Category: Zeynep’s Status Reports

This week, I spent most of my time debugging the Arduino code to successfully be able to emboss braille up to specs, adding other hardware components to the device, and also spent a significant amount of time finalizing the full pipeline with Joshna. My primary accomplishments for this week include setting up the code to control the LDR and LED, finalizing the code for the solenoid and motor control to enable embossing, creating the rigid surface for the solenoids to emboss against, setting up a speaker to provide cues to the user, securing the tension of the solenoids, and working with Joshna to finalize the full pipeline.

In addition to work on the hardware components, I created both the poster for the final demo and the slide deck for the final presentation, and practiced for my presentation.

To set up the code to control the LDR, I worked with Becky to determine a threshold for which the photoresistor was sensitive to light. Then I used that threshold and calculated the specific distance the roller should move to place the paper in the proper location.

For the solenoid and motor code, I spent a considerable amount of time testing different distances between the solenoids and the two motors to create the optimal braille output. This took some more time than expected because there were issues with power supplies and motor drivers.

I also worked to finalized some of the variables for the tension of the system. I contributed to creating the rigid surface and securing the embossing styluses attached to the solenoids. I also incorporated a speaker to provide cues to the user.

Finally, I worked with Joshna on Saturday to test the full pipeline with integration, ensuring the RPi was properly sending signals to the Arduino to emboss the paper.

 

This week, I focused on testing the solenoid and stepper motors of the physical embosser, doing user testing, and refining the web-app. I refined the web-app a bit more to ensure that everything was as clear as possible before user testing, but I spent a majority of my week focusing on debugging the Arduino code and testing the braille outputs of the solenoids and stepper motors combined. I have attached a video that shows an example of the work I have been doing with the solenoids and stepper motors. I have also helped with the assembly of the embosser. We also had a user testing session on Friday where we had users test the web app and tactile experience with the embosser.

This week I worked on refining the web-app and hosting it on a domain, debugging the web-app to solenoid pipeline, and starting the arduino code for the stepper motors.

Joshna and I visited the LAMP Library on Tuesday to get some user feedback for the webapp. Overall, the participants were happy with the design/layout of the web-app and were able to navigate it with ease. They suggested some small tweaks which I am currently implementing. I also worked with Joshna to debug some issues in the web-app to solenoid pipeline when communicating with the arduino using the RPi. We had some issues with how the signals were being sent to the arduino and we worked to debug that. We now have a fully working webapp to solenoid pipeline. Our next step is include the stepper motors into this pipeline. I have begun writing the arduino code for the stepper motors. My goal is to have this complete before Thanksgiving to give to Becky to work with for the electromechanical system.

ABET #6 says … An ability to develop and conduct appropriate experimentation, analyze and interpret data, and use engineering judgment to draw conclusions

Now that you are entering into the verification and validation phase of your project, provide a comprehensive update on what tests you have run or are planning to run.  In particular, how will you analyze the anticipated measured results to verify your contribution to the project meets the engineering design requirements or the use case requirements? 

My individual components included designing the embosser system with solenoids and creating the web-app. The use-case requirements that my components cover include fast delivery of braille, accuracy of embossing, and providing an accessible interface. Our speed requirement was driven by the time it takes a user to manually emboss braille using a braille writing slate. Based on user interviews prior to starting our project, we determined that it takes 15 minutes to write a full page of braille on a braille writing slate and we required the braille printing process of our device to take at most 10 minutes. To design for this, we required our solenoids actuated at < .5s. We also required 100% readability of the braille. This will be realized through providing proper force from the solenoids to emboss, ensuring proper spacing between the solenoids, and that our embossed braille is to specifications. As for our UI, we required our web-app to be able to interface with existing accessibility features on phones and that it takes no more than 1 second to display results. We required our user to be able to acquaint themselves with the web-app and device < 10 minutes through an easy to use interface with feedback to the user. 

Testing for speed: We communicate with the solenoids by sending a digital high to an individual solenoid, delaying by x seconds, and then sending a digital low. I have been testing for the threshold of delay by gradually decreasing the amount of delay i can have without damaging the circuit. Once we establish the tension system, I will repeat this process of gradually decreasing the amount of delay we can have between the digital high and low that will still allow the solenoids to emboss. I also plan to test 10-20 inputs such as notes or products to see if the embosser is able to print these at the proper speed.

Testing for force/embossing capability: The force provided by the solenoids dictates our embossing capabilities. Our solenoids can be powered with up to 12 V. I aim to use as little power as possible. Once we have the tension system in place, I will test the solenoid’s ability to emboss paper in voltage increments of .5 V up to 12 V starting at 4 V. I also plan to test 10-20 inputs such as notes or products to see if the embosser is able to print these.

Testing Solenoid Control Circuit: We have just sent out our PCBs, but I have tested the solenoid’s control circuit by making it on a breadboarding and using the serial monitor in arduino. I mapped every combination of the four solenoids to a set of values in a truth table and have tested the circuits ability to withstand embossing in different combinations starting at 10 seconds and worked up to 10 minutes, which is our maximum embossing time. This is representative of how we will be communicating with the arduino using the RPi.

Testing for specifications: Once we have our electromechanical embosser system in place, I will measure the distances between braille characters to make sure they are to specification. We will also have user testing to ensure that the braille is readable. I also have printed braille from a state-of the art printer. I will compare our braille with this braille output to see if the size is similar. I also plan to test 10-20 inputs such as notes or products to see if the embosser is able to print these to specification.

User Testing: I have been testing the web-app using the text-to-speech capability on my phone. This is to ensure the button spacing is enough for the text-to-speech to discriminate based on touch. I also want to ensure that the text-to-speech isn’t overwhelmed by the amount of text I am displaying on the screen and is able to communicate the information clearly. This coming week, we are going to be having a user testing session at LAMP Pittsburgh with blind and partially blind users. This test will be a great way to gauge the usability of our app and will inform any adjustments I may need to make towards our final demo.

Weekly Accomplishments: 

This week, I focused on finalizing the web-app to ensure that it was easy to use for completely blind users and clear for partially blind users. This process included ensuring proper spacing between all of the buttons, testing our web-app’s features using text-to-speech to assess  the clarity of our buttons, ensuring large text, and limiting the amount of text on a page while making sure our users understand the flow of our site. I have also publicly hosted our web-app so it is more accessible to users (it is not ideal for a blind user to have to type the name of the local host). After talking to Joshna about how the braille cells will be mapped to the solenoids to emboss, I realized we needed to make slight modifications to our solenoid encasings and x/y gantry cart to ensure proper spacing between each embosser head (4 braille cells apart in x and y direction). I modified these parts in CAD and sent them to be 3D printed again.

In the coming weeks, I will be working with Joshna on integrating the software and hardware through the RPi and arduino, and working with Becky to assemble the electromechanical embosser. I am also working on establishing unique user sessions to ensure privacy of the user’s data.

 

This week, I focused on finishing the web-app and integrating it with the back-end, fabricating solenoid enclosures, and testing the solenoid control circuit for demo. Since last week, I added the ability to display the product information on the web-app based on information return from the back-end. I also had a few bugs with my buttons and page refreshes  that I fixed. I received my first fabricated enclosure for the solenoids, but it had a few issues so I adjusted my enclosure design and sent it out to be printed again. Because we switched from controlling the hardware with a RPi to controlling with an arduino via uart, I had did testing on the solenoid control circuit with an arduino and sent it signals over the serial monitor. Each solenoid command will correspond to an embossed braille character. I am currently testing the speed we can run the solenoids at.

This week, I worked on the ethics assignment and discussion, implementation of the web-app, and preparing the solenoid circuit for testing/integration. For the ethics assignment, I read the two given papers and completed my written assignment. I also engaged in a group discussion about the ethical considerations of our project. Some points that were raised in our discussion include electrical safety and ensuring that proper instructions are printed. I also continued to work on the implementation of the web-app. I am working on setting up the product search functionality on our user interface. I have added the ability to pull results from the back-end and display them, included buttons to scroll between pages, and wrote code to fill the web-app with content from the back-end. My goal for next week is to tweak small bugs in the UI, such as the product name not being displayed on the second page and incorporate code for parsing and properly formatting the product text file to display the information. My stretch goals will be to have the basic framework of the website complete by the end of next week to be able to begin debugging it with Apple’s accessibility debugger tool.

(page two after clicking next button)

(after clicking product place holder for displaying product info/recipe)

I received the solenoids and the grub screws I plan to use as the embossing stylus. I tweaked the design for the solenoid encasing in CAD now that I have the solenoids I am going to use. I also built the control circuit for RPI testing using LEDslater this week as we wait for the PCB to arrive.

 

ABET #7 says: An ability to acquire and apply new knowledge as needed, using appropriate learning strategies

As you’ve now established a set of sub-systems necessary to implement your project, what new tools are you looking into learning so you are able to accomplish your planned tasks?

I have been learning a lot about how to use CSS, Javascript, and HTML to develop the web-app. I have minimal front-end experience, so I have been spending a lot of time reading documentation and learning how to use these to best implement or web-app to fit our user needs. I have also been learning how to use CAD software to iterate on our design to ensure our building/integration process goes as smoothly as possible. I am also familiarizing myself more with using a RPi with the solenoids.

What did you personally accomplish this week on the project? Give files or
photos that demonstrate your progress. Prove to the reader that you put sufficient effort into the project over the course of the week (12+ hours).

These last two weeks, I focused on the design review document, and working on the web-app.

For the design review document, I helped write the introduction, use-case requirements, architecture, design requirements, trade studies, implementation, and tests. I also created some of the figures included in the document, such as the system block diagram or the solenoid mechanism figure.

I also incorporated some feedback and changes into our overall design for the electromechanical embossing system with the addition of two more solenoids into our design. This involved recalculating our timing, and re-adjusting our solenoid system design. Once these changes were in place, I also began working on the PCB design. I added the components for the solenoid system. Becky will be in charge of other parts of the PCB.

After submitting the design review, I continued working on our web-app. We are aiming to start user studies on the front-end next week, so my goal is to have the basic framework done by then. I have attached screenshots of the pages I have implemented, which will all communicate with and display results from our back-end once the database is complete.

Progress and Deliverables

This week did have a lot of slack for me because of fall break, but I am planning on putting in extra hours to finish up the front-end before user-studies. I have also placed my orders for components and will finish up PCB design for the solenoid system, and begin building with my team members leading up to the interim demo.

Accomplishments

This week, I primarily focused on completing the design presentation, working on the design review document, ordering parts/refining our bill of materials, and I began work on the web app. I spent time at the beginning of the week refining our design presentation by creating informative block diagrams and figures and cleaning up the slides.

I also began work on the design review document and transferring information from our design presentation into the document. I also refined the BOM and decided on some of the specific parts I would need for the solenoid system. I ordered the solenoids and I will begin ordering more components (such as screws, diodes, mosfets) later in the week.

I also began working on our web-app. This is my first time using Flask and html, so I spent time reading through documentation and learning about how to use Flask. After I read through documentation and felt more acquainted with the framework, I began implementing our wireframe web-app design into the actual web-app. I am currently focusing on having the basic layout of the web-app complete. After that I will focus on specific design choices for its implementation based on accessibility documentation to make it most accessible to our users. My progress is a bit slow at the moment as I get more used to Flask and html, but currently I have created home page and two separate pages for each feature of our website. I have attached to example screenshots of my progress so far. The user input on this page will be sent to the back-end of our code.

Is your progress on schedule or behind? If you are behind, what actions will be taken to catch up to the project schedule?

My progress is a bit behind schedule at the moment. I have been out of town since Thursday, so I have not been able to devote as much time as I would like to working on the front-end. In addition, because I am out of town, I haven’t been able to work on my hardware component. In the next week, I will spend extra time to finish up the basic layout of the web-app so we can begin user testing, and work with Becky to design PCBs to send out during fall break. I also note that I emphasized finishing the solenoid circuit and encasing design, and testing prior to my weekend out of town so I would be ready to work on PCBs the following week.

What deliverables do you hope to complete in the next week?

In the next week, I hope to finish up and refine the basic layout of the web-app for user testing and finish up testing the solenoid system for PCB design by the end of the week. I will also complete the design review report, which I predict will take a good amount of my time this week.

 

This week, I primarily focused on designing the solenoid embossing system and working with Becky to see how it would fit within the larger x/y gantry printing system. I also incorporated the user’s feedback into my current wireframe. (digibraille_wireframe_updated).

Before beginning the design of the solenoid system, I spent a lot of time consolidating my research from the previous week to select the best solenoid for our use. I decided on using a DC 12 V solenoid with a screw insert on the iron core. This solenoid will be the best for our use case because it provides enough force to emboss the paper (20 N) and will allow for us to screw in the braille pin-head for embossing. After I decided on the solenoid type I was going to use, I was able to begin thinking about designing the circuit and how to control the solenoid. This process involved employing my knowledge from my device sciences concentration, primarily 18-220 and 18-300 . The primary issues with using solenoids are the power consumption and controlling the switching of power on and off through the solenoid. The switching problem was an easy fix through the incorporation of a flyback diode in parallel with the solenoid. I am currently using an NMOS to control the circuit.

I tested this circuit in the LT SPICE simulator to make sure it was acting as desired, and would not exceed power requirements. Based on the available datasheet for the solenoid,  I calculated its internal resistance and inductance and modeled it as a resistor and inductor in series for my simulation. I then ran simulations of this circuit on LT SPICE over a time window of 10 minutes (our predicted embossing time) to test the power consumption of the circuit. I fed in a randomized square wave to represent inputs from the RPi. Based on stimulations, this circuit appears to be stable and fits our needs. However, I may still make modifications as I continue to test.

I also began to prototype this circuit. I was able to test it using a waveform generator as displayed in the simulation and a DC power source. I hope to test it using the RPi in the coming week.

I also worked through the math for deciding how many solenoids to use and investigated the question of how the system will move (i.e. one cell at a time, one line at a time, one cell per solenoid). I calculated exact spacings between the solenoid and braille cells based on the American Society of Braille requirements and the size of the solenoid. Based on this, we decided the solenoids should move only in the x direction, embossing the braille line by line. I also calculated the time it would take for each number of solenoids to emboss based on the specific distances they need to be embossing within. Based on my results, I decided that two solenoids would be optimal, as the speed begins to plateau after two solenoids.

I also worked Becky this week on some of the design of the braille embossing system and x/y gantry. I designed an enclosure for the two solenoids in Fusion 360 that will fit into her x/y gantry design.

I also spent time working on the design proposal presentation — creating block diagrams, writing tests and requirements.

Is your progress on schedule or behind? If you are behind, what actions will be taken to catch up to the project schedule?

My progress is currently on schedule with the Gantt chart for the hardware components I have been assigned to. I am a bit behind schedule for the UI component of my role so I will devote the upcoming week to catch up on that. I aim to have the mock-up complete and some initial features implemented on the front end by the end of next week

What deliverables do you hope to complete in the next week?

In the next week, I will continue to test the solenoid circuit with the RPi. I will complete the mock-up for the front-end of the web-app and begin implementing features. I will also work on the design proposal document.