Coffee Maker Alarm

This is a project which I and my classmates had finished in a course focusing on practical implementation for mechatronics and system design, and is a sequel of the previous Aroma Alarm Clock project. We designed an Android app-controllable alarm clock which can heat up objects such as a water-filled container, and intend to further improve it for making coffee, so that one can enjoy a fresh cup of coffee in the morning after awakening. Similar to the previous one, I worked as the engineer in our group, and designed and constructed the hardware system.

System Framework

Fig. 1 shows the overall system architecture, which several electronic components (e.g. clock module, LCD display…) are controlled by a microcontroller that can communicate with a mobile application using a Bluetooth module. The alarm clock can be controlled either using its own hardware input (buttons) or using the mobile app. Simply put, the system has same the functions as a typical alarm clock, but has two additional features:

1. Temperature controllable heater.
2. Bluetooth communication.

Figure 1. System architecture for the coffee maker alarm.


Arduino Uno, DS1302 chip, HC-06 and LCD1602 are used respectively for the microcontroller, real-time clock module, Bluetooth module and LCD display module. Being an end-semester project in class, the components are simply connected using a breadboard. All the hardware components except the heater are packed using patterned cardboard in a simply looking fashion (Fig. 2).

Figure 2. Hardware appearance of the coffee maker alarm.

A ceramic heater plate and temperature sensor are integrated for realizing temperature controlling (Fig. 3), and are connected out from the main hardware. The total cost for all the components is 1,741 NTD (≅ 60 USD).

Figure 3. Heater and temperature sensor.


App Inventor 2 is used as the platform for creating the Android app for controlling the hardware. Fig. 4 displays the designing interface for the mobile app using the platform.

Figure 4. Design interface using App Inventor 2.

The coding section for this platform is very unique and easy to get started. It implements a block-based programming method which developers can create procedure by dragging pre-defined blocks together to for performing a certain function. Developers with no programming background can use this kind of environment for creating mobile apps. Fig. 5 shows a gallery containing the complete code for the alarm clock controlling app.

Figure 5. Gallery of block codes for the alarm clock app.

Here’s a video demonstration for using this system:

After finishing this project, I acquired important skills for system design and mechatronics integration. This enabled me to create more interesting and sophisticated projects such as the Automated Microfluidic Controlling Platform, Remote Commandable Self-Driving Toy Car and Real-time Impedance Detection Systems.

Aroma Alarm Clock

As an old saying goes, “An hour in the morning is worth two in the evening”. What we encounter and conceive during this period is largely intertwined with our whole day. However, what is the most important thing that we encounter in the morning? It is about waking up. Nowadays, we wake up by the noisy, buzzing sound of an alarm. How would it be like if we could wake up by a scent, a fragrance, wiping away the unsatisfactory memories of the past? What can be changed to fulfill a better awakening?

An aroma alarm clock should fill in the answer. When I was a junior, I enrolled in a program called “NTU Creativity and Entrepreneurship Program” (NTUCEP). In this program, students with similar ideas form groups and learn about entrepreneurship by practice. After a couple days of brainstorming, our group came up with the concept about developing an alarm clock that can wake people up using scent packs. Apart from being awakened by a loud ringing sound of an alarm, fragrances (as we had proposed) have a milder, progressive effect for waking people up. We named our product “Sensio”, a Latin noun of the meaning “thought”.

Market Survey

In order to verify the market demand of this proposal, we devised a questionnaire for investigating the views and habits of people about waking up, which 1320 valid responses were collected. A score of 0 ~ 7 is used to quantify the “discomfort level” for waking up, in which a level of 0 ~ 3 is regarded as painless, and 4 ~ 7 as painful. Fig. 1 shows the discomfort level distribution of all the samples, and Fig. 2 shows the distributions by occupation. It can be seen that regardless of identity, the majority of people feel painful when waking up (students: 71%, office worker: 62%, other: 51%, overall: 68%). Moreover, we analyzed their habits of lying in bed after awakening. Fig. 3 shows the proportion and durations for lying in bed. Accordingly, over 44% of people lie in bed for over 15 minutes, and the average duration is 15.07 minutes. Theoretically, this means if a product could help lower one’s discomfort level of waking up, and reduce the duration of lying in bed after awakening, he could approximately increase 3.8 days/year of effective time. Not only having a favorable morning, but also enhancing his work efficiency.

Figure 1. Discomfort level distribution of waking up.

Figure 2. Number of people vs discomfort level by occupation.

Figure 3. Duration of lying in bed after awakening.

From the above analysis, we became confident about the large market demand for a better quality of getting up. For me, being the leading engineer role in our group of six meant turning ideas into reality. This had been a difficult period but a time of inspiration and excitement. I put into practice what I had learned within the past few years for developing a system, a hardware that can really be used as a product.

Sensio v0.1

I developed two preliminary versions of the hardware, with the 1st version using Arduino as the CPU (Sensio v0.1) (Fig. 4). In this version, an Arduino chip, a time clock module (DS1302), a shift register (74HC595N), relays, button switches, LED displays, a buzzer, a fan and a potentiometer are used for the alarm clock (Fig. 5). 10 different themes are written inside the system and a few simple features are integrated within (Fig. 6 details every mode of the alarm clock and the corresponding function of the buttons). This version serves as the proof-of-concept version for making an aroma alarm clock. Although being simple and somewhat rough, it demonstrated to my team and our professors a solid proof and feasibility of our objective.

[Source code for Sensio v0.1]

Figure 4. Photograph of Sensio v0.1.

Figure 5. Hardware architecture of Sensio v0.1.

Figure 6. Alarm modes and button function for Sensio v0.1.

During this period, we earned 40,000NTD in a fundraising event in our program, and won the Best Potential Award in the 14th NTU innovation competition. Fig. 7 shows the poster we had used in the competition. During that period, we had great enthusiasm and motivation, and dreamed that one day our product would become on-sale and we could establish a real listed company of our own. We entered the NTU garage, which is an incubator for startups that are closely linked to NTU.

Figure 7. Poster of product Sensio for the NTU innovation competition.

Sensio v0.2

The second version Sensio v0.2 was created during my second semester as a junior. This time, an IC chip (ATMEGA328P) is used as the CPU rather than Arduino in order to lower the cost of the system and decrease its volume. Moreover, a PCB layout for fixing electronic parts on a solid panel is used. Fig. 8 illustrates the structural model of Sensio v0.2, Fig. 9 shows a photograph of the integrated electric components and its corresponding PCB layout schematic, and Fig. 10 shows photographs of the laser-cut 3D outer case.

[Source code for Sensio v0.2]

Figure 8. Structural model of Sensio v0.2.

Figure 9. Electronic component-integrated PCB board of Sensio v0.2 and its corresponding layout schematic.

Figure 10. Outer case (blue) and scent pack holder (orange) of Sensio v0.2.

We were thrilled after these accomplishments, since never had a team of the same period achieved such a high level of completeness, especially when concerning the integrity of hardware and software. These remarkable things happen so quickly, so fleeting for us to catch up with. The truth is, we are still so far from success, since we were still students back then. Reality pulled us back, and we started asked ourselves: are we ready to give up some things and dedicate ourselves to entrepreneurship? Our dream product, the aroma alarm clock, had once seemed so close, yet had never seemed so far.

Although in the end, the functional aroma alarm clock wasn’t successfully made, what I’ve learned during this event is unprecedented compared with my past experience, not only techniques for hardware and software development, but also important philosophies for entrepreneurship. This project inspired me to a great extent, and enabled me for creating future hardware-related projects (e.g. Automated Microfluidic Controlling Platform, Real-time Impedance Detection Systems, Surface Plasmon Resonance Platform) in my own field of research.

Figure 11. Photograph of our team and professor.

Logic Circuit Control for Number Display

Most people believe, including me, that programming is a powerful technique, and a lot of things in everyday life are realized by programming. However, being taken away this skill, what can still be achieved?

In this project, a logic circuit with complex functionality is built using only simple IC chips and circuitry. A 7-segment LED displays numeral from 0 to 9 with adjustable frequency using a potentiometer, and the number can be reset anytime to 0 by pressing a reset button. For programmers utilizing a simple development board such as Arduino, this seems like a piece of cake. However, it requires a certain degree of knowledge for digital circuit and IC chip control in order to accomplish it without coding.

Here, two simple IC chips are used: a 4024 counter and a 4511 BCD to 7-segment converter. An oscillator circuit with square wave output and potentiometer-controllable frequency is constructed, and the signal is fed into the 4024 counter, which outputs bitwise data to the 4511 converter, and eventually sends to the 7-segment display. A latch circuit and button is connected to the reset input of the 4024 counter for adding the reset function.

I was fascinated by the wide applicability of digital circuits, which can achieve low-cost and stable hardware features such as this project.

Here’s a video demonstration of this project (note that the Arduino on the left is just for power supply):