Digital Technology Summer Fellows 2021

Welcome to the week 6 update, where I started to connect the software and hardware components. While I much have rather been at the stage of calibrating how much the motor should turn given a specific unit measurement, much progress was still made. This week I started by creating a Python file that would allow me to test that the Raspberry Pi and stepper motor would communicate with each other effectively. I was able to get a file that asks for a number of steps so that the stepper motor would rotate. This was a success and did not take long to function. I also developed my Python file that deals with speech recognition. The code now asks the user for a command. I also had to brainstorm possible situations where the user might be missing information. Handling these situations is important because we want all the necessary information to be able to get a valid measurement. This was all possible because of my knowledge from developing the Alexa Skill earlier on in my project. During the progress of my Alexa skill, I was able to pick up on dealing with missing information and valid commands. One aspect I did implement was making sure that the user’s command has a valid wake phrase, so the speech recognition program knows to take action. Also implementing follow-up questions for the missing information. Even though I did not use the Alexa skill, I was still able to make the most of that learning.

During this software development, I did face some trouble with handling if the user command read the quantity number as a word or an actual number (Ex. one or 1). This was something I, later on, notice while testing. Luckily Python has so many libraries to access that I was able to find one called word2number that takes in a string and picks up on any number word to convert it into a number unit. Sometimes the speech recognition would pick up on the actual number unit, other times it needed the support of the word2number library.

The last thing I worked on for the software was implementing the text-to-speech attribute. Text-to-speech is the component that allows whatever text is written on the computer to be said out loud. This is a very common tool used among the visually impaired community, in order to get an assistant to read out loud what is on the screen. This is important to implement so that the user can get the voice assistant to have an almost natural conversation when there is missing information. I was able to find Google’s text-to-speech, however, I later found out that it is not available for use on Raspberry Pi. I spent many hours trying to find another replacement, but none were successful. I ended up taking a break from it and it will be one of the tasks to come back to over the weekend.

On the hardware side, more 3D printing occurred. After testing the stepper motor with random step values to turn the hardware components, I found that I had to reprint the spiral piece again but with the resin 3D printer. I had to reprint the spiral because it was rubbing a lot with the case inside. Also, the PLA 3D printer made extra material hang from one of the sides which makes substances like the rice more prone to get jammed. Below is an image of the PLA spirals vs the resin spirals. As you can see the resin spirals came out much smoother.

On the note of 3D printing, I also began to print other components to the hardware to clean up. I printed out a substitute to replace the plastic water bottle I was using as the hooper. I will let the following picture show you what I walked into the next day… you can imagine my reaction.

For now, I will continue to use the plastic water bottle as the hooper because I tried several times to print this part and every time, it had a malfunction. Additionally, I printed casing and supports for the electric components this weekend. I took time to measure the electric components and brainstormed ways to neatly compact them in a box where there would be no wires in sight in my final presentation. I also had to find a way for the support that would elevate the spiral case, which could nicely line up with the stepper motor, because the metal rod goes through the spiral and attaches to the stepper motor. For now, the grey elevating support in the picture is perfect, however, the black casing box is currently being reprinted because the stepper motor is too tight and does not fully fit in width. Other than that, the casing and support should be perfect in no time.

Also, I have to wait on a piece for the Raspberry Pi because it needs a dependent to take control of the pulse time. After testing the stepper motor over a long period of time, we noticed that the motor was sounding funky toward the end of the given number of steps. So if we told it to move 200 steps which is a rotation of 180 degrees clockwise, it would make a weird sound at the end of its cycle. This has to do with not having time to keep a constant pulse so that the stepper motor can be under control and in sync with the give commands.

Next week I will be focusing on calibrating as I mentioned at the beginning of my post. I hope to create a Python library, meaning a conversion table to cross between motor rotation and unit measurement. If the user asks for 2 cups of rice, I would be able to access the library and easily get the number of steps the stepper motor should make. This will be more testing to see how much one spiral can hold in each section and its average weight. This will be the last component of my project to finally be able to have a minimum working voice-controlled dispenser. Hope to see you next week!

Hi, welcome to week 5, where the project faced multiple challenges. This week I started off the weekend with more 3D prints, mainly tweaking measurements in the prints. Below are images of the 3D print series I have compiled, keep in mind that is not all of them! This will be an ongoing theme where I will most likely still be doing tweaks to parts. I do still have to print out a part to finally replace the water bottle as a hopper and support for the entire structure itself. This will be done while I complete other parts of my project, as they will take long hours or even days.

Continuing with 3D printing, I was able to test the two model types more at the beginning of the week. I have established that I will be using the spiral mechanism. The reason behind this is because it jammed the least and when I printed a bigger version. This design was much smoother with testing and is now able to support substances from small grains of sugar to pinto bean size. Below I have included images of the spiral in its case with a rod through it and the view from different perspectives. I will have to reprint the black lid because it is currently on the looser side than I want.

Apart from 3D printing, I started to look into the implementation of the Alexa and Arduino. There were a lot of technical issues beginning with finding MAC addresses for them to register them on the college’s network. From there I was having difficulty trying to think of a way to connect my voice measure skill to the skill that many online sources were indicating that I needed to use in order to connect to the Arduino. At this point, it was later in the week and I know I need to move quickly. We decided that it was best to move on using a Raspberry Pi and the speech recognition Google API that a fellow DTSF peer is already using. This way it would be easier to connect audio and the motor components. I did have slow progress with this because I was also out for a day due to sickness. I also had difficulties with the Raspberry Pi, because although it is not the fastest alone, it did have issues with overheating and freezing the screen altogether. The lesson is to safe progress often. I started with the PyCharm IDE, which was recommended by peers, however, I think the Raspberry Pi was not responding kindly because of it. Therefore, I did have to switch to a different IDE, VSCode. I have used this IDE previously, so it was easier to work with. After many mishaps and technical issues, I finally got the Raspberry Pi to pick up on speech recognition. I will have to develop this code further next week to be able to cut the string that the audio picks up to be able to tell how much the user wants to measure and what they want to measure. I also got all the chords to the stepper motor, Raspberry Pi, and power to be all set. I have now to work on making the stepper motor working, which will be the first thing I do next week. Then the task is to implement these two components together and start calibrating to the different substances. Stay tuned for next week’s progress!

Welcome back to the progress of my project! This week I started off with a prototype of my phyisical device. I used a small tube to be a cast for the spiral mechanism. A water bottle as a hooper to hold the substance, in the picture I have places rice. I also had a paint brush to spin the spiral which is in side the tube because the spiral at the time could not fit a metal rod. This is something I had to address later on. I used the materials to quickly test if my deisgn would work before I printed any parts our. Fortunately, I was able to have rice dispensing from the bottom hole at the other end of the tube. In the image you can see that rice has gone through the spiral after a couple turns and fallen onto the plate.

Since the metal rod did not fit into the spiral and I had to use a paintbrush for now, as seen in the image above, I had to reprint the spiral with a different hole diameter through the center. That being said, this week I also focused on continuing to print parts for my prototype with slight measurement modifications. At first, I began printing the spiral design that I mentioned in last week’s post. I printed these spirals with different hole sizes for the metal rod that will spin the spiral. This cost me a lot of time to be able to test the spirals. However, once I began to progress with my 3D prints, I figured that I could print out smaller ring sample sizes to make sure things were fitting properly. This is better than waiting for an entire 3D object to print in order to test. The image above on the right is a design that supplies a paddle design inside the case that is different than the spiral. This design I imagine will be more useful for large substances such as beans.

This process was not smooth, there were some errors along the way. Below is an image of what I found at the lab the next day. I had put an 8-hour print and came back to this mess. Needless to say at this point, there were many prints made this week.

After printing a series of spirals and cases, I had many tests to conduct with different substances. Below is a test with Rice and beans. At the beginning of my tests, I experienced many jams with the paddle and the rice and beans. This was because of sizing and gaps inside between the spiral and case.

These are some images of the prototype, I am closer to a much smoother working mechanism. I also got the MAC addresses for the arduinos to register them on the network. Next week will be dedicated to connecting the Alexa and Arduino Wifi Board.