Continuous Alcohol Monitoring Sensor Prototype

Project Overview

During my summer internship, I designed, built, and validated an amperometric driver circuit and bare metal firmware for a novel continuous alcohol sensor. This proof-of-concept demonstrates end-to-end data flow from chemical sensing through signal conditioning to live PC visualization, paving the way for a portable, low power continues alcohol monitoring device.

Key Contributions

• Circuit Design & Simulation
  • Developed an amperometric analog front-end in LTSpice, optimizing gain, bandwidth, and noise performance for the target sensor chemistry.
  • Researched and selected low-power precision op-amps and bias components to maximize sensitivity and battery life.
• Prototyping & Debugging
  • Assembled the amplifier and bias network on a breadboard; procured and used an oscilloscope to verify DC operating points and transient response.
  • Iterated component values to align real-world measurements with simulation.
• Firmware & Data Acquisition
  • Wrote bare-metal C for the Nordic nRF52 MCU: configured the ADC, DMA, and UART peripherals for continuous sampling and streaming.
  • Implemented calibration routines and basic digital filtering to improve signal stability.
• Data Visualization
  • Built a Python (PySerial + Matplotlib) tool to ingest UART data, plot live sensor readings, and log to CSV for post-processing.

Technologies & Tools

• Hardware: Nordic nRF52 (Arm Cortex-M4), precision op-amps, breadboard prototyping, oscilloscope
• Software: LTSpice, C (bare-metal), UART, Python (PySerial, Matplotlib)

This prototype laid the groundwork for miniaturized, battery-powered alcohol monitors capable of continuous, real-time readings in wearable and IoT applications.