Week6

Week 6 Progress: Functional Testing and Hardware Integration

Objective:
To test all essential functionalities of the newly assembled circuit board, including analog signal acquisition, power stability, and microcontroller operation. Finalize hardware integration by mounting the system onto a flexible wearable base.

Implementation:

  • With soldering complete, I carried out basic functional testing on all major subsystems of the board:

    • Power module (battery and Type-C charging)

    • nRF52840 microcontroller

    • Analog inputs from flex sensors

    • Op-amp impedance buffer circuit

  • Microcontroller check:

    • After replacing the previously damaged board in Week 5, the new nRF52840 was connected via USB.

    • A minimal test sketch was uploaded to validate analog input functionality and BLE advertising.

    • Serial output and onboard LED feedback were used to verify the program was running correctly.

  • Analog input test:

    • Connected flex sensors and manually bent them to simulate ankle movement.

    • Readings were printed over serial and monitored using Arduino Serial Plotter.

    • Verified stable voltage response from flex sensors through op-amp circuit (smooth output, no spikes).

    • All pins mapped correctly, and no wiring issues were found.

  • Final hardware integration:

    • After confirming that all components were functioning correctly, the system was mounted onto a flexible plastic carrier, aligned for wearable use.

    • Wiring was adjusted and secured for comfort and safety.

Results:

  • All analog and power circuits passed functionality testing.

  • The microcontroller successfully booted, read analog inputs, and broadcasted BLE signals, confirming readiness for firmware development.

  • The hardware system is now fully integrated and ready for real-time monitoring implementation in Week 7.



Code Description:
The test code was designed to verify the analog input functionality of the Seeed Studio nRF52840 microcontroller. It continuously reads voltage values from the flex sensor connected to analog pin A0 and prints the results to the serial monitor.

By manually bending the flex sensor during the test, changes in resistance were translated into voltage variations. These variations were successfully captured as fluctuating ADC values in the serial output. A stable signal response and smooth voltage curve confirmed that both the analog input circuit and op-amp buffer were functioning correctly.









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