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spotlight

Final sensor iteration in the field
Final sensor iteration internals

Earlier sensor revisions, using laser TOF
Auxiliary sensor unit pictured in second

Web interface for accessing sensor data

Aquametric ↗

Low cost and distributed stream and river monitoring.

Project Page ↗
Github ↗

  • Designed hardware and embedded software
  • Sensor reports stream stage, temperature and conductivity data on an hourly basis through a cellular data connection
  • Optimized device cost to sub-$100
  • Collected data in the field for >6 months, validating sensor design
  • Worked with school’s environmental science department to ensure its viability for research purposes

Embedded

  • Analyzed and optimized power usage to extend battery life to approximately 18 months in the field
  • Designed and assembled a custom PCB for the final sensor version to improve stability in the field.
  • Initially experimented with LoRa and SMS for communication, before settling on cellular data
  • Developed modular auxiliary sensor port for additional sensors like temperature and conductivity
  • Experimented with laser ToF and capacitive water level sensing before settling on ultrasonic time of flight
  • Early revisions used a solar-power based trickle charge system to extend battery life

Software

  • Developed early prototypes of the backend and produced the final user interface
  • Developed asynchronous communication method allowing for in-field configuration of device parameters and OTA updates
Hardware diagram when worn on ankle
Unrolled hardware diagram
Finished wearable device, unrolled
Exposed wearable electronics
(microcontroller, bluetooth module, 3 DoF compass and 1 of 3 laser ToF sensors pictured)

Foresight ↗

A wearable device to aid in navigation and obstacle avoidance for the blind.

  • Won the Regeneron Health Award at the Greater Capital Region Science and Engineering Fair in 2018
  • Designed wearable device and embedded software
  • Ankle mounted array of sensors and haptic motors communicates via Bluetooth to an Android device
  • Haptic vibrations on the ankle indicate the direction the user should turn to continue on their route, generated by Google Maps
  • Laser ToF sensors measure distance to nearby obstacles. The user is alerted to these by a series of haptic vibrations, corresponding to the distance of the approaching object
  • Designed electronics to reduce device bulk, enabling it to fit comfortably under a pant leg
  • Sequentially powered I2C devices allows simultaneous measurement from ToF sensors
  • Multiplexed microcontroller outputs control the 8 haptic vibration motors
Basic mechanical design

Skeleton and completed device

Electrical system

Spiffy ↗

A robotic system to automate the patient room cleaning process in hospitals.

  • Designed robotic platform and embedded software
  • Developed skills in power electronics controlling the on-board drive motors with ESCs
  • Designed relay control circuits for switching the pump and UV flood lamp
  • Created a serial protocol for communication between the on-board Raspberry Pi and Arduino with error correction
  • Implemented basic PID control loops for controlling wheel speeds smoothly