Step 1: Connections

RST to D6 or any digital
CE to D7 or any digital
N/C
DIN to D11/MOSI
CLK to D13/SCK
VCC to 3.3V
BL to 3.3V or via resistor to any digital pin
GND to GND

Connections are similar to Nokia 5110 LCD and most of SPI displays. The only difference is that there is no DC (data/command) pin. This information is sent via 9-bit SPI.

LCD works best at 3.3V, 5V is safe too but requires changes in contrast settings. The easiest way is to use Arduino Pro Mini powered from 3.3V source.

Step 2: Comparison to Nokia 5110 LCD

HX1230 is advertised as Nokia 5110 LCD replacement. This is not entirely true because HX1230 has different controller/command set and requires other library

Advantages of HX1230:

much smaller display PCB but screen size is almost the same
no zebra strip, display is soldered to PCB
little higher resolution 96x68 vs 84x48
better aspect ratio, pixels are square
only 1 LED used for backlight
1 wire less required to connect it to MCU (no DC pin)
usually cheaper than N5110 - $1.60 vs $1.80

Step 3: Arduino Software

Prepared 2 different libraries:

Low resource library used for simple projects with mostly alfanumeric data (however rendering pixel graphics/bitmaps is still possible), doesn't use RAM for frame buffer, everything is rendered directly to LCD via SPI
https://github.com/cbm80amiga/HX1230_SPI
Full graphics library with dithering support:
https://github.com/cbm80amiga/HX1230_FB

Watch next step video to check libraries features

Step 4: Watch the Video

Features:

proportional fonts support built-in (requires fonts from PropFonts library https://github.com/cbm80amiga/PropFonts)
simple primitives (pixels,lines,rectangles,filled rectangles,circles,filled circles,triangles,filled triangles)
fast ordered dithering (17 patterns)
ultra fast horizontal and vertical line drawing
bitmaps drawing
many example programs