Transcript
Abstract:
CycleTooth is a Bluetooth enabled device that contains all the necessary hardware to determine the state of charge of the batteries of an electric bicycle. CycleTooth attaches to the electric bike, has the capability to estimate the amount of energy remaining in the batteries, and is equipped with Bluetooth to transmit its data. In essence, CycleTooth will act as a fuel gauge.
The initial motivation behind CycleTooth is the problem of accurately knowing the state of charge (SOC) of the batteries on an electric bicycle. There are a couple things that need to be cognizant to determine SOC: • Metering current draw and battery voltage. To create a viable product CycleTooth provides • Bluetooth communication capability.
CycleTooth design goals: • Design to Cost • Bill of materials (BOM) cost: <$33 • Schematic and Board Layout • Printed Circuit Board • Surface mount components • Reflow soldering • Affordable • Versatile • Effective • Efficient
The CycleTooth hardware contains 74 components and a final BOM cost of $32.06 and includes: • Picaxe microcontroller • High voltage switching regulator (18100 VDC) • Current sensing • Hall effect • Current shunt • Signal conditioning • Voltage measurement • Temperature sensor • Bluetooth transceiver chip • PCB trace antenna All implemented on a 2 x 4 inch printed circuit board using surface mount technology and reflow soldering.
This development board will help future designers create viable solutions in the burgeoning field of electric drive transportation. CycleTooth will play an important role in facilitating that progress. Possible development: • Android apps that receive data from CycleTooth. Provides energy usage; numeric percentage of battery charge. • Finding more effective SOC algorithms; Ah integration, opencircuit voltage, Kalman estimation. • Look-up table for multiple kinds of batteries
