Review on SunFounder I2C LCD Module Shield for Arduino R3 Mega2560 - 2004 20x4 Serial TWI by Adam Johnson

If you don't use an Arduino or Raspberry Pi, using it is a problem. All documentation and drivers assume that you will use one of them. I've been using microcontrollers for 40 years so I've managed to figure it out, with the MSP430 for example a beginner is unlikely to succeed. If you want to use it boneless, here are some tips. The I2C is converted to an 8-bit parallel port on a smaller board (which is soldered to the LCD board). The 8 parallel bits starting with MSB are as follows: D7, D6, D5, D4, Backlight, EN, RW, RS. Your first instruction should be to set the LCD to 4-bit mode. You can find the LCD and I/O Expander documentation online by searching "SHENZHEN EONE 1602" and "PCF8574".