Category: Joshna’s Weekly Status Reports

Accomplishments

This week I worked on making the presentation and delivering it for class. It was busy week so I had to use a bit of slack time. I did order some parts, which will get here soon. I also started adding components and creating a schematic for the PCB. I didn’t have as much time as I wanted to, so the schematic is very bare bones.

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

I’m still right on schedule. I knew at the start of the course this would be a busy week, and so I intentionally spread the next deadline I have for myself a bit to be during fall break.

• What deliverables do you hope to complete in the next week?
• I need to finish ordering things, its taking longer than expected to source mechanical parts cost effectively because a lot of the parts I’m finding have bad ratings. There are some parts we will have to pay a premium for. As a result, I will beed to modify x/y gantry system to accommodate any changes in the parts we actually source.
• I also want to finish designing the PCB because need to send it out ASAP in order for it to arrive in time for the demo.

What did you personally accomplish this week on the project?

I created a CAD model of the x/y gantry, which honestly was quite a process because I had to convince myself the hard way CAD’ing our design from scratch was actually better than modifying a 3D printer.

Last Saturday I opened up Solidworks in the lab at Ansys and started downloading mechanical pieces to create the x/y gantry, and I noticed that the McMaster Carr linear rail and bearings were quiet expensive. I figured there was a cheaper way to source the mechanical components in the machine.  I looked on Amazon and I found a 135$ 3D printer. I figured that and a ramps board would be a quick way to get to MVP. We were advised against pursuing this route.

Here are some screenshots of the CAD.

This a general idea of what the internals workings of our embosser. We will have a way to feed paper using a driven tread that keeps tension with an idler tread. The treads will be positioned such that the paper is touching the tips of the solenoids. We will be adding screws to the solenoids so just the tip will likely be fine. There will be another linear rail with another tread on the other side of the solenoid.

This is the x gantry. The x gantry will be driven by a lead screw because lead screws don’t stretch unlike pulley based systems.

Here is the y feed system in isolation.

We were advised against doing an X/Y coupled system.

Is your progress on schedule or behind? 

We are right on time, we just need to order parts soon so we can begin testing this.

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

I want to order the parts for the x gantry system this week so I can begin manufacturing and making sure the parts fit together and reiterating as needed.

Our team overall have been using classes such as 18220 as well as more advanced megatronics and device science classes my teammates have taken to develop the embossing and communication design. The software design is inspired by webhacking learned in 18330, wrappers and database/cache organization learned in 18213, and testing/verification skills learned in 18240/18341. While the actual algorithms aren’t molded around an existing algorithm, the analytical skills and practice of coming up with our own stems from all the classes we have taken at Carnegie Mellon but for me, especially 15122 and 18213.

At the beginning of this week, I created a github (https://github.com/joshna-ii/digibraille) to help keep track of my progress and allow my teammates to work with my code, especially for when Zeynep develops the frontend further. I spent quite a bit of time later in the week working on the ReadMe and making it as easy to understand and use even in these early stages in order to set a precedent.

The main frontend file is called webapp.py, and I spent the first half of the week using the Flask library in order to create a website which is currently hosted locally (127.0.0.1:5000) when you run the python program. This is an example output and handler:

In general, I have been able to handle the different types of non edge-case inputs and a couple edge case inputs (non-input. poor web link formation) from the website post stage to the string that needs to be translated.

Based on the html user input, I had the webapp.py frontend handling file call the run_backend function in main_backend.py. This next file’s brings together the different parts of the backend: rpi_handler.py, translation.py, websearch.py, and soon a database file.

Websearch.py does the actual webscraping and queries depending on if main_backend.py received a link or a product name. I have a function called google which returns the first link for a google search given the keywords.

I have also created a function that handles direct links that are inputted as well as a function that finds matching keywords in all the pages of websites such as directionsforme and backoftheboxrecipes using the requests library and beautiful library.

The bulk of the execution code (outlined functions are still connected clearly everywhere) for the third function is currently in my temp_code.py file because I have been doing some unit tests, edge cases, and one-off tests. While I have been able to improve efficiency by tenfold by only accessing certain attributes of the webpages, it is still way too slow so my plan is to spend the beginning of next week transferring data from these websites to an internal database by modifying the function I created this week in order to make this process faster. If sufficient results have not been found with the internal database, main_backend.py will use the google function I worked on earlier and mentioned above and webscrape directions off of that.

I also spent a couple hours learning how to work with the raspberry pi yesterday after receiving it.

I am having trouble communicating with it as my laptop does not seem to recognize the device when I ping localhost so I am getting an ethernet cable today to try it that way and if that doesn’t work, I will go to campus and try to connect it to one of those computers. I am spending today working on rpi_handler.py in order to host the basic website through that and get the basic framework down for how the python files will communicate signals on location and movement of solenoids+motors to the raspberry pi post translation through the gpio pins.

I have also spent time this week working on the design presentation for next week including creating block diagrams, scheduling, designing algorithms, figuring out interactions between components, and calculating quantitative expectations.

While I did not achieve the reach goal I set last week of getting 50% of the webscraping done due to this method turning out to be innefficient, I am still on track with our expected schedule with the webscraping, website, and integration files so I do not have to reorganize the schedule.  My goal for this week is to get the basic rpi – python script communication down, get 50% of the webscraping done with databases and creating said database, and start the braille translations while making a more detailed schedule based on the different rules braille follows. I plan to translate the current string output I create to a list of a set of 6 signals with some of the more general braille rules after learning Braille even better myself as a person since there isn’t a 1:1 mapping between the english alphabet and braille characters.

We spent most of this week developing our design and practicing for the presentations. We honed down our use case to specifically help visually impaired people by allowing them to either enter notes and print that on our website or enter a product and print the instructions for using that product. We also figured out what tools we want to use and how to divide everything up. Our current plan is to use Python and HTML to develop the frontend, use Python for webscraping and databases and communicating to hardware, host our webpage on a CMU server, and use gcode instructions to control a RAMP board which controls the solenoids and the motors that move the solenoid system across the page.

I also started working on the webscraping portion since we were told to work from the most difficult part outwards. I have tried working with many Python libraries including googlesearch, requests, urllib, mechanize, and more in order to figure out how to make google queries in the easiest way. After a lot of debugging, I am only able to get the first google result. There isn’t much information about the generator object type for webpages and it appears like I am getting 0-1 results when I shouldn’t be. I also received a lot of errors with actually accessing a website to begin with but I believe that is because I am accessing the browser directly through code and so google treats me like a bot. I am looking into using other websites/browsers for searching.

I am able to get the first website from google now but I began to wonder what I would do if I were to get more than one result because there isn’t a standard to figure out what would be the best website for each product. I have started implementing using a website like directionsforme that already has lots of product compiled like a database while also using the first google search for any product that is not listed on this website. The webscraping should be easier for products on directionsforme because it is relatively standard so I am focusing right now on the best method for finding the information I want to scrape from each of the websites google returns. I am also considering whether or not I should have a feature that reads back the result and confirms with the user if that is what they want to be printed.

Another thing I have started to think about is how we will send instructions to the embosser. Since we are trying to make this as accessible as possible, we have to make sure that the embosser is an easy set up and that the website can actually send the instructions to the embosser. Wireless printers work by connecting to the same WiFi network as the device that will be printing. There is a RAMPS WiFi adapter so we might think about using that so we can continue with this design. I don’t have experience using gcode but Becky does so I did more research in how it works and it is common to send gcode wirelessly to 3D printers by connecting both to WiFi by using a WiFi SD card. I still have a lot more research to do on the interfacing between the webpage and the gcode output across WiFi.

Since we are still at the beginning of our project, we are on track. My goal is to make the webscraping algorithm work for 50% of the top product searches by the end of this next week. I also plan to get some of the basic html framewok up and running because neither Zeynep or I have much experience with actually building a website so it would be better to start earlier so we have more time to resolve issues. Lastly, our team also needs to make sure we understand the communication between our parts both because that will help define each of our “inputs” and “outputs” but also because it might require us to buy additional components.

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