vs_apple_watch.mov
UPenn ESE 3500 Final Project
Will Sturgeon & Mostafa Afr
Extremely affordable custom wearable to monitor, display, and calculate heart rate abnormalities in real time.
Just run make. (This should install dependencies as well.)
- Bare-metal register-level C on the ESP32 with a manual build script & flashing routine
- Such a pain to write register-heavy C for the Feather, but worth it in the end
- E.g., some essential registers (like
SENS_SAR_SLAVE_ADDR1—I dare you to look it up) are just entirely absent from the manual
- E.g., some essential registers (like
- The official library (ESP-IDF) is undocumented and ~20x slower than this repo (extra safety checks)
- Such a pain to write register-heavy C for the Feather, but worth it in the end
- Scrolling display with interpolated lines, adjusted in real time to a moving average and running peak, all fast enough to display in real time
- Fixed-point division, aligned with real-world seconds (by some crazy unit math), without overflow on the full range of possible human heart rates
- Custom font by hand! Writes sideways as well!
- Displaying integers uses an array of function pointers, choosing an integer in O(1)
- Automatically write VSCode JSON when compiling for mouse-over config info (see
esp32/Makefile)
None at all.
Disclaimer: as noted above, the ESP32 manual is literally incomplete, and so if a module was not working after multiple hours of following the instructions and exhausting reasonable what-ifs, I would comb through an ESP-IDF implementation to see which registers were missing. None of their code survives in any form, and I thoroughly documented my code to demonstrate understanding and help my future self.
Current state of the project: https://youtube.com/shorts/ZsG0fzAm2Nc We have gotten the heart beat monitor to work properly with a feather in baremetal on the LCD, and are currently working on adding a pulse oximeter as the next feature!