The official firmware will be MicroPython-based.  However, I wanted to document an Arduino sketch and libraries that can be with the e-paper display on the bage.

The GitHub repo is here:

https://github.com/oshwabadge2018/arduino-epaper-demo

Instructions:

• Install the latest Arduino IDE and add the ESP32 board options to the Board Manager:
  • https://dl.espressif.com/dl/package_esp32_index.json
• Make sure the board is set to "ESP32 dev module"
• Make sure the serial port is the serial adapter.
• Wire up GND, RX, TX to the FTDI.
• Connect the IO0 pin to GND.
• Insert Batteries
• The module should power up and go into programming mode (IO0 low on powerup or reset)
• Click program in the Arduino IDE.
• The board should program.
• Un-ground IO0 and remove and reinsert the batteries.
• If this does not work then swap RX and TX and repeat the process

Methods to connect the wires:

• remove battery back to expose the bottom of J1 header and solder a 6 pin header on J1
• solder wires to J1 on the front the badge (and leave battery pack in place)
• use a 6 pin pogo pin adapter. I used an AVR ISP pogo pin adapter and connected to an 3.3V FTDI cable from Adafruit
• gallery of photos: https://photos.app.goo.gl/rP3fTZDd6UUGbDtt9 
  (I may try to do a diagram in the future, but wanted to link to photos in the meantime)