But first, let me show a screenshot:

Prerequistes:

• RAMDISK mounted at /Volumes/ramdisk[number] Example (8GB ramdisk):

  diskutil erasedisk apfs tempramdisk$RANDOM $(hdiutil attach -nomount ram://$((1024*1024*8)))
  

• Arduino Application
• MacOS X (macOS)
• Heltec ESP32 (v1 and v2 are ok)

Usage:

Run command make to upload and connect to serial device. You can override these variables according to your needs:

• PORT: /dev/cu.[your_port_name], replace it with your board's
• BAUD: 115200, match it with the code (for monitoring purposes)
• BUILD: Temporary build location, you can use mktemp -d
• ARDUINO: Full path to your arduino binary. Including ./Content/MacOS/Arduino.

compile : compiles sources into `BUILD`.
upload  : compiles then uploads into `PORT`.
monitor : `cat`s device in given `PORT` with `BAUD`.
images  : generate header files from `.bmp` bitmap images.
ss.bmp  : pull screenshot from device.

Explanation of which file do what:

• snowflake-esp32.ino: ESP32 Application for Arduino.
• bitmap.h: Bitmap file and BMP format definitions, helper functions.
• screenshot.cc: Reads 0s and 1s from input and converts them to bitmap with given sizes as arguments.
• convert.cc: Reads bitmaps BMP files from input and converts them to C array. Note: C array does not have a name, its just HEX body. See snowflake-esp32.ino for example usage.

Credits:

• Icons/Snowflakes are taken from Adafruit: https://learn.adafruit.com/neopixel-matrix-snowflake-sweater?view=all Note: I took screenshot of screenshot (damn yeah!) and shrunk them to 8x8 using GIMP Then modified Levels/Curves to make them more black-white.

Note: Pulling screenshot from device may 'freeze' screen for a second :)