Project

#	Title	Team Members	TA	Documents	Sponsor
52	LED Sphere Display	Ashley Saju David Heydinger Stephanie Eze	Shiyuan Duan	final_paper2.docx proposal1.pdf	LabEscape POV
	# LED Globe Display Team Members: - Ashley Saju(asaju2) - David Heydinger (ddh3) - Stephanie Eze (oeze2) # Problem For LabEscape, an escape room under Prof. Kwait, a unique LED display would be beneficial to the escape room experience. A spinning LED display should be able to show a timer count down and wirelessly show any image. # Solution We will design a curved LED strip to be mounted on a rotating platform that spins at a constant speed. Through a Bluetooth enabled app, we can upload images and text to the image display system for storage and playback. These images will be displayed using persistence of vision by precisely controlling LED light timing based on the angular position and speed of the platform. The position and speed of the platform will be measured by an Hall sensor that detects each revolution of the rotating system, allowing the system to accurately determine when to display certain LED lights. # Solution Components ## Image Displaying System (Microcontroller, Memory, and LEDs) This system handles the process of receiving the image wirelessly or taking a sprite from memory and lighting the LED appropriately. An SD card would be used to store sprites of numbers for the timer mode. Shift registers would be used to achieve a speedy parallel output to the LED. And the LEDs would be receiving a preset voltage at first then varying voltages if time allows for different colors. The potentiometer can be used to adjust LED color. RP2040 microcontroller Micro SD card > 16kB memory 24-bit Shift registers: STP24DP05 24-bit constant current LED sink driver with output error detection RGB LEDs: Strawhat LED 4.8mm RGB (4-Pin) WEDRGB03-CM 10kOhm Potentiometer with knob Resistors ## Wireless Control The ESP32 hosts a web application that is accessible by entering the device’s IP address into a web browser. This web application allows a user to upload text or an image, which are processed by the ESP32 into a display-ready format. The processed data is then transmitted directly from the ESP32 to the spherical display system for rendering. The initial implementation supports monochrome bitmap images, with plans to extend to multi-color images in future revisions. ESP32-WROVER-B ## Power System Delivering power to the stationary motor will be provided by AAA batteries. However, delivering power to the spinning component is more difficult due to the potential for wires to be tangled. To solve this, we will drive power to the rotating platform using a slip ring, allowing for 360 degree rotation without twisting any electrical connections. Components: AAA battery pack [MIKROE-5351] Power Switch [GSW-18] Slip Ring [ADAFRUIT1196] DC motor [CN-PA22-201213500-G429] Voltage Regulator (buck converter) ## Spinning PCB - angular speed measurement The spinning PCB will include a Hall effect sensor that will detect exactly when one full turn of the PCB has been completed. It will send the measurements to the microprocessor which will calculate the angular speed of the spinning PCB based on the time interval between measurements. Components: Hall effect sensor [US5881LUA] Voltage Regulator [MIC5219-3.3] Small Magnet [07045HD] # Criterion For Success Describe high-level goals that your project needs to achieve to be effective. These goals need to be clearly testable and not subjective. When operating at full speed, the displayed text and image should be clearly legible from 5 feet away over a period of 10 minutes. The rotating assembly remains balanced while operating, with no audible thumping exceeding 50 dB or visible oscillation for the duration of 10 minutes. The LED Globe successfully receives and displays image and text uploads within 1 minute per image, without requiring any physical connections. A Hall effect sensor accurately detects when the rotating assembly has completed one revolution, with less than 2% missed detections over 10 minutes. LED brightness is sufficient to display images and text from 5 feet away under standard indoor lighting (300 lux). Timer mode: Timer can be set to a time up to 1 hour in the web application and counts down, resets, and pauses via web application..

Electronic Automatic Transmission for Bicycle

Tianqi Liu, Ruijie Qi, Xingkai Zhou

Featured Project

Tianqi Liu(tliu51)

Ruijie Qi(rqi2)

Xingkai Zhou(xzhou40)

Sometimes bikers might not which gear is the optimal one to select. Bicycle changes gears by pulling or releasing a steel cable mechanically. We could potentially automate gear changing by hooking up a servo motor to the gear cable. We could calculate the optimal gear under current condition by using several sensors: two hall effect sensors, one sensing cadence from the paddle and the other one sensing the overall speed from the wheel, we could also use pressure sensors on the paddle to determine how hard the biker is paddling. With these sensors, it would be sufficient enough for use detect different terrains since the biker tend to go slower and pedal slower for uphill or go faster and pedal faster for downhill. With all these information from the sensors, we could definitely find out the optimal gear electronically. We plan to take care of the shifting of rear derailleur, if we have more time we may consider modifying the front as well.

Besides shifting automatically, we plan to add a manual mode to our project as well. With manual mode activated, the rider could override the automatic system and select the gear on its own.

We found out another group did electronic bicycle shifting in Spring 2016, but they didn't have a automatic function and didn't have the sensor set-up like ours. Commercially, both SRAM and SHIMANO have electronic shifting products, but these products integrate the servo motor inside the derailleurs, and they have a price tag over $1000. Only professionals or rich enthusiasts can have a hand on them. As our system could potentially serve as an add-on device to all bicycles with gears, it would be much cheaper.

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