Module 2 Activity Research

Weekly Activity Template

Emily Revell

Project 2

Module 2

In this module, we focused on research and testing to advance our understanding of physical computing concepts and to inform the development of our prototype. In my group of four we decided to split up into two teams one team would focus on the physical development of our prototype while the other focused on the technical aspects. I was on the technical team with Abby and our main focus this module was to research and test the functionality of the two sensors we wanted to implement into our prototype.

Workshop 1 Geurilla Prototyping I: Phone Stand

During week 7 we were given the task to create a geurilla prototype of an iPhone stand using one of the two tutorials provided in class. After completing the tutorial, we were also then asked to improve and make our own iteration of the stand based on how we could improve the original. This is an image of the final phone stand created by following the tutorial by Maker Brain. <a href='https://www.youtube.com/watch?v=3LgJ7QjEKZs' target='_blank'><p>Link to Initial Tutorial Video</p></a>

This is the dissassembled geometric net of the initial phone stand created by following the tutorial by Maker Brain. The tutorial teaches you how to create a phone stand without the use of glue or tape and instead uses folding/interlocking techniques to help hold the stand together.

The next step of the activity was to iterate and improve upon the initial design of the phone stand. On the right is the phone stand made by the tutorial and on the left is the improved iteration of the stand.

This is an image of the back of both phone stands. The main iterations we made improved on the stability and adjustability of the stand. First we included a lip at the front of the stand to help support the phone in place. Next, we added arms and extra panels to the back of the stand to allow the user to adjust their viewing angle.

This is an image of the new iteration of the phone stand in action holding my phone.

Workshop 2 Geurilla Prototyping II: Finding the Perfect Test Subject

At this point of the project we already had a general idea and direction of what we wanted our prototype to look like. Thus, our next step was to gather test subjects and materials to begin testing as well as the creation of our geurilla prototype. Additionally, during this stage of the project both Lucy and Nicole prioirtized investigating and testing the physical aspects of the prototype. This is an image of the three stuffed animals we used as our test subjects.

This is an image of Pongo, one of our three test subjects. Although cute, Pongo was the least liked by the test population due to his small size and lack of 'huggability'.

This is an image of Mario, another of our three test subjects. Overall, Mario was the second most liked test subject due to his medium size, familiar bear form, and cute outfit. In general, the thing people didn't like the most about Mario was the texture of his fur as many felt that it felt 'ratty' or scratchy.

This is an image of Miffy, the last of our three test subjects. Miffy was by far the most liked by the test population due to her huggable size and soft texture. Additionally, many test subjects liked to play with Miffy's ears which helped us determine a possible interaction method for our final prototype.

Although, I was mostly on the technical side of the project, we all ideated and worked together to ensure the direction of the prototype. Therefore, most of the second guerilla prototype workshop involved finding the right stuffed animal for our prototype.

Activity 1: Testing the Pulse Sensor

Many sketches that we explored for measuring heart rate using the pulse sensor utilized similar wiring. They would put the white wire (signal) into pin 0, the - black wire into ground, and the + red wire 3 volt (power) pin to activate the sensor.

The HW-827 heart rate sensor works by shining a green light onto a thin part of your body, such as a fingertip or earlobe. This light then travels through your skin where some light is absorbed by your blood and the rest is reflected back. The pulse sensor utilizes a part called a photodetector which measures how much light is bounced back. The process is called photoplethysmography (PPG) which means it measures the changes in blood volume using light (Last Minute Engineers).

This is an example of us testing one of the few skethces we found to see if both our wiring and code was correcnt.

During our testing we also tried to use the serial plotter to see if it was possible to visualize our data (heart rate) to further verify if our code was working properly. In the graph above, the signals seem to be irregular with inconsistencies in the peaaks and troughs. This tells us that there might be issues with our code, sensors, or both. <a href='https://lastminuteengineers.com/pulse-sensor-arduino-tutorial/' target='_blank'><p>Link to Tutorial for serial plotter by Last Minute Engineers.</p></a>

Unfortunatley, we were unable to get the pulse sensor to consistently read the heart rate data. Some issues we encountered included the BPM would always skyrocket to 220 and above (even after correcting baud rate & pin #), it would occasinally take a long time to calibrate, and even playing eith the threshold values didn't seem to help. After spending a lot of time trying to debug both our wiring and code, we decided to move forward so that we could at least have one sensor working for project 2.

Activity 2: Testing the Grove Temperature Sensor

This is an image of the grove temperature sensor properly connected to the arduino at the very beginning of our testing.

This first sketch was provided in class during week 3 during the arduino, protopie, and the temperature/humidity sensor using the kit. We ended up writing a different code as wwe were not ready to integrate with protopie and we did not want to include humidity (the Grove Temperature sesnor we used also does not have a humidity sensor on it).

In the second sketch we found online the temperature displayed in the serial monitor was not reading correctly. Even after changing the baud rate to 9600 (as it was set to 115200) the temperature still was not reading correctly. <a href='https://www.youtube.com/watch?v=2mne6ZVLhhA' target='_blank'><p>Link to Tutorial for Arduino Temperature Sensors by Science Fun.</p></a>

Lastly, wew found this third sketch on the manufacurers official website for our specific grove temperature sensor V1.2 by Seeed Studio. The only changes we made was the addition of code to show both celsius and farenheit. Additionally, we also increased the delay value so that the data was more legible on the serial monitor. <a href='https://wiki.seeedstudio.com/Grove-Temperature_Sensor_V1.2/' target='_blank'><p>Link to documentation by Seeed Studio.</p></a>

This is an image of our final testing setup once we finally got the temperature sensor to read and work as intended. Overall, the temperature sensor was much less sensitive to wiring and code issues in comparison to the pulse sensor.

Additional Research & Workshops

This is an image of the wiring for the capacitive touch workshop that was hosted in class.

This is an image of me testing how the capacitive touch sesnor works. When I touched the exposed wire the 0 would change to 1 in the serial monitor.

This is an image taken of the serial monitor while testing the capacitive touch sensor. One of our biggest take aways was when Steve talked about the struct function and how it'll be used to help integrate your code with protopie.

After finding the documentation for our grove temperature sensor we were curious about what other things we could find by Seeed Studio. We found an introduction to the Grove ecosystem, which is something we could explore further in project 3.

When developing and testing how to work the our specfic pulse sensor Last Minute Engineers had very comprehensive documentation and tutorials about the sensor. Between them and the library you can find on arduino IDE they helped us the most during development.

Project 2

Project 2 Prototype

This was our final prototype for project 2. Although we were unable to get both sensors working by the end of project 2, we were at least able to successfully integrate the temperature sensor with our chosen stuffed animal, Miffy. By the end of proejct 2 we at least wanted part of our prototype to be functional for user testing and feedback. To interact with Miffy you hold onto the heart on her ear so the sensor can begin to measure your body heat and display it in the serial monitor. Finally, moving forward our next steps would be to legnthen the wires for easy hiding, test more sensors for better integration with the stuffed animal, and finally integrate the code with protopie for a more seemless experience.

This is an image of our final prototype for project 2. So far we were able to at least integrate the temperature sensor with our chosen test subject, Miffy the cute brown bunny.