Introduction: Digital Signage Solution for K-12 Classrooms

I decided to come up with this project because my teacher wanted an easier way to interact with the class, without losing the flexibility he needed. After some brainstorming, I decided to come up with this project.

The best plan was to attach a Raspberry Pi 3 onto the back of a TV. With the built in WiFi, all we needed was a wireless connection, a HDMI connection, and a power outlet. This allowed us to basically attach it seamlessly and allow for a beautiful digital display for classrooms.

Step 1: Purchasing

Before we get started on the making of this device, we are going to need some supplies:

  • Any Television with VESA Mounts (Example)
  • Raspberry Pi 1/2/3 (Example)
  • WiFi Dongle (Unless you have the Raspberry Pi 3) (Example)
  • Television VESA Mount (Example)
  • Raspberry Pi 3 VESA Mounting Case (Unless you have a 3D Printer) (Example)

Step 2: Fitting the Raspberry Pi

Before we do anything, we need to make sure that everything fits properly inside the mount. Whether it is 3D-printed or purchased online, there is always a change the case could be defective. If it is, and we still put everything together, it could risk damage to the devices.

Put your Raspberry Pi into the mount and make sure the screws fit properly. If everything is lined up, you should have no problem inserting the device.

Step 3: (Optional) Cut the Holes in the Mount

To provide proper airflow to the device, it is always recommended to provide some sort of pathway for air to travel. One of the ways you can do that is by drilling holes through the plate that came with your wall mount.

First, Trace your holes onto the plate. Depending on the mount you get, they could be on the side or right below the Raspberry Pi.

Second, create the pilot holes. Since it is solid metal, you are going to need a strong drill to cut through it. Once you get the correct drill bit, part the pilot holes so you do not swerve out of place.

Third, start to drill! Make sure you are going clockwise, or else you will not get any results.

Finally, after the holes are made, start to sand. This makes sure than no damage will happen to anyone that might reach their hand near the micro-computer.

Step 4: Cut Your Screws for the Mount

The screws that come with the mount are usually going to be longer than you need. You want to make it shorter, so there is less stuff poking out of the back, while still providing enough room for the Raspberry Pi inside of the case.

All you need is a hand saw. All you really need to do is cut each screw in half, staying aligned to the thread.

After you cut them, use a grinder to smooth out the edges, so you do not risk damage to consumers who might be poking around the back of the device.

Step 5: Setup the Wall Mount

Now it is time to setup your wall mount. Depending on your location, you are going to need the proper drilling tools. Make sure you are properly equipped for your setup.

First, line up your holes on the wall to match the Wall Mount you purchased. Once you do that, trace out the holes so you know where to drill. Once you finish that, start drilling.

Once the holes are completed, screw in the top hole with the mount connected to it. This will make it easier to square up and align properly.

Screw in the bottom screw(s) and slowly alternate between the two while tightening. This provides an even strain on the device.

Apply any protection that might be included with the wall mount, and/or any other accessories that go along with it.

Step 6: Attaching the Raspberry Pi

Now, all you have to do is connect the Raspberry Pi onto the plate that you originally modified. Since it uses different dimensions compared to a full-sized TV, it should be relatively easy to screw in.

Using four generic screws, screw the mount with the Raspberry Pi into it facing towards the part facing the TV. This will put it in between the Television and the Plate, therefore not putting any pressure onto the case.

VESA Mounts are in a 1:1 ratio, so you can face the Raspberry Pi any way you want. My recommendation would be to place the power port towards the direction of the outlet you are using.

Remember to leave room for the screw spacers we talked about earlier, as these are necessary to properly mount the TV.

Step 7: Attaching the Cables

Depending on your location, you are probably going to have an outlet near you. Personally, we ran our cables up through the ceiling to create a cleaner look.

The full list of cables you will need:

  • HDMI Cable
  • Raspberry Pi Power Cable
  • TV Power Cable
  • Optional Peripheral Connections

You only need two outlets, one for the Raspberry Pi, and one for the Television. Everything else can be connected either directly to the TV, or through wireless.

As you can see in the photos, the only cables that actually leave the devices are the two power cables. The rest run internally into the TV's HDMI cable.

Step 8: Attaching the TV

To connect the TV, you are going to need to do the things you see in the picture.

First, you should screw in the bolts we cut in the earlier steps into the TV.

After you do that, add the spacers that should have come with the Television.

Slowly and carefully, slide the TV onto the plate for the Wall Mount.

Screw on the nuts evenly, until the TV is right on the edge of the Raspberry Pi case.

This will create a secure binding between the plate and the television, while still not putting any weight onto the Raspberry Pi.

Step 9: Setting Up the Raspberry Pi OS

The OS I decided to use was Raspbian OS. It is a Linux-based distribution that was made specifically for the Raspberry Pi. It is well optimized for a mobile digital solution, and is able to access the internet and use basic software.

To install the OS, you are going to need to take the Micro-SD card that came with the Raspberry Pi. Insert it into any Windows computer and make sure it is recognized.

Download Rufus, which is a program designed to load images onto flash devices. You can use this program to install Raspbian OS onto the Micro-SD care.

Download the distribution from the official Raspbian OS website, which can be found here. Once you download that, just load it into Rufus and choose the correct device.

Let it load through, and when it is completed you now have a bootable device! Just re-insert it into the Raspberry Pi on the back of the TV and you are ready to go!

Step 10: Finished Product!

Just turn on your Raspberry Pi and you are ready to go! Now you can load anything from a Google Calendar all the way to a YouTube video. With the flexibility of Linux, and access to the internet, you can use this affordable device for a variety of different things.

Thanks for reading, and I hope you enjoy!