LCM-WM002 is a 16×2 LCD display, coming from a “refurbished” equipment. To be true, the equipment was a HP 5000 / 5100 laser printer, and the LCD has a bezel and a PCB with buttons attached, named ESU19516, part number RG5-5438.

According to some internet sourse, like www.elektroda.pl or hardforum.com, this is a SPI interfaced LCD. The pinout as follows:

LCD Pin Connector pin Function Memo
1 Left LED, cathode green
2 Middle LED, cathode green
3 Right LED, cathode amber
4 not connected?
5 to switch 0?
6 to switch 1?
7 to switch 2?
8 to switch 3?
9 to switch 4?
10 to switch 5?
11 to switch 6?
12 to switch 7?
13 to switch 8?
14 3 CS
15 2 CLK
16 5 MISO
17 4 MOSI
18 1 +3,3 V VCC
19 7 +5 V for backlight
20 6 GND

Switches are low while pushed.

The possible interfacing is on www.elektroda.pl:

Bit 15 (MSB) 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 (LSB)
Function RS E LED 1 LED 2 LED 3 LED 4 LED 5 Backlight
Memo Bity 8-15 – ZANEGOWANE dane dla wyświetlacza. Bit 15 jest najbardziej znaczący oraz w nim zapisujemy MSB danych dla HD66710. state of the RS line: 0 for data, 1 for instructon state of the E line on the HD66710, active LOW active LOW active LOW active LOW active LOW active LOW active LOW

To be continued.