I'm unclear on whether I'm clueless, but I was unable to get the driver code provided by Waveshare working with the ESP32, but did get it working with a Raspberry Pi. Speaking of which, I don't understand why anyone would use an RPi that idles at 2-3 watts with an E-paper display. Regardless, I analyzed the Python code for the RPi and used it to create an Arduino library.
I've specifically tested this with an Inland ESP32 Core Board, but it should work on most (read: all) ESP32 dev boards and other Arduino devices.
| e-Paper HAT | ESP32 | |
|---|---|---|
| VCC (Grey) | <-> | 3.3v |
| GND (Brown) | <-> | GND |
| DIN (Blue) | <-> | IO13 |
| CLK (Yellow) | <-> | IO14 |
| CS (Orange) | <-> | IO15 |
| DC (Green) | <-> | IO23 |
| RST (White) | <-> | IO33 |
| BUSY (Purple) | <-> | IO27 |