Solution: Microcontroller-Based DAQ System

Definition

A microcontroller-based DAQ system uses a microcontroller to acquire, digitize, process, store and/or transmit sensor data.

Architecture

Sensor
  ↓
Signal Conditioning
  ↓
ADC ───────────────┐
  ↓                │
Microcontroller ← Timers / Interrupts
  ↓
Data Processing
  ├──→ Display
  ├──→ Memory / SD Card
  └──→ UART / SPI / I²C / USB → Computer/Network

Working

1. A sensor measures the physical quantity.
2. Signal conditioning amplifies and filters the sensor output.
3. The ADC converts the analog signal to digital data.
4. The microcontroller samples the data at a programmed rate.
5. Firmware performs scaling, calibration, filtering or feature extraction.
6. The processed data is displayed, stored or transmitted.
7. The controller can also generate control outputs based on measured data.

Important Components

• Sensors/transducers
• Signal-conditioning circuits
• ADC
• Microcontroller
• Timers and interrupts
• Memory/storage
• Communication interfaces
• Display or actuator interface

Advantages

• Compact and low cost.
• Programmable and flexible.
• Easy data logging.
• Real-time processing.
• Multiple communication options.
• Suitable for portable biomedical and industrial instruments.

Example: Temperature Logger

Temperature Sensor
       ↓
Amplifier + Low-pass Filter
       ↓
ADC
       ↓
Microcontroller
       ↓
Convert Code → Temperature
       ↓
SD Card / LCD / USB

The microcontroller periodically samples the temperature, converts the ADC code into temperature units, adds a timestamp and stores the result.

Conclusion

A microcontroller-based DAQ integrates measurement, conversion, processing, communication and storage into a compact embedded system.