wire this circuit on a breadboard, we should first connect our microcontroller to the breadboard's ground and power bus.
2. We are starting with our thermistor. It has three pins, so we can easily connect it to the Metro Mini's analog inputs. We will be connecting it to A0.
3. Next, we will wire our photocell, which will connect to A1.
4. As our last input, we will wire our PIR sensor to A2. Note that we used an IR LED as a stand-in (wiring should be the same).
5. We will wire our speaker, which will connect to pin 3.
6. Lastly, we can wire our neopixel ring to pin 6.

You should get sensor readings similar to the image above. You should also see the neopixel ring light up and the speaker produce a tone. If all of the components are working, great! You can move on to creating the prototype.

For the prototype, you will need a perfboard and some wires, as well as a soldering iron and PCB holder. Again, test that the component is working correctly after each step by using the code provided in the previous step.

1. Start by soldering the microcontroller on the perfboard. Depending on your microcontroller's size, you may need a larger board.
2. First, connect and solder the PIR power pin to the microcontroller's 5V. Connect the PIR ground pin to GND. Lastly, connect the data input pin to A1.
3. Solder the header for the photocell. This step may be confusing, but we are essentially connecting a 10k ohm resistor to ground and one of the photocell legs, and then 5V to the other leg, making a complete loop. Connect and solder the wires as shown in the image above, making sure it is connected to A2.
4. Solder the header for the thermistor. Connect the pin close to the edge to GND. Connect the middle pin to A3 (previously A0). Lastly, connect the pin close to the microcontroller to 5V. Finally, solder the wiring to the microcontroller pins on the bottom.
5. Moving on to outputs, install and solder the header for the neopixel ring. Connect and solder the the header pins as shown above. GND should go to the 2nd GND on the microcontroller, power should connect to 5V, and the data pin should connect to pin 6.
6. For the last component, solder the piezo speaker to the board as shown above. One wire should connect to pin 3 and the other should connect to GND.

You should get readings similar to the ones in the previous step. If not, something may not be wired/soldered correctly. Double check the connections and unsolder if necessary.

Now it is time to assemble the shell. For the top and bottom, cut out 20" x 11" pieces of cardboard. For the front and back, cut out 20" x 20" pieces. For the sides, cut out 20" x 11" pieces. This part is optional, but you can solder a DC power jack onto the board for battery power instead. After doing so, assemble the shell and attach the NeoPixel ring to the front, making sure to cut out a circular hole first. Add a rod/stick inside to stick out of a hole at the top as well. This will allow for motion detecting. For the thermistor and photocell, cut out a rectangular portion for them to be placed outside. If you have a battery pack, connect that to your board and ensure that the system is working. It should still pick up light, temperature, and motion readings.

The final code for the project will be attached here as well.

This system works by activating different LED colors on a neopixel ring.

1. If the red LED is on, that means the room is too bright. The user is recommended to turn off the light if it is not needed.
2. If the blue LED is on, that means the room is too warm. The user should turn off the heater.
3. If the green LED is on, then the motion sensor is likely detecting that no one is in the room. In that case, the user should turn off both the lights and the heater.
4. If system is providing an alert via sound, that means the user should turn off both the lights and the heater.

Lastly, check indicators when entering and leaving rooms and respond to alerts as soon as possible. By following this guide, saving energy can be quite simple and effective, helping you reduce costs while minimizing your environmental impact.

Now that we have a working prototype, here are some potential improvements to the system that you can do:

1. Adding a motor to have the PIR sensor detect motion in 360 degrees
2. Building an interface to set sensor thresholds (via bluetooth or web)
3. Adding another motion sensor near a doorway (separate from the device) that connects via bluetooth to alert if someone is leaving the room but lights/heater is still on.

With these enhancements, you can take your project to the next level, making it more versatile, user-friendly, and energy-efficient. Whether you're a beginner or an experienced maker, this project offers endless opportunities for customization. Happy building!