Project
| # | Title | Team Members | TA | Documents | Sponsor |
|---|---|---|---|---|---|
| 10 | Automatic Music-Reactive Lighting System |
Annie Mak Disha Ghosh |
Eric Tang | ||
| # Automatic Music-Reactive Lighting System Team Members: - disha4 - anniexm2 # Problem Lighting plays a large part in setting the mood at events and small gatherings. However, manually adjusting colors, brightness, and movement to match a song requires constant attention. Preset effects may also miss changes in the rhythm or energy of the music. We want to create a device that automatically matches detected musical notes to colors, follows the rhythm through lighting effects, and adjusts brightness based on volume. The device should be simple to use and allow users to customize how the lighting responds to music. # Solution We propose an automatic lighting device with a microphone, a high-power RGBW LED light head, and a custom control PCB. The microphone will capture nearby music, and the microcontroller will estimate pitch, detect changes in audio energy, and measure volume. The device will start in an automatic mode without requiring a phone connection. The microcontroller will map estimated fundamental frequencies to musical notes and their assigned colors. Changes in audio energy will trigger lighting pulses, while the measured signal amplitude will control brightness. Pulse-width modulation (PWM) will independently control the red, green, blue, and white LED channels to produce mixed colors and smooth transitions. When the pitch estimate falls below a confidence threshold, the system will briefly hold its previous color to prevent unstable switching. The main focus will be audio processing, RGBW lighting, physical controls, and operation from our custom PCB. If time allows, we will add motors to move the light and Bluetooth controls to customize the settings! # Solution Components ## Main Control PCB Subsystem The custom PCB will connect and control the audio, lighting, and user interface subsystems. A Nordic nRF52832 microcontroller will process microphone samples and determine how the lights should respond. The software will check whether a pitch estimate is clear enough before changing the color. This will help prevent the light from rapidly switching between uncertain estimates. The final system will use individual chips and supporting circuitry mounted on our PCB rather than development boards. Components: - Nordic nRF52832-QFAA-R7 microcontroller IC - Clock crystal and supporting components - Programming and debugging header - Supporting resistors, capacitors, and connectors - Antenna circuitry if Bluetooth is included ## Audio Subsystem A microphone and amplifier circuit will capture nearby music and produce a signal the microcontroller can read. The circuit will amplify and filter the microphone output and keep it within the microcontroller’s input voltage range. The software will estimate the pitch of clear sounds and match it to the nearest musical note. Changes in audio energy will trigger lighting pulses, while volume will control brightness. Adjustable sensitivity will help reduce unwanted responses to background noise. Components: - PUI Audio POM-3535P-3-R electret microphone - Microchip MCP6002-I/SN operational amplifier - Bias and gain-setting resistors - Coupling and filtering capacitors ## Lighting Subsystem The light head will use a high-power RGBW LED to project colored light onto a nearby wall or surface. Controlling the four channels separately will allow us to create mixed colors and smooth transitions. Constant-current drivers will control the LEDs, and a heat sink will remove heat. A mixing optic will help blend the colors. We will choose the final LED operating currents and heat sink based on the brightness we need and the temperature measured during testing. Components: - Cree XLamp XM-L Color Gen 2 RGBW LED, with exact part number pending - TPS92512DGQR LED driver ICs, one per independently controlled color channel - Driver inductors, diodes, resistors, and capacitors - LED mounting PCB - Heat sink and thermal interface material - Mixing optic and light-head housing ## Power Subsystem An external DC adapter will power the device. We initially plan to use a 12 V input for the LED drivers, with regulated 5 V and 3.3 V supplies for any included motors and the control electronics. We will select the power supply based on the current needed by the LEDs, control circuit, and motors. Filtering and careful PCB layout will help prevent the lighting and motor currents from interfering with the microphone signal. Components: - External 12 V DC power adapter, with current rating selected after power calculations - LMR51430 buck regulator for the proposed 5 V supply, depending on motor current requirements - AP2112K-3.3TRG1 regulator for the 3.3 V supply - Power connector and switch - Input protection components - Filtering capacitors and test points # Additional Features ## Motion Control Subsystem If time allows, we will add positional servo motors to rotate or tilt the light head in response to rhythmic changes. We will start with side-to-side movement and add up-and-down tilt if the first axis works reliably. The motors will be selected based on the weight and balance of the LEDs, housing, and heat sink. Movement speed and travel will be limited to prevent the light head from hitting the housing or pulling on its wiring. Components: - Positional servo motors, with exact part numbers selected after load calculations - Rotation or pan-and-tilt brackets - Mounting hardware - Flexible wiring and strain relief ## User Interface Subsystem The device will have physical buttons or a knob to adjust brightness and microphone sensitivity. This will allow users to change basic settings without connecting a phone. If time allows, we will add a Bluetooth app using the nRF52832. The app would let users change the note-to-color assignments, sensitivity, brightness, and any included movement settings. Components: - Physical buttons or adjustment knob - Supporting resistors and capacitors - Bluetooth functionality through the nRF52832-QFAA-R7 if included - Optional phone app # Criterion For Success The project will be considered successful if it can: - Automatically respond to nearby audio without a phone connection or external computer. - Display the correct assigned color in at least 90% of repeated individual-note tests across one selected octave. - Change to the assigned color within 250 milliseconds after a sustained test note begins. - Produce a lighting pulse for at least 90% of the events in a test track with evenly spaced percussive sounds. - Produce increasing brightness when the same audio is played at three increasing volume levels from a fixed distance. - Control all four LED channels independently and demonstrate fades between assigned colors. - Run from the custom PCB for at least 15 minutes without resets or exceeding the components’ operating temperature limits. If Bluetooth is included, users should be able to change brightness, sensitivity, and color assignments while the device continues running. |
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