🎓 Instrumentation Course - Spring 2026 (1405)

Comprehensive Assignments, Mathematical Modeling, Circuit Simulations & STM32 Firmware

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📚 About This Repository

This repository contains homework assignments, mathematical modeling, circuit schematics, Proteus simulations, and STM32 C firmware for the Instrumentation course taught by Dr. Mohammadreza Nayeri at the University of Tehran (Spring 1405 / 2026). The projects cover sensor calibration, signal conditioning, active filtering, data acquisition, and embedded microcontroller control.

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📋 Homework Overview

🔹 HW1: Sensor Data Analysis & Curve Fitting (MATLAB)

Topic: Statistical analysis of sensor data, calibration, and error modeling.

• Q1: Statistical analysis of raw sensor data (Mean, Variance, Standard Error).
• Q2 & Q3: Least Squares (LS) and Recursive Least Squares (RLS) fitting (degrees 1, 3, 9) and convergence rate comparison.
• Q4: Hysteresis analysis and calculation of %FS hysteresis error.
• Q5: Thermal drift rate quantification (Zero Drift $8\text{ mV/}^\circ\text{C}$, Sensitivity Drift $-2\text{ mV/(mm}\cdot^\circ\text{C})$) and 2nd-order dynamic system identification. 👉 Read HW1 Full README

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🔹 HW2: Dynamic System Simulation & Signal Conditioning (Simulink + Proteus)

Topic: Modeling measurement systems, Op-Amps, active filters, and bio-potential amplifiers.

• Q1: 1st and 2nd order system modeling in Simulink and $50\text{ Hz}$ LC Notch filter noise suppression.
• Q2: Multi-stage LM324 Op-Amp comparator circuit for NTC thermistor temperature thresholding.
• Q3: 4-Bit R-2R DAC, 74HC161 staircase generator, RC low-pass filter, and 74HC191 Up/Down counter triangular wave generator.
• Q4: 4-Stage ECG Bio-Potential Instrumentation Amplifier ($5000\times$ Gain, $10-100\text{ Hz}$ BPF, CMRR $50\text{ Hz}$ noise rejection, AD620 Wheatstone bridge). 👉 Read HW2 Full README

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🔹 HW3: Timers, EXTI Interrupts & Sensor Interfacing (STM32 + HAL)

Topic: Embedded C programming with STM32CubeMX, Timers, EXTI interrupts, and ADC classifiers.

• Q1: Common Cathode 7-Segment Elevator floor display with zero-latency EXTI emergency holds (PB1 / PB2).
• Q2: $1\text{ kHz}$ TIM2 PWM DC Motor speed scaling via 12-bit ADC and L298 driver direction toggling.
• Q3: Precision $500\text{ ms}$ TIM3 Timer Interrupt countdown system with 16x2 LCD display, $1\text{ Hz}$ alarm, and reset switch.
• Q4: Automatic Industrial Sensor Classifier (LM35 Temp, HIH-4000 Humidity, MPX4115 Pressure, MQ-135 Gas) via 12-bit ADC. 👉 Read HW3 Full README

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🔹 HW4: Temperature Sensors, Load Cell & I2C Protocol (STM32)

Topic: Transducer physics (RTD, Thermocouple, Thermistor), I2C digital sensors, and loadcell digital scale.

• Q1: Multi-sensor temperature characterization (PT100 4-wire RTD $1\text{ mA}$ current loop, Type K Seebeck amplifier $A_v=100$, NTC Thermistor $\beta=4804\text{ K}$).
• Q2: I2C Communication with LM75 digital temperature sensor (`0.5^\circ\text{C}$ resolution) and LCD integration.
• Q3: Load Cell & Digital Scale implementation ($0-2\text{ kg}$ Loadcell, 3-Op-Amp Inst Amp $A_v=500$, 2nd-order damped vibration simulation, active LPF $f_c=0.5\text{ Hz}$, EXTI zero-offset Tare calibration). 👉 Read HW4 Full README

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🔹 HW5: Motor Drivers, Distance Sensors & Encoder Decoding (STM32)

Topic: Electromechanical actuation, Time-of-Flight rangefinding, Optocounters, and Quadrature Encoder decoding.

• Q1: DC Motor speed and direction control using L293D H-Bridge driver and PWM duty cycle modulation.
• Q2: Solar Tracker Panel angle control using $1.8^\circ$ Stepper Motor and ULN2003A driver (Manual mode, Auto tracking $1.8^\circ / 2\text{ s}$, high-speed $10\text{ ms}$ Reset rewind, Full-Step vs Half-Step analysis).
• Q3: ToF Ultrasonic Distance Meter ($d = \frac{t \cdot 0.034}{2}\text{ cm}$) and active reflection IR proximity obstacle sensor.
• Q4: Potentiometer angle sensing ($0.0659^\circ$ resolution), Optocounter speed sensing ($N = 23$ slots), and Incremental Rotary Encoder Quadrature Decoding (1x, 2x, and 4x modes down to $0.342^\circ$ resolution). 👉 Read HW5 Full README

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🔹 HW6: Advanced Environmental Sensors & Telemetry (STM32 + IoT)

Topic: Gas chemiresistors, single-wire climate sensors, turbine flow meters, and USART serial telemetry.

• Q1: MQ-4 Methane/Natural Gas Sensor ($\text{SnO}_2$ heated semiconductor physics) with $D_0$ digital leak alarm.
• Q2: DHT11 Climate Controller with non-blocking multi-menu LCD interface, proportional PWM fan speed control ($\Delta T$), and independent heater/humidifier feedback.
• Q3: LDR Light Module sensitivity thresholding ($SRV = 10\text{ k}\Omega$, Threshold = 1, 3, 5).
• Q4: Turbine/Hall-Effect Pulse Flow Rate Meter ($f = 7.5 Q \implies Q = \frac{f}{7.5}\text{ L/min}$).
• Q5: MPX4115 Absolute Pressure Sensor ($V_{\text{out}} = V_s(0.009P - 0.095)$) with 12-bit ADC quantization.
• Q6: Industrial Water Tank Liquid Level Control ($< 25%$ critical threshold, L293D DC motor pump, dual status LEDs).
• Q7: BMP180 Barometric Pressure & Altitude Sensor ($h = 44330 \left(1 - (P/P_0)^{0.1903}\right)$) with USART1 Virtual Terminal stream and $>40^\circ\text{C}$ over-temperature warnings. 👉 Read HW6 Full README

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🛠️ Tools & Technologies

Category	Tools & Hardware
Microcontrollers	STM32F103C8T6 (Blue Pill), STM32F103R6 (ARM Cortex-M3)
IDE & Toolchain	STM32CubeIDE, Keil uVision, STM32CubeMX
Simulation	Proteus 9 Professional, MATLAB R2025b, Simulink
Libraries	STM32 HAL Library, CMSIS
Sensors	DHT11, BMP180, HC-SR04, Sharp IR, MQ-4, MQ-135, LM75, PT100 RTD, Type K Thermocouple, NTC Thermistor, LDR, Load Cell, Hall Flow Turbine
Actuators & Drivers	DC Motors, Servo Motors, 1.8° Stepper Motors, L298 H-Bridge, L293D H-Bridge, ULN2003A Darlington Array

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📂 Repository Structure

Instrumentation-Course-Spring05/
├── HW1/          # Sensor Data Analysis & Curve Fitting (MATLAB)
├── HW2/          # Simulink & Proteus Active Filters, Op-Amps & ECG Amplifier
├── HW3/          # Timers, EXTI Interrupts, PWM Motor & ADC Sensor Classifier
├── HW4/          # Temperature Sensors, LM75 I2C & Digital Scale
├── HW5/          # DC/Stepper Motors, Ultrasonic/IR & 4x Encoder Decoding
├── HW6/          # Advanced Environmental Sensors, DHT11 & BMP180 Altitude
├── LICENSE       # MIT License
└── README.md     # Main Repository README

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🚀 How to Run

For MATLAB Assignments:

cd HW1/
run curveFit.m  % Or any other script

For STM32 Assignments:

1. Open target project in STM32CubeIDE.
2. Load the corresponding .ioc configuration file.
3. Build project (Ctrl + B) to generate output .hex binary.

For Proteus Simulation:

1. Open the .pdsprj file in Proteus 9 Professional.
2. Assign the compiled .hex file to the microcontroller component.
3. Click Play to start the simulation.

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📊 Reports & Results

Each homework directory includes complete, professionally written LaTeX PDF reports:

• HW1/Inst-HW1-810102443.pdf
• HW2/Instr-HW2-810102443.pdf
• HW3/Inst-HW3-810102443.pdf
• HW4/Instr-HW4-810102443.pdf
• HW5/Report.pdf
• HW6/Report.pdf

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👨‍💻 Author

Amirali Dehghani | Electrical Engineering Student (Control)
University of Tehran, School of Electrical & Computer Engineering

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📝 License

This project is licensed under the MIT License. See the LICENSE file for details.

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