Embedded Systems Projects in Bangalore

An ATmega328P microcontroller reads AC voltage and current via a ZMPT101B voltage sensor and ACS712 current sensor, computes real power using the trapezoidal integration method, and accumulates energy in kWh. A SIM800L GSM module transmits monthly consumption data as an SMS to the utility server and the consumer's registered mobile number. A 16×2 LCD displays real-time voltage, current, power factor, and cumulative units. The firmware is written in bare-metal C with interrupt-driven ADC sampling at 2 kHz, achieving a measurement accuracy of ±1.5% against a calibrated reference meter.

A FreeRTOS application running on an STM32F103C8T6 manages three concurrent tasks: a PID control task that reads a PT100 RTD via a MAX31865 SPI interface and drives a solid-state relay, a data-logging task that writes temperature samples to a microSD card over SPI at 1 Hz, and a display task that refreshes a 128×64 OLED every 500 ms. Task priorities and stack sizes are tuned to ensure the control loop executes within a 10 ms deadline. The project demonstrates preemptive scheduling, mutex-protected SPI bus sharing, and watchdog-timer recovery.

An embedded system based on the PIC16F877A microcontroller controls a bank of twelve street lights using LDR-based ambient-light sensing and a real-time clock module for schedule-based override. Each light circuit is monitored by a current-sense resistor; an open-circuit or short-circuit fault triggers an alert stored in EEPROM and transmitted via RS-485 to a central monitoring PC. The firmware implements a finite-state machine with five states: day-off, dusk-on, night-on, fault, and maintenance. Power consumption is reduced by 40% compared to a manual timer-based system in field trials.

Four sensor nodes — engine temperature, oil pressure, fuel level, and vehicle speed — each built around an ATmega168 with an MCP2515 CAN controller, transmit data frames at 500 kbps over a twisted-pair CAN bus to a central dashboard node. The dashboard node, running on an STM32F4, decodes incoming frames, applies calibration coefficients, and renders gauge graphics on a 3.5-inch TFT display. Error frames and bus-off recovery are handled per ISO 11898. The project demonstrates multi-node embedded design, CAN protocol implementation, and real-time display rendering.

A soil moisture sensor node built around an ATtiny85 wakes every 15 minutes from deep sleep, reads a capacitive soil moisture sensor via ADC, and transmits a 12-byte LoRa packet at SF7/BW125 to a gateway 2 km away. The node draws 1.8 µA in sleep mode and 38 mA during the 200 ms transmission window, yielding a calculated battery life of 18 months on two AA cells. The gateway forwards packets to a Node-RED dashboard over MQTT. The project covers ultra-low-power firmware design, LoRa link budget calculation, and IoT protocol integration.

A load cell interfaced through an HX711 24-bit ADC connects to an Arduino Uno that performs tare, calibration, and weight computation in firmware. The system displays weight on a 7-segment display and transmits readings over UART to a Python script on a PC that logs data to a CSV file with timestamps. Calibration coefficients are stored in EEPROM so they survive power cycles. The project achieves a resolution of 0.1 g over a 5 kg range and includes a PC-side GUI built with Tkinter for real-time plotting and data export.

An R307 optical fingerprint module communicates with an STM32F103 over UART to enrol and verify up to 127 fingerprints. On successful match, the system logs the employee ID and timestamp to a microSD card and displays the name on a 20×4 LCD. An unmatched attempt triggers a buzzer alert and increments a failed-attempt counter stored in EEPROM. A Python script on a connected PC parses the CSV log and generates daily attendance reports in Excel format. The project covers biometric sensor integration, UART protocol handling, and file-system management on embedded hardware.

A closed-loop DC motor speed controller implemented on an ATmega32 uses a quadrature encoder to measure actual RPM and a PID algorithm to adjust the PWM duty cycle driving an L298N H-bridge. The desired setpoint is entered via a 4×4 keypad and displayed on an LCD. The PID gains are tunable at runtime without reflashing firmware. Step-response tests show a settling time of 120 ms and zero steady-state error at setpoints between 100 and 3000 RPM. The project demonstrates real-time control theory implementation on a resource-constrained microcontroller.

An Arduino Mega manages a 20-slot parking facility using IR break-beam sensors at each slot to detect occupancy. Entry and exit gates are controlled by SG90 servo motors. An I2C LCD at the entrance displays available slots in real time. Slot occupancy data is transmitted over Wi-Fi via an ESP8266 to a Firebase Realtime Database, enabling a companion Android app to show live availability. The firmware handles sensor debouncing, servo PWM generation, and Wi-Fi reconnection logic within a cooperative task loop.