Week 3 (Start of hardware development)

 5/10/2025

After finalising the SMART objectives, I started working on the practical setup of the system. Before connecting any sensors, I placed the ESP32 on the breadboard and connected its 3.3V, 5V, and GND pins to the long power rails on the breadboard. This was done so that any component can later be powered easily without repeatedly connecting wires directly to the ESP32. It also makes the wiring more organised and reduces mistakes.



When I first tried uploading code using the Arduino IDE on my personal laptop, I faced issues with the ESP32 board libraries. The board was not recognised properly and some required libraries were not compiling. To check whether the problem was hardware or software related, I tested the same setup using the university lab PC. The code compiled and uploaded successfully there, which confirmed that the issue was with my laptop.

For a short period, I was only able to test and upload code during lab hours. Later, after reinstalling the Arduino IDE and properly installing the ESP32 board package and libraries, I managed to fix the issue on my laptop. From that point onward, I was able to work more flexibly.

7/10/2025

I began testing the DS18B20 temperature sensor. The sensor was powered from the 3.3V rail and connected to GPIO 4 for data. A 4.7kΩ pull-up resistor was added between the data line and 3.3V, as required for OneWire communication.

Initially, the sensor was not detected. I first suspected a coding error, but after checking the wiring carefully, I found that the data wire was not properly connected. Once corrected, the sensor started responding correctly.

I used the serial monitor to print temperature values and observed that the reading changed when I touched the sensor, confirming that it is responsive and accurate.

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Week 2

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Reference

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