tomodachi/hxmg12232

My notes and code for the HXMG LCD Display

Notes for the LCD Display HXMG 12232-2B Rev A.

• Im unable to find any data sheet for this particular LCD
  but it seems fairly similair to other chips

• References to data for my assumptions below
  raspberry gpio tutorial: https://www.raspberrypi.org/documentation/usage/gpio/
  http://geoffg.net/SG12232A_Driver.html
  http://www.octagonsystems.com/Manuals/Display_CableAssemblies/LCD_4x20_4x40_Display_Cable_Manual.pdf

High / Low = On/ Off in GPIO

| GND | - Ground
| VCC | - (+5V to the chip?
| V0 | - (GND to the chip?)
| RS | - Register select signal H/L, Signal register/ Instruction input.
| NC | - NC = no connection?
| E2 | - H: talk to micro controller 2
| NC | - no connection
| E1 | - H: talk to micto controller 1
| RW | = H/L Read / Write H: chip puts already set data in BUS. L: Allows us to place data in BUS.
| DB0 | - Databus 1-7 ( only 4 are used in 4 bit mode, can this be set on this chip?)
| DB1 |
| DB2 |
| DB3 |
| DB4 |
| DB5 |
| DB6 |
| DB7 |
| RST | - Reset probably, most datasheets with similair chips say it RST on boot.
| A = | - PWR to backlight (+5v)
| K = | - PWR to backlight (GRND)

As far as i can understand this stuff to program the LCD:

1. Set Register Select to instruction input (otherwise is in some kind of framebuffer mode?!)
2. Set chip to talk in either 4 bit or 8 bit mode (how do we do that , or is it pre set to one of them?
3. Set which half of the display to talk to (E1 or E2)
4. Put chip i Write mode with RW
5. Use databus to LCD layout
6. Put chip in Read mode with RW

Data sheet also reference a pin called "E" , wich seems to be a H/L to indicate if chip is written / read from . Dont think any of the pins I have mapped are one of those

Yours truly
~tomodachi