Author: ladiga

What I did:

• Programmed the MCU (code can be found here) to connect with my phone via Bluetooth through the LightBlue BLE test app.
  • The MCU now sends accelerometer data to the phone (we have tested from 0.1 times/sec to 1 time/sec), and can receive vibration commands from the phone.
• Programmed the MCU to deploy these vibration commands to the LRA.
  • Added mux functionality to this code.
    • Createdan encoding scheme that encodes the vibration command and the LRA it should be sent to.
  •  Now we can send commands to the two LRAs in the device (necessary to provide vibration feedback to both sides of the leg). Created a suite of vibration test commands for LRA feedback testing.

• Wrote up documentation for how to program the MCU with this functionality, so each team member can interface with the Bluetooth communication independently.
• Tested the vibration feedback from the LRAs along with Rhea.
  • The LRA feedback was too faint to detect a difference among the different vibration commands, Rhea is focusing on getting greater power through to the LRA to increase its intensity.

On schedule?

I’m on schedule according to our Gantt chart. I have successfully programmed the IMU with bluetooth for IMU to laptop communication, and created test commands for the laptop -> LRA device pipeline.

Next week’s deliverables:

• Integrate IMU output into FPA estimation algorithm
• Test LRA feedback intensity
• Set up device on participant (one of our teammates), test feedback efficacy with no FPA estimation algorithm refinement

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).

• • This week I worked on getting communication between the ESP32 and the laptop working consistently. I was able to send simple commands to the ESP32  reliably, however I discovered that the ESP32 has to be put into bootloader mode each time I compile and flash new code on it. Below is a photo of all three of the onboard LEDs that were newly programmed to ON.

    

  • I placed an order for the parts for the wearable device. Beyond that, I specifically looked into using the Adafruit Flex Perma-Proto board for a greater degree of flexibility in our circuitry. One of the aims we have for this product is increasing user comfort while maintaining standards of accuracy set in the previous literature, I believe this flexible proto board is a step in this direction.
  • Along with the group I met with two PhD students working in the biomechanics lab for advice on our design. I focused on understanding the interface between existing FPA code and the signals we would get from our current IMU setup. I was able to clarify that we only need a 6 DoF IMU, and we can address drift by resetting the IMU position every footstep. They also pointed us towards VQF, a library for FPA estimation that is optimized for embedded applications.

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

• I had planned to get the full pipeline laptop -> MCU -> haptic driver -> LRA pipeline set up this week, however I was only able to get the MCU connected to my laptop. According to our Gantt chart, we are still on time for getting the full pipeline set up, since it is due ~2/11, so I will be scheduling time with Rhea and Kaitlyn to work on connecting the three devices on this upcoming Monday/Tuesday. This weekend, I plan on looking over the datasheets for the haptic driver and LRAs the PhD students loaned us to see how to set up code to send pulse commands to the vibration components before we get the pipeline ready.

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

• Connect MCU -> haptic driver -> LRA pipeline
• Access position data from IMU
• Familiarize myself with the VQF library
• Familiarize myself with the existing work on calculating FPA