External Automatic Temperature Adjuster for Thermostats

Anyone in your household that's sensitive to the change in temperature throughout the day? With this project, you can automatically control your thermostat on a time based system, so the members of your household will stop complaining about the weather's effect on indoor temperatures.

Supplies you might need include:

• Particle Argon
• Bunch of wires
• Mini USB to USB cable
• Portable battery
• 28BYJ-48 Stepper motor or stepper motor of preference
• ULN2003 Stepper motor driver
• Rubber wheel for stepper
• Cardboard
• Hot glue gun and glue
• Command strips and or lots of masking tape

Mount your wheel to the stepper motor. Make sure you have a wheel that fits. In this case, mine did not, and I had to surround the motors pin with tape to thicken it, so that it would fit on the wheel's larger diameter hole.

Begin by placing the wires on your stepper motor into the ULN2003 driver. Then, you must accordingly take four wires and connect them from the slots in the driver to your argon. I have my four wires from Int 1, Int 2, Int 3, and Int 4 wired accordingly to the pinholes of D2, D3, D4, and D5 in the breadboard to the Argon. If you are confused, a video is attached showing colored wiring. Then, I took two wires, and wired the negative pin in the driver to ground, and the positive pin to VUSB in the Argon.

Attached is an example of the code that I used for my stepper motor. My goal with this code was to make the stepper motor decrease the temperature at about 8:00 AM, and bring it back up at around 5:00 PM.

The mechanism involves using friction by spinning the rubber wheel against the thermostat, which means that if the wheel were to turn clockwise, the thermostat would move counter clockwise and thus move the temperature down. Then, if the wheel were to move counter clockwise, the thermostat would move clockwise and turn the temperature up. found that moving the motor by plus or minus 400 generally moved the thermostat three degrees. Your experiments may vary, and these values should be changed according to your own thermostat.

In my setup, I set the timezone to where I live in relation to UTC. You should research this on your own to determine what you should set it to. Where I live, I am 5 hours behind UTC.

In my loop, I used some of the time functions found in the particle documentation. These would allow you to set the hour and minute of the day that you want the motor to move. These will vary, but I set it according to my needs. Also, if you would prefer to move the motor less or more throughout the day, you may continue to add more start hour and start minute variables, and If statements in order to achieve this.

Because I did not want my code to execute for the entire minute that I designated, I created multiple delays that would last the entire minute after the motor moves, so that It would only move once. My class was then instructed that this could cause problems with the Particle Cloud System, but after extensive testing, I concluded that this method was not only the most efficient, but worked without error. Use your own discretion.

I have left multiple guiding comments on this code. You should again adjust any values to your preference and needs, such as the set times to move the motor and the steps the motor takes.

Plug in your Argon to your computer with an internet connection, and flash the code. This way, the device will remember it for later, when you plug it into the battery. Ensure that your Argon is in a place where it can get a stable internet connection.

Cut out a cardboard rectangle that will fit your portable battery in a snug manner. Then, create walls on the bottom and side of your choosing, Make sure to make the wall with the USB port side smaller, so that you can still plug in your cable to power your argon, as I have done here. Make sure you know where you are going to put the holder in relation to the contraption, and plan accordingly. For example, I put the USB port side on the left of the holder, as I mounted the battery on the right of the thermostat. To put the walls together, you can use a hot glue gun and copious amounts of glue. I used a lot, and remembered to apply it to the inside as my battery was quite heavy. Use proper caution with this equipment. Optionally, you can reinforce this structure with some duct tape.

Similarly to the battery holder, trace cardboard in the shape and size of your Argon's back. Then, make small walls for the sides and in the front. To avoid future problems, make sure that you make a smaller cardboard "fence" in an L shape on the side so that the Argon doesn't slide out. Remember not to make walls that will obstruct the wiring of the device, so make them small. I still used a hot glue gun to construct it. Remember to plan accordingly for where you are placing your Argon in relation to the contraption and thermostat, just like the battery holder. You may also reinforce this structure with duct tape if you want to, however it is not necessary.

In this step, you want to position your motor in any way where the wheel can make tight friction with the thermostat as it moves, in order to turn the thermostat with it. If you can mount your motor directly to the wall in a way where the wheel is making proper contact with the thermometer, skip this step and instead use command strips and or tape to mount the motor directly to the wall.

For the final cardboard structure, you can construct a stepper motor mount. with cardboard. Because my motor and wheel are too offset from the wall to make contact with the thermostat when directly wall mounted, I had to create a cardboard mounting device that angled my motor inwards so that the wheel could touch the thermostat. Again, I just created a triangular prism mounted to a cardboard rectangle. Then, I placed my motor on the sloping face of the mount so that it would point the wheel inwards to make contact with the thermostat.

Begin by making rough estimations and measurements of where each item/mount should go in relation to the thermostat, so that each wire can remain plugged in and within reach of each device.

I placed my battery mount on the right side of my thermostat, my stepper motor mount directly beneath the thermostat, and my Argon mount directly underneath the stepper motor mount.

To secure the mounts to the wall, I used copious amounts of command strips and masking tape. Remember to use a tape that will not remove any paint from your wall, as the goal of this project is to ensure that no parts of your house are damaged or remain permanently altered. I used command strips that can easily take multiple pounds of force, and that go directly from your wall to whatever you are mounting. Tape reinforcement is optional and will likely not look as good as with just command strips, but will be stronger. I do not recommend using only tape, and no command strips, as they hold most of the weight.

Put each item into their respective mounts, unplugged. Then, rewire everything. Place your charged portable battery in the mount, and plug in your argon via the mini USB to USB cable, to supply it with power. Turn on your device. If you did it right, the Argon should already have the code saved from when you flashed it to the device before, and will not need to be plugged into your computer with your saved code.

Your Argon should now be able to automatically move your thermostat depending on your set time of day, using the rubber wheel! The mounts also allow your devices to be removed. If you need to charge your portable battery, you can simply unplug the Argon, take the battery out of the mount, and charge it. If you need to use the argon, you can simply remove the wires and take it out of its mount. This project seems simple, but is hard to get right. Following these steps will be crucial to your success!