Project
# | Title | Team Members | TA | Documents | Sponsor |
---|---|---|---|---|---|
70 | Automatic Drum Tuner |
Joey Bacino Jonathan Fejkiel Max Wojtowicz |
Shengyan Liu | proposal1.pdf |
|
Members Joey Bacino - jbacino2 Jonathon Fejkiel - jfejkiel2 Wojtowicz - mwojt3 Problem Playing instruments is a pastime enjoyed by millions of people across the world. A task that almost every musician must endure before playing is tuning their respective instrument. For many this is done easily if they are of able body and have good pitch. However, turning lugs and listening for the right tune can be difficult if someone is weaker such as a child or the elderly, or if they are inexperienced in hearing perfect pitch such as a beginner. Solution The solution we propose is an automatic tuner for instruments that will adjust the instrument until the desired pitch is reached. We will specifically design our tuner for use on drums. The device will strike the drum, listen for the pitch, calculate how much it should either tighten or loosen the drum, and instruct a motor to do so. It will perform extra checks to ensure the drum was adjusted properly. Additionally, the mechanism will connect to a mobile app to select pitch if time permits. Subsystem 1 Power Management System: To have enough power for striking the tuning hammer and turning the pegs of the drums, we will utilize a power tool battery such as a Milwaukee M12 battery system. The same battery will power the microcontroller and sensors so it must be regulated to the correct voltages to ensure the safety of the components and the user as well. The power management subcircuit will have over-current and over voltage components such as fuses and diodes to ensure circuit protection. A buck converter will step the 12V supply down to the required inputs of the rest of the components. Subsystem 2 Drum Striking Hammer: For the motor that drives the hammer that would strike the drum, we will use a push-pull solenoid. We’re choosing a push-pull solenoid because they can provide a consistent and quick tap. Consistency is important around the entire drum, we need to make sure each strike is the same for every single hit on every single lug we would like to tune. A quick tap also allows the drum to resonate fully and not dampen the hit by leaving the hammer on the drum head. This is important because we want our pitch detection to be able to hear the purest/most dominant tone around each lug without any type of interference. Minimizing overtones will simplify our pitch detection system as we want as close to only one tone at any given time. Also, we would experiment with different materials such as rubber, wood, and felt to see which gets us the best result for our hammer. Subsystem 3 Pitch Detection: To detect the pitch of the drum at its current state, a microphone will begin to read the input of audio after the hammer has struck. The returned sound snippet will be recorded and the raw audio data will be converted to frequency domain data on the microcontroller. This can be done using a Fast Fourier Transform algorithm on the microcontroller. The dominant frequency will be noted as the pitch of the drum. Based on the input for the desired note, the microcontroller will then decide if the drum needs to be tightened or loosened and by what amount. Subsystem 4 Tuning Motor Control: For the motor that would be turning the lugs, we want to use a high-torque servo motor. High torque is a requirement for this part because when you want to tune your drum higher and higher, you need more and more torque as the drumhead provides more and more resistance against the tuning lugs. Servo motors also offer very precise control with feedback, so we could calibrate the motor to each lug and precisely determine how much the pitch changes with how much rotation. Subsystem 5 Pitch Correctness LEDs: The device will have LEDs that will indicate to the user if the current pitch of the drum is correct, close, or far off from the desired pitch. It will begin lighting when the drum is first struck. Every time the drum is struck after a pitch adjustment, the LEDs will display a different color so that the user will know the progress of the tuning. Green will be displayed and stay lit once the device has finished tuning to indicate to the user that they are ready to play. While the device is not in an active tuning task, the LEDs will stay lit blue to indicate a standby mode. Criterion For Success Our first criteria for success will be being able to accurately detect the pitch from our pitch detection system, as that will be the basis for how the two motors act. Another criteria for success will be repeatability, our system should return consistent pitch readings and tuning results across multiple tests. The second criteria is the accurate striking of the drum. This can not be too fast or slow, and must be the correct length of time. One more can be our lug-turning motor being able to accurately turn the lugs to the desired pitch without too many intermediate hammer strikes and adjustments. We also want minimal noise and interference from our motors. |