Week 1 Activity - Acquiring data

For our Week 1 lesson, we were tasked to build a standalone pH sensor with an Arduino, a LCD screen, and a pH probe.

pH sensors are used to measure the acidity or alkalinity of a solution. In the case of the oceans, the acidity or alkalinity of the water determines how underwater ecosystems can thrive in the particular area.

Using a program we created for the Arduino microcontroller, we measured the pH values of 3 solutions with a known pH in order to calibrate the sensors. The input and output signal pins, of the Arduino, used for the LCD display are pins 8, 9, 4, 5, 6 and 7.

 Here are some pictures of the calibration process:

The data our team obtained are as follows:

Yellow - 7.038

Blue - 9.579

Red - 4.104

The coding is then modified to include an alarm that will be triggered when pH of more than 7 is detected. A buzzer, which is connected to pin 11 of the Arduino, is used to indicate this.

When the pH sensor was inserted into the blue solution, a "high" warning appeared on the LCD and the buzzer started buzzing as intended. 

  

For the last part of the week 1 class assignment, our group decided to compare the pH sensor, refer to figure 2, to temperature sensor, refer to figure 1.

Figure 1: Temperature Sensor

Figure 2: pH Sensor (Atlas Scientific, 2016)

Q1 Is there any difference in the type of output signals of the sensor? Does it affect the selection of the port to which it is interfaced with the Arduino?

As compared to the temperature sensor which uses digital signals, pH sensors uses analog signals.


Q2 How does the calibration procedure of our sensor differ from that of the other type of sensor?

For the temperature sensor, it is already calibrated, making the calibration procedure simple. As for the pH sensor, the sensor had to be placed in a solution that had a know pH. After that, a command is sent to the sensor for calibration.


Q3 Why is it necessary to monitor the parameter of the other type of sensor in lakes or process industry?

As the name suggests, temperature sensor measures the temperature. It is widely used in the process industry as certain products need to be kept at a optimal temperature when manufacturing in order to get the ideal quality. The temperature sensor enables manufacturing workers to monitor the temperature of the product and to act accordingly should the temperature is not of the optimal value.


References

• Atlas Scientific (2016) pH Kit  Available at: http://atlas-scientific.com/product_pages/kits/ph-kit.html  (Assessed 22nd October 2016)

Keith

Let's get started!

Welcome!

This blog will chronicle Group 2's journey in the Engineering & Design module, a component of Singapore Polytechnic's Engineering Academy Programme, as we set out to build a submersible vehicle capable of transmitting photos.

In this blog, we intend to share the story of our project, along with what we have learnt in our weekly activities, as well as the thought processes behind the design decisions of our project.

Ah right, how could I forget my manners, who are Group 2?

We are:

• Lucas
• Pei Yong
• Joel
• Gabriel
• Keith

On behalf of the five of us, I welcome you to this blog, and we look forward to sharing our journey with you!

Lucas