Week 17

5/02/2026

I tested the servo motors for the feeding mechanism. I had two options: a larger 12V servo and a smaller 5V servo. The 12V servo was unnecessarily large for dispensing fish food. The 5V servo was compact and sufficient for rotating a small feeding container.

The servo was powered from the 5V rail, grounded to the common ground, and the signal pin connected to GPIO 27.

I programmed it to rotate to a specific angle and then return to its original position. Initially, there was slight jitter, which I suspect was due to power instability. After ensuring proper grounding and stable 5V supply, the movement became smoother.



Comments

Post a Comment

Popular posts from this blog

Week 4

Image
12/10/2025 This week I moved on to testing the pH sensor module. The module was powered from the 5V rail, with ground connected to the common ground rail, and its analog output connected to GPIO 36, which is one of the ESP32’s ADC input pins. I learned that the ESP32 converts analog voltage (0–3.3V) into digital values using its ADC. Therefore, I needed to map the raw ADC readings into pH values after calibration. At first, the readings were unstable and fluctuating. After some research, I understood that the pH probe requires time to stabilise in water and also needs calibration. After adjusting the calibration potentiometer on the module and allowing the probe to sit in water, the readings became more consistent. 14/10/2025 I started working with the relay module. The relay board was powered using 5V and GND from the breadboard rails, and the control pins were connected to GPIO 25, 26, and 27. I wrote a simple test program to switch each relay channel ON and OFF. At first, the relay...
Read more

Week 2

Image
 1/10/2025 After meeting with my supervisor, I learnt the following: -The need to complete the risk assessment before starting anything with the project.  -No ethical approval is required as the project will not deal with people or animals. -The project objectives should be specific, as mine were general. -The need to complete the project plan as soon as possible.  As a start, the risk assessment was completed. Water and soldering were the major risks for the project, but under the appropriate control, they can be avoided.  2/10/2025 The next task for me is to set specific objectives for the project. The system should be able to change the water regularly, dispense food, maintain the optimal water quality, and indicate important values using IoT. To set specific objectives, I should answer the following questions: -What type of fish will the system be suitable for? -How often should the water be changed? -What percentage of the water will be changed? 100?! -How ...
Read more

Reference

 FISH OPERATING RANGES Guppy: Temperature range: 22°C to 28°C pH range: 6.8 to 7.8 Goldfish: Temperature range: 18°C to 24°C pH range: 7.0 to 8.4 Tetra: Temperature range: 22°C to 27°C pH range: 6.0 to 7.5 HARDWARE CONNECTIONS Temperature Sensor (DS18B20): VCC connected to 3.3V GND connected to GND DATA connected to GPIO 4 A 4.7kΩ pull-up resistor is placed between DATA and 3.3V Ultrasonic Sensor (HC-SR04): VCC connected to 5V GND connected to GND TRIG connected to GPIO 18 ECHO connected to GPIO 19 through a voltage divider Relay Module (ESP32 Control Pins): Channel 1 (Heater) connected to GPIO 26 Channel 2 (Fan) connected to GPIO 25 Channel 3 (Drain Pump) connected to GPIO 33 Channel 4 (Fill Pump) connected to GPIO 32 OLED Display (I2C): VCC connected to 3.3V GND connected to GND SDA connected to P21 SCL connected to P22 I2C address 0x3C pH Sensor: VCC connected to 5V GND connected to GND Analog output connected to GPIO 34 Servo Motor: VCC connect...
Read more