Progress of project

22/6–28/6, Week 7

Our team was faced with major difficulties in proceeding with the project.

1. The original pump ordered is not suitable, so a new pump was purchased with higher pressure (2.8 bars) and flow rate (3.5 L/min) to support the head of a person (usually 5 kg).

2. It is challenging to uniformly cut open the pillow, and the memory foam is a great insulator, so the surface temperature barely changes, placement of the pouch might be changed to on top of the pillow and covered with a pillowcase.

3. A plastic container is not the most suitable for the Peltier module, so a metal one is purchased with the plastic container to be used to store electronics

4. The original pump is very noisy; noise insulation is to be considered

5. Challenges on many other technical issues, like connecting the pump to Arduino and the power source, due to a lack of expertise.

Plan for the next week:

Figure out the water circulation system when the new pump arrives, the placement of the water pouch in the pillow and if time allows, work on the Peltier module.

29/6-5/7, Week 8

We experimented with the Peltier module and realised it could not be connected to an Arduino. With some help from the PhD students, we mapped out the placement of different components and drew a block diagram. We then purchased drivers and a temperature sensor probe to monitor the water temperature over time.

The water pump did not arrive in time due to the seller being unresponsive and the delay in shipment.

We created a new diagram for better clarity and tested the cooling capacity of 2 Peltier modules, this will be further calibrated once the pump and sensor have arrived. We have learned that ventilation is required to allow the heat sink and fan to properly function and hence will be drilling holes in the plastic container. We will also ensure proper insulation of the metal tin with either memory foam or bubble wrap.

Plan for the next week:

Pray that the water pump arrives so we can finally test the circulation system, if not just work on our Peltier module, as the sensors and drivers have arrived.

6/7-12/7, Week 9

The water pump has not arrived 🙁

13/7-19/7, Week 10

We drew out the block diagram and figured out how to connect all the components together using the Arduino and Mosfet Drivers to help power all our separate components.

We also tested the Arduino code we had coded, which used the IDE system to power on the different components of our smart pillow. It worked to what we had coded, but more has to be done for it to work for our plans.

Unfortunately, our team had faced two different issues this week. First, the pouch was insufficiently sealed, which required us to reseal it and try a different method of sealing. Furthermore, we realised that the Peltier cooling system we had used was very inefficient as the Peltier modules were heating up each other. So we decided to adapt to using just one Peltier module and a CPU cooler.

Plan for the next week:

Test out the whole system and the efficiency of the new Peltier cooling system.

20/7-26/7, Week 11

We tested out the CPU cooling system with our Peltier and managed to get better cooling, which was sufficient for our project. But the CPU cooler with fan was very unstable with the metal tin on top. So we decided not to test out the whole system until we had found a way to better secure the metal tin.

Plan for the next week:

Design and 3D Print a stand for the metal tin.

27/7-2/8, Week 12

We designed a 3D-printed stand for the CPU cooler to secure it to the metal tin and Peltier.

Semester begins

11/8-17/8, Week 1

Early in the week, we tested the entire set-up again without the code for now to see if all our components worked together.

We also realised that the water tubes were very rigid and we could not place the CPU cooler set-up above the container with the pump. So we decided to keep it as two separate components.

Later in the week, we met again to test a few things. We tested out a new Arduino code which we had developed. One issue was that the CPU cooler fan was not turning on when being activated. So we stopped the testing to prevent the Peltier from overheating.

Additionally, the pouch was leaking again and we identified that the pouch was leaking through the edges. So we decided to try to seal the tubes into a new pouch in a different orientation to avoid cutting through the edges.

Plan for next week:

Test out the new pouch and troubleshoot the Arduino code.

18/8-24/8, Week 2

We went to the lab again to troubleshoot the Arduino code and it works!

We tested the new pouch and it managed to remain largely leak-proof (it leaked a bit, but not as much as before). We also realised that our pump was too powerful and had to decrease the power supplied to it.

Plan for next week:

Amend the current circuit set-up for the pump and reseal the pouch again.

25/8-31/8, Week 3

The semester is starting to get busy for us as we are starting our research attachments. Our new MOSFET unit has not arrived yet so we did not manage to set up the wiring for the water pump this week. However, we took this time to work on the wireless control system as Dr Ho mentioned that it could be used for our demonstration. We have explored several methods and decided to connect the system to our mobile phones with Bluetooth and build a website as the user interface.

Plan for next week:

Code the website to control the system remotely. Test the new wiring set-up using updated Arduino codes.

1/9-7/9, Week 4

All our components ordered online have arrived so we went to the lab again to test out the new setup.

Firstly, our new pouch has finally survived the test and remains unleaked throughout! Woohoo!

Also, we realised that the water circulation is not working ideally. The water input to the pouch powered by the water pump is at a much greater rate than the water outlet which is mainly driven by the difference in water pressure. However, the pouch is expandable and thus it is crucial to regulate the pressure to control the water flow.

The TA suggested that we try swapping the position of the water pump to the water outlet end. However, this method failed because there was no constant pressure difference in our circulation system. After some attempts to adjust the voltage of the water pump, we found 4.4V to be the optimal voltage where the water flow is consistent.

Another problem was that our setup involved a lot of components connected by messy wires, which may cause electrical hazards and make our job difficult when we try to check the connection between the various components.

To resolve the issue, we are going to combine the three MOSFETs into two and redesign the circuit diagram to optimise the wiring.

Plan for next week:
Redraw the circuit diagram, update the Arduino code accordingly, and test the wireless control system.

8/9-14/9, Week 5

We reconnected all the components and tested the new code on the Arduino IDE, and everything was working fine.

The Bluetooth transceiver module that we are using for our wireless control system, on the other hand, is incompatible with the Arduino IoT webpage and the Blynk App, hence we purchased a WiFi module instead.

Plan for next week:
Connect the ESP8266 WiFi module with the Arduino IoT webpage, establish communication between ESP8266 and Arduino Uno R3, and control the set-up with Arduino IoT.

15/9-21/9, Week 6

We faced difficulties in connecting the ESP8266 with Arduino IoT, even after changing it out for ESP32D (a newer module) as the TA suggested, there was still no success. Therefore, we could not test the code with Arduino IoT.

With recess week around the corner, we have decided to focus on finalising the whole set-up, hence the tests for our website/App have been put on hold.

The metal tin was insulated with styrofoam sheets.

Plan for next week:
Secure the pouch to the pillow, secure the Peltier to the CPU cooler using thermal gel, and test out the finalised prototype.

22/9-28/9, Week 7

We met up to test our finalised prototype, all is good to go.

Plan for next week:
Prepare for final presentation