Hello! So I was busy with a cool DIY project from a few days. I had ordered some components and they are yet to arrive. In the mean time I got a great idea. Almost everyone uses a wall clock to keep their life going smoothly, but have you wondered how would it be to have a digital or analog clock projected on the wall? So in this instructable I will try to accomplish this task with a very simple cardboard wall clock projector!

Since this instructable is in the cardboard contest, please consider voting it if you think it's good. Thank you.

Materials and Tools:

Cardboard box (a shoe box should work fine)

Magnifying glass

Glue, Black Tape, Scissors

A smartphone

Step 1: The Outer Case

The outer case of the projector is going to be made out of cardboard. The cardboard shoe box I used had too much graphic. So I inverted the box in such a way that the graphic side stays inside and the plain cardboard is seen from outside. I did this by cutting along one of the sides of the box, inverting it and sticking the side back with black tape. I used black tape because it doesn't allow leakage of light. It is a good idea to cover all the edges of the box with black tape to avoid leakage of light from any direction.

I then cut out a hole at the front that has a diameter same as that of the magnifying glass. Cutting a hole using a scissor is a bit difficult so I used a paper cutter. Really sorry for the low resolution images. I made this project at night and my smartphone struggles a lot in low-light photography.

Step 2: Fix the Lens

Find a good and clear magnifying glass for the main part of the projector. Mine is from an old pair of binoculars and it had an outer covering, so I could directly pop it into the hole I made for it. I used a little adhesive to make the fixture permanent. It is a good idea to clean the lens before you permanently fix it in.

At this point you may say 'Hey, this is cheating, you're just building an ordinary smartphone projector'. Well you are right. I agree that it is like any other smartphone projector. But trust me, it is a way better use for a smartphone projector than for using it to watch films/videos. The quality of image projected using such projectors aren't good and they are laterally inverted. So forget subtitles (unless you make a bigger one with mirrors angled at 45 degrees which is harder to make). A better option is to copy the movie/video to a pen-drive and watch it on your LED TV or just cast it.

This is a better use of a projector. The idea is not mine though. I had built a similar projector two years ago and someone suggested this way of using it. But it needs some changes before it can be used this way.

As you can see, I pierced a few holes at one side. Just in case I would want to use it as a video projector.

Step 3: The Smartphone Holder

I had this old Samsung GT-S7392 lying in my house. It lags a lot and opening an app in it is a nightmare. Its over 6 years old and crashes a lot. My original idea was to use the smart display clock on my phone that shows the clock when a tiny motion is given to the phone. The idea was to have the projector kept beside the bed on a table and tap it to display the clock on the wall.

Because I found this samsung phone, I'm going to make a permanent projector by directly fixing the phone inside it. I made the phone holder from a rectangular piece of cardboard as on the first image. I then used double sided tape to fix the phone inside. I stuck the phone case to the holder instead of the phone itself, so that I can take the phone out if I want to.

Step 4: Mirror Mirror!

Now here's a problem I noticed. As I mentioned earlier, the projector inverts the image like a mirror. So we will have a clock that displays 4:00 instead of 8:00. A good way to solve this issue is to use mirrors. But I didn't want to make the project complicated. So here's what I did.

After a little research, I found this app called Mirror Clock.This app just laterally inverts the clock face so that it can be seen straight on a mirror. That's exactly what we need! There are options between digital and analog, I prefer the analog one though.

Also, the lens inverts the image upside down. So you will need to turn off auto rotate and keep the phone upside down inside the projector.

Step 5: Project It!

All you need to do is fire up the app, set the phone at maximum brightness and insert the phone into its case (the one we mounted on the holder). It does display the clock pretty well. I didn't have a powerful magnifying glass so the image couldn't go much big before it loses its sharpness. You may need to adjust both the holder inside the case and the whole projector to focus the image at the desired size. Basically you move the projector away from the wall to increase the image size (thereby decrease brightness of the image) and then adjust the phone to get it to focus.

I also made a hole next to the speaker holes through which I can pass my charging cable to charge the phone in case the battery goes down. It can also simultaneously charge and display the clock. Oh yes, don't forget to set the sleep options in the settings to 'never'.

Again sorry for the poor image quality. It was quite hard to get the photo of the projected clock, after quite a lot of editing I could get it properly.

It actually ooks pretty good on the wall. I think I will add a matte black cover on the projector so that it looks sleek and minimal when lying on the table.

I hope you'll enjoy building it. If you've liked the idea, please vote it for the cardboard contest. See you soon!