INTRO

I originally bought this projector for another project that required it to run 24 hours a day.

Unfortunately, the inexpensive projector failed much sooner than expected, forcing me to stop that project. Buying an expensive replacement wasn't an option, and I didn't want to create more electronic waste.

Before throwing it away, I opened it up and discovered that many of the components were still working. The main problem was the original control board.

So instead of throwing the whole projector away, I decided to build my own control system and reuse the parts that still worked.

I reused the original optical system and combined it with a Raspberry Pi 3, ILI9341 TFT display, camera, and computer vision.

The result is AI HoloProject X1 — an interactive projection system that turns an ordinary floor into a digital interface.

I didn't replace the projector. I replaced what was broken.

Project Goal

The goal was not simply to repair an old projector.

I wanted to give the hardware a completely new purpose: turning a normal floor into an interactive digital interface using projection and computer vision.

This project started with a broken projector.

It had originally been used for another project that required continuous operation, but the projector eventually failed.

Although the projector could no longer function normally, I wanted to find out whether its internal components could still be useful.

I opened the projector and inspected the internal components.

The main control board was no longer working, but several important components were still usable.

The optical system, projection lens, mechanical parts, cooling system, and other components could potentially be reused.

I carefully removed the optical components from the original projector.

The goal was to preserve as much of the original optical hardware as possible instead of replacing everything with new components.

The useful parts included the projection lens and optical elements used to guide and focus the image.

Since the original control board was no longer working, I decided to build my own control system.

This allowed me to reuse the working optical and mechanical components without having to purchase another complete projector.

The new system would provide the control and processing needed for the new application.

I integrated an ILI9341 TFT display into the modified optical system.

The display provides the graphical content that is processed through the optical system and projected onto the floor.

This allowed me to create a completely new image source while continuing to reuse the original projector optics.

A Raspberry Pi 3 is used as the main computer for the project.

It handles the graphical interface, camera input, interaction processing, and communication between the different parts of the system.

A projector can display an image, but it cannot understand what a user is doing.

To make the system interactive, I added a camera.

The camera observes the projected area and provides the input needed for computer vision and interaction detection.

A GUI Designed for the Floor

The next step was creating a simple graphical interface designed specifically for projection onto the floor.

Large, clearly separated buttons make the interface easier to see and easier for the camera to detect.

Example interface:

1. Video
2. Calendar

This circuit connects the ILI9341 TFT display to the Raspberry Pi 3 Model B while preserving the original pin configuration used in the project.

The ILI9341 provides the visual output, while the Raspberry Pi 3 handles the display control and processing. The circuit uses the required SPI communication lines, together with the control signals for the display.

The Raspberry Pi Camera is connected separately through the Pi 3's CSI camera interface. It is used as the visual input for the computer-vision interaction system.

The wiring shown in this diagram follows the actual circuit used in AI HoloProject X1.

Key connections:

1. ILI9341 → Raspberry Pi 3
2. MOSI (D10)
3. SCK (D9)
4. CE0 (D8)
5. D24
6. D25
7. Power and Ground
8. Raspberry Pi Camera → CSI interface