Category: Meera’s Status Updates

Accomplishment: This week I connected the Jetson to battery power by using a USB to barrel jack cable to connect the Jetson to a rechargeable power bank. I also started designing the casing in Autodesk Fusion to laser cut or 3d print, and I started working on the final presentation slides.

Progress: I am behind in progress. I flew out to see family due to a family emergency this week and was not able to work on improving or testing the hardware components.

Projected Deliverables: This week I plan to finish the casing CAD file and laser cut a prototype, and solve the ultrasonic sensor issue. I will also reach out to LAMP to possibly set up a user testing time before our final demo.

As you’ve designed, implemented and debugged your project, what new tools or new knowledge did you find it necessary to learn to be able to accomplish these tasks? What learning strategies did you use to acquire this new knowledge?

For the project, I’ve learned a lot about circuit design, PCB design, GPIO configuration, and Jetson setup. For circuit and PCB design, circuits weren’t my strongest area before starting the project, so I spent a lot of time watching videos about similar projects, reading through circuits reference information, and prototyping circuits using breadboards or TinkerCAD simulations. For the GPIO configuration, I also looked into similar projects and found GitHub repos of GPIO configuration libraries that we could use. When setting up the Jetson, I ran into a lot of permissions issues regarding library and package installation and GPIO configuration, and had to learn how to modify permissions settings, and I became a lot more comfortable with Linux terminal commands. I found practice to be the best way to understand the concepts I was looking into, so I did a lot of trial-and-error problem solving and prototyping. I was also working on electrical projects for booth at the same time as working on this project, so I was also able to practice circuits, GPIO usage, and Linux command line tools doing those projects as well.

Accomplishment:  This week, I developed a prototype casing for our device out of cardboard for the interim demo. Afterwards, I ordered the battery packs and adapters for the Jetson, which will allow us to actually wear the device instead of relying on power from an outlet. Lastly, I connected the Jetson to internet using my Wifi router and installed python3.8, espeak, pyttsx3, and numpy onto the Jetson. I attempted to install pytorch but ran into issues and asked Josh to look into the installation since it is needed for the OR model.

Progress: I am on track with my progress now that all subsystems of the PCB seem to be working and the battery pack has been ordered. 

Projected Deliverables: This week, I will work on designing the device casing, which we will likely laser cut and assemble, and will look into getting a strap for wearing the device. Once we get the carrying strap, I will integrate the vibration motor into the strap and ensure that the wearer can feel the vibration motor through the strap. Lastly, I will reach out to LAMP to set up user testing times.

Verification: For verifying the hardware components, specifically the PCB, we wrote software programs to test each individual component (buttons, vibration motor, and ultrasonic sensor). The components seem to function individually, but Shakthi and I have experienced some issues running the proximity module code, since the ultrasonic sensor tends to hang while waiting for the echo pulse. To identify the source of the issue, we will test the code using a breadboarded ultrasonic sensor instead of the PCB-mounted sensor and will use an oscilloscope to verify that the signals sent between the Jetson and PCB are expected values. This will tell us whether a transient signal on the PCB is interfering with the sensor readings, or if our software needs to be modified. Now that the rechargeable battery pack has arrived, I will also begin running the Jetson on battery power. To do this, I will fully charge the battery pack and run the Jetson for as long as possible to verify whether it meets our 4-hour requirement. I will also leave the battery pack idle for several hours then check the charge again, to see how much power drains when the Jetson is not in use. Since we ordered two battery packs, we may be able to connect both to the Jetson in case the power or battery life is insufficient.

Accomplishment: This week I set up a network connection on the Jetson by connecting it directly to a Wifi router, which allowed me to install pip and a GPIO library. After resolving multiple permissions errors, I was able to run some sample GPIO control tests using the library.  Since I still had not heard anything about the transistors for the PCB being delivered, I tried soldering wires to the PCB so that I could use a breadboard transistor, but in doing so I broke one of the solder pads on the PCB. I also placed an order for the USB audio output converter.

Progress: I had planned to finish populating the PCB this week, but was set back since the transistors still hadn’t arrived. I contacted Quinn about the order, and he said the transistors had been delivered but I wasn’t contacted about them, so he will check for them on Monday. This put me behind schedule, but since the transistor is only used for interfacing the vibration motor with the Jetson, I am still able to test the buttons and ultrasonic sensor using the PCB. I am behind on my progress due to the transistor delay, but hopefully I will be back on track after assembling the new PCB.

Projected Deliverables: This week I plan to populate a new PCB since the first version broke. I will test the buttons and ultrasonic sensor using the PCB, and will solder the transistors and test the vibration motor once I get the transistors from receiving. Once the audio converter is delivered, I will work with Shakthi to develop the test-to-speech audio output.

Accomplishment: This week I populated the PCB with all components except for the N-MOS transistors which haven’t arrived yet. I also flashed the Jetson’s microSD card with the developer kit SD card image and began setting up the Jetson.

Progress: I had planned to finish populating the PCB this week, but was set back since the transistors were not available in the campus lab rooms and I had to place an order for them. This put me behind schedule, but since the transistor is only used for interfacing the vibration motor with the Jetson, I am still able to test the buttons and ultrasonic sensor using the PCB. 

Projected Deliverables: This week I plan to test the buttons and ultrasonic sensor using the PCB, and will solder the transistors and test the vibration motor once the transistors are delivered. To test the PCB, now that the Jetson has been set up, I will also write the GPIO setup code using the RPi.GPIO Python library. Lastly, I will place an order for the USB audio converter so that we can integrate audio output with the Jetson.

Accomplishment: Since 2/24, I designed the PCB we will use to connect our hardware components to the Jetson. I also placed orders for the PCB and other remaining hardware components for our device, which were delivered over break. 

Progress: Even though I fell behind in designing the PCB before break, the PCB and other components were still delivered during break so I will be able to assemble them this week. Because of this, my progress is back on track for PCB development. The one thing I am behind on is ordering the USB-to-headphone audio converter from Amazon, but since Amazon has 2-day shipping, I will be able to place the order this week and receive the component soon.

Projected Deliverables: This week I plan to assemble the PCB and order the audio converter. I will also test the PCB with the components that have been delivered already, so that I can make adjustments to the design (if needed) as soon as possible.

Accomplishment: This week I presented for the team’s design presentation, so I spent the first half of the week practicing the presentation. On Tuesday, I met with the visual impairment advisory board at the LAMP, where I introduced our project idea and received feedback and suggestions for our implementation, and gauged interest for user testing later in the semester. We got feedback on incorporating some additional objects to identify in our ML model, and we will stay in contact with LAMP to set up user testing later in the project timeline. I briefly looked into the circuits necessary for voltage conversion for our PCB, but unfortunately got sick after the design presentation and wasn’t able to complete the PCB design this week.

Progress: Since I wasn’t able to complete the PCB design this week, I am behind schedule on getting the PCB ordered. I still plan on finishing the design before spring break, so that the order can be placed and will arrive after break.

Projected Deliverables: This week I will catch up with the PCB design and place orders for our remaining hardware components. I plan to order the PCB from a site with a turnaround time of ~1-2 weeks, so that I can still assemble and test the PCB as soon as possible after spring break.

Accomplishment: This week I researched using a Jetson vs RPi to help us decide which board to use. I also researched using the Jetson’s GPIO pins, looked through NANO pinout documentation, and found libraries for configuring the Jetson NANO’s pins. I also looked into existing projects that integrate a Jetson with sensor peripherals to get guidance on designing the custom PCB. I looked into specific devices for our audio output and vibration motor and settled on the CM108 board for audio conversion. Additionally, I called LAMP to get project feedback from visually impaired people and set up a meeting for this Tuesday 2/20.

Progress: My progress is on track this week since I set up the meeting with LAMP and looked into hardware components. My schedule for next week has changed slightly to accommodate circuit design, but I don’t expect this to throw off my overall progress on component integration since the hardware components we ordered have not arrived yet.

Projected Deliverables: This week I will be giving our design presentation as well as meeting with the LAMP advisory group on Tuesday, so I will work on preparing the slides and presentations. I will also begin designing and testing the voltage conversion circuit in preparation for our hardware components arriving. I also plan on placing an order for the audio converter and vibration motors we settled on.

Accomplishment: In the past week, I looked into hardware options for our device, specifically comparing TOF cameras to basic cameras. I learned that TOF cameras have less precision compared to a sensor dedicated solely for distance estimation, but this choice of hardware will make it easier for us to integrate object recognition with distance estimation, as opposed to our previous plan of integrating cameras with ultrasonic sensors. I also put together a Notion planning page for the team to keep track of our timeline, tasks, notes, and resources. We also had a team meeting to discuss feedback from our proposal and decide on any design changes, for which I created a new block diagram to reflect the new design. Lastly, I got in touch with a volunteer at LAMP to get the contact information of the volunteer coordinator.

Progress: This progress is on schedule with our initial timeline for research and ordering materials. However, since we decided to consider using the NVIDIA Jetson in place of the Raspberry Pi for better performance, I will be making more time to research single-board computers before our parts order goal of Wednesday 2/14.

Projected Deliverables: This week, I plan to continue looking into specific cameras and sensors so we can place an order by 2/14. I also plan to compare the performance and specifications of a Raspberry Pi vs. NVIDIA Jetson, so we can request one from the ECE inventory by 2/14 and begin using it by the end of the week. I will also contact LAMP’s volunteer coordinator on Monday 2/12 to set up a time for us to speak to visually impaired people and receive suggestions for our device’s features.