Universal infrared remote control

Project Overview
Our project is a universal infrared remote that can record, store, and rebroadcast any infrared signal.
Everyone is familiar with the classic coffee table chaos of half a dozen TV remotes that each accomplish a very specific and unique function, but no one knows which one does what. Our project is the solution to that problem. We have designed an infrared remote that can store up to ten remotes with eight buttons per remote, and the remote can be programmed with any infrared communication protocol. To program the remote, you simply turn it on and plug the USB cable into your computer and activate the serial interface. The interface will prompt you to name the remote and button that you want to add, and then you will be prompted to record your remote’s infrared signal by pointing your remote at the front of our Universal Infrared Remote and pressing the desired button. Once you have recorded the remotes and buttons that you want, you can unplug the USB cable from your computer. All the devices and remotes will be saved locally on the SD card, so your data will persist through power cycles. If you want to delete any remotes or buttons, you may due so through the serial interface.
We have often found that class projects are discarded after the completion of the course, but we wanted something that we would be able to use in our everyday lives. The most crucial feature of this remote that allows it to be legitimately useful is the non-volatile memory of the SD card. This allows the user to have the unpowered remote sitting on their coffee table, and when they power it on, all of their buttons and remotes are still there, ready to be used. Our project was a resounding success despite many hiccups along the way, and we are very proud of our demonstration.
Click through the other pages of this website to read more about our project, its design, and our process.

Detailed Project Description

Universal infrared remote control lets home appliances be switched and monitored from a phone, a web page or by voice, with the actual state fed back to the app so the user always sees whether a load is on or off.

How It Works
1. Relays are wired between the controller and the appliances (lights, fan, socket).
2. The controller connects to Wi-Fi and to the chosen cloud/app service (Blynk, MQTT, Google Assistant, web page).
3. Commands received from the app or voice service toggle the relays; manual switches can also be read so both work together.
4. The current state is published back so the app stays in sync with the physical switch.

Key Components and Their Role
- RP2040: dual-core Cortex-M0+ microcontroller with programmable I/O used for precise, low-level timing.
- Bluetooth Low Energy: short-range low-power wireless link to a phone or browser.
- microSD card module: storage for logs, audio or images over SPI.

Implementation Steps
1. Collect the components and study each module's datasheet (pin-out, voltage, interface).
2. Wire the circuit on a breadboard following the pin mapping; power sensors from the correct rail (3.3 V / 5 V).
3. Install C, Arduino IDE and the required libraries; flash a minimal test sketch for each module separately.
4. Write the main firmware: read sensors → process → drive outputs / send data.
5. Configure network or cloud credentials and test communication end-to-end.
6. Calibrate thresholds, add error handling (reconnect, sensor time-out) and run a long-duration test.
7. Finalise on a PCB / enclosure and document wiring, code and results.

Key Features
- App / web / voice control
- Real-time state feedback
- Manual override switches
- Multiple loads on one controller

Expected Output
On completion the student will have appliances that respond to app or voice commands within a second, with their state mirrored in the app.

Deliverables
- Complete source code with comments
- Circuit diagram and pin mapping
- Project report with screenshots and results
- Demonstration-ready build