# Title Team Members TA Documents Sponsor
4 Electronic Automatic Transmission for Bicycle
Ruijie Qi
Tianqi Liu
Xingkai Zhou
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.

RFI Detector

Jamie Brunskill, Tyler Shaw, Kyle Stevens

RFI Detector

Featured Project

Problem Statement:

Radio frequency interference from cell phones disrupts measurements at the radio observatory in Arecibo, Puerto Rico. Many visitors do not comply when asked to turn their phones off or put them in airplane mode.


We are planning to design a handheld device that will be able to detect radio frequency interference from cell phones from approximately one meter away. This will allow someone to determine if a phone has been turned off or is in airplane mode.

The device will feature an RF front end consisting of antennas, filters, and matching networks. Multiple receiver chains may be used for different bands if necessary. They will feed into a detection circuit that will determine if the power within a given band is above a certain threshold. This information will be sent to a microcontroller that will provide visual/audible user feedback.

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