Notes on using the Newhaven Display LCD panels with TTL level RS-232 serial
interface (NHD-0420D3Z-NSW-BBW).

Only pins 1, 2 and 3 are used.

1: Data
2: Ground
3: Power (+5v)

The serial link uses 9600 bits/second (8-bit data, 1 stop bit, no parity).
The link uses TTL-serial signaling (0 to 5V), not RS-232 levels (-8v to +8v).

Commands are sent to the LCD by sending a 0xFE followed by the one or more
command bytes, the number command bytes depends on which command is being sent.

This sequence seemed to work for initializing the panel.

	delay 500ms                         Probably not needed but can't hurt
	Send the command 0xfe, 0x51         Clear screen
	Send the command 0xfe, 0x53, 0x04   Set backlight level to 4

To move the cursor, use the command sequence 0xfe, 0x45, "pos", where "pos" is
a number between 0 and 0x67.

1st row: 0x00 to 0x13
2nd row: 0x40 to 0x53
3rd row: 0x14 to 0x27
4th row: 0x54 to 0x67

For other commands, see the datasheet.

To display data, just send the ASCII code for the character (from 0x20 to
0x7F).