ERM19264_UC1609_PICO

Table of contents

• Overview
• Hardware
• Software
  • SPI
  • Fonts
  • Bitmaps
  • User adjustments
  • File system
• Notes and Issues

Overview

• Name : ERM19264_UC1609
• Title : Library for ERM19264-5 v3 LCD (UC1609C controller)
• Description :

1. Raspberry pi PICO RP2040 library.
2. Inverse, Scroll, rotate and contrast control.
3. 10 ASCII fonts included.
4. Graphics class included.
5. Sleep mode.
6. Bitmaps supported.
7. Hardware SPI options
8. Polymorphic print class included to print many data types.
9. Port of my arduino library , More details there.

• Author: Gavin Lyons
• Developed on
  1. Raspberry pi PICO RP2040
  2. SDK C++ compiler G++ for arm-none-eabi
  3. CMAKE , VScode

Hardware

9 pins , Vcc and GND, anode and cathode for the backlight LED and an SPI interface. The backlight control is left up to user. The CLK and Data lines are fixed to the SPI interface but any GPIO can be used for reset, DC and CS.

There are 3 different colours in range, Parts used purchased from ebay

1. ERM19264SBS-5 V3 LCD Display UC1609C controller , white on blue
2. ERM19264FS-5 V3 LCD Display UC1609C controller , black on white
3. ERM19264DNS-5 V3 LCD Display UC1609C controller white on black

The library was tested on 1 and 2. This wiring Diagram from the manufacturer showing hardware setup connected to an ~8051 MCU, showing both 3.3 volt and 5 volt systems.

Software

API Documentation

The Software is commented mostly for "doxygen" and if users uses "doxygen" software an API document can be generated. A Doxyfile is in "doc" sub folder in repository.

SPI

Hardware SPI. The hardware SPI speed is set at 8MHz you can change this if necessary by changing LCDSPISetup method arguments. Spi0 is used in example files but can be changed by passing a different SPI channel.(Spi0 or Spi1)

Fonts

There are 10 fonts packaged with library. Fonts can be easily added or removed by user. All the Font data is in the font files.

Font data table:

num	Font pointer name	character size XxY	ASCII range	Size in bytes
1	pFontDefault	6x8	0 - 0xFE, Full Extended	1534
2	pFontWide	9x8	0x20 - 0x5A, NO lowercase letters	535
3	pFontPico	4x6	0x20 - 0x7E	289
4	pFontSinclairS	8x8	0x20 - 0x7E	764
5	pFontMega	16x16	0x20 - 0x7E	3044
6	pFontArialBold	16x16	0x20 - 0x7E	3044
7	pFontHallfetica	16x16	0x20 - 0x7E	3044
8	pFontArialRound	16x24	0x20 - 0x7E	4564
9	pFontGroTesk	16x32	0x20 - 0x7A	5828
10	pFontSixteenSeg	32x48	0x2D-0x3A , 0-10 : . / - only	2692

Font size in bytes = ((X * (Y/8)) * numberOfCharacters) + (4*ControlByte)

Font class Function	Notes
writeChar	draws single character
writeCharString	draws character array
print	Polymorphic print class which will print out many data types

These methods return an error code in event of an error such as, ASCII character outside chosen fonts range, character out of screen bounds and invalid character array pointer object.

Remove a font

To remove an unwanted font from project simply comment out or delete.

1. The Font data in ERM19264_UC1609_font.cpp file
2. The pointer to font at bottom of ERM19264_UC1609_font.cpp file
3. The associated extern pointer declaration in the ERM19264_UC1609_font.hpp file

Adding a new font

1. Add the Font data in ERM19264_UC1609_font.cpp file
2. Add a pointer to font at bottom of ERM19264_UC1609_font.cpp file
3. Add an associated extern pointer declaration in the ERM19264_UC1609_font.hpp file

The new ASCII font must have following font structure. First 4 bytes are control bytes followed by vertically addressed font data.

// An 4 by 8 character size font starting at 
// ASCII offset 0x30 in ASCII table with 0x02 characters in font. 
// 0 and 1 
static const uint8_t FontBinaryExample[] =
{
0x04, 0x08, 0x30, 0x02,   // x-size, y-size, offset, total characters
(data),(data),(data),(data) // font data '0'
(data),(data),(data),(data) // font data '1'
}

Some of the fonts packaged with library came from URL. If user has picture of a font like so.

There is a monochrome font maker there at URL

Bitmaps

There is a few different ways of displaying bitmaps,

Num	Method	Data addressing	Note
1	LCDBitmap()	Vertical	Writes directly to screen , no buffer used.
2	LCDBufferScreen()	Vertical	For internal use mostly
3	drawBitmap()	Vertical	default, setDrawBitmapAddr(true)
4	drawBitmap()	Horizontal	setDrawBitmapAddr(false)

The drawBitmap method will return an error if : The Bitmap is completely off screen , Invalid Bitmap pointer object, bitmap bigger than screen , bitmap bigger/smaller than provided width and height calculation ( This helps prevents buffer overflow). A vertical addressed Bitmap's height must be divisible by 8. eg, for a bitmap with width=128 and height=64. Bitmap excepted size = 128 * (64/8) = 1024 bytes. A horizontal addressed Bitmap's width must be divisible by 8. eg, for a bitmap with width=88 and height=48. Bitmap excepted size = (88/8) * 48 = 528 bytes.

Bitmaps can be turned to data here at link See example file "BITMAP" for more details.

User adjustments

If the LCD does not initialize correctly. Try adjusting the RAM address control setting from 0x02(default) to 0x01. See github issue 4(arduino Source port) for details. Users can adjust setting in the "begin" method argument list. This setting changes bits 2-0 in AC register, see diagram below for details.

When the user calls LCDinit() to start LCD they can specify a contrast setting from 0x00 to 0xFF. Datasheet says 0x49 is default. (VbiasPOT). Lower contrast works better on the blue color version.

It is also possible for user to change LCD bias, Temperature coefficient, frame rate and power control but this must be done by changing defines in header file. Choose lower frame rate for lower power, and choose higher frame rate to improve LCD contrast and minimize flicker. See Data sheet for range of values here. Defaults where found to be fine during all testing of this library.

Parameter	default Values	Define	Register bits
LCD bias	9	BIAS_RATIO_SET	BR 1:0
Temp coefficient	-0.00%/ C	TEMP_COMP_SET	TC 1:0
Frame rate	95 fps	FRAMERATE_SET	LC 4:3
Power control	1.4mA + Internal VLCD (7x charge pump)	PC_SET	PC 2:0
V bias Bot(contrast)	0x49	Set by user with LCDinit	PM 7:0
Ram Address Control	0x02	Set by user with LCDinit	AC 2:0

File system

X = ERM19264_UC1609 in tables below

Src Files	Description
X.hpp	library header file
X.cpp	library source file
X_graphics.hpp	graphics header file
X_graphics.cpp	graphics source file
X_font.hpp	font header file
X_font.cpp	font data file
X_print.hpp	used for printing data types
X_print.cpp	used for printing data types

The example files are in example folder. To build the one you want, edit the Cmaketxt file add_executable(${PROJECT_NAME} section, comment in one example file path and one only. The default is the Hello world one.

Examples files main.cpp	Description
X_HELLO	Hello world , Basic usage
X_TEXT_GRAPHICS	Text + graphics
X_FUNCTIONS_FPS	FPS test & misc functions, rotate , scroll, etc
X_BITMAP	Shows use of bitmaps methods

Notes and Issues