ERM19264_UC1609

Table of contents

• Overview
• Output
• Installation
• Hardware
• Software
  • API Documentation
  • SPI
  • Buffer
  • Fonts
  • Bitmaps
  • User adjustments
  • Example files
• Tested MCU

Overview

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

1. Arduino eco-system library.
2. Inverse, Scroll, rotate and contrast control.
3. 12 ASCII fonts included.
4. Graphics class included.
5. Sleep mode.
6. Multi-screen shared buffer mode.
7. Bitmaps supported.
8. Hardware & software SPI options
9. Light weight basic text version here at link.
10. Software may also work with ERM19264 LCD controlled by ST7525 controller but untested at current time.

• Author: Gavin Lyons
• URL : Github URL link

Output

Output Screenshots, From left to right top to bottom.

1. Full screen bitmap displayed
2. Multi-screen shared buffer mode, In this case screen divided into two.
3. Different size and inverted default font
4. ASCII font 1-127 printed out with default font size 1
5. Fonts 7-8
6. Fonts 1-4

Installation

The library is included in the official Arduino library manger and the optimum way to install it is using the library manager which can be opened by the manage libraries option in Arduino IDE.

Hardware

9 pins , Vcc and GND, anode and cathode for the backlight LED and an SPI interface. The example files are setup for an UNO for the pin connections used by for other MCU tested see extras folder GPIO_MCU_used.txt file. The backlight control is left up to user. If using Hardware SPI two of pins will be tied to the SPI CLK and MOSI lines if using software SPI you should be able use any GPIO you want for all five pins. Datasheet links are in the extras folder.

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 API (application programming interface) documentation is at link hosted on github pages and generated by Doxygen.

API URL

SPI

Hardware and software SPI. Two different class constructors. User can pick the relevant constructor, see examples files. When running Software SPI it may be necessary on very high frequency MCU's to change the SW SPI GPIO delay(LCDHighFreqDelaySet) It is a microsecond delay by default it is at 0. All the hardware SPI settings are defined in the header file and can be easily changed if necessary. It should be able to share SPI bus with other SPI devices on different SPI settings.

Buffer

The library features a multi-screen shared buffer mode, In order to save data memory for devices with low data memory. For example if user defines a buffer to cover the whole screen it takes 1536 bytes of data memory. Instead a user (for example) can create a buffer that covers half the screen for just 768 bytes then define two screens objects each pointing to the same buffer. The user uses the 'ERM19264_UC1609_Screen' Class objects to define each screen and the 'ActiveBuffer' pointer to switch the buffer between each screen. Multiple screens of same size can be created so LCD screen can be divided into thirds or quarters saving even more memory. The disadvantage of this is the code is slightly more complicated and user can only write to one screen at a time. If user does not want to use multi screen mode they can simply just define ONE screen to cover entire LCD screen. See example files and API for more detail.

Figure :: The class structure with three screen object's and active buffer presently pointing to number one.

Fonts

Font data table:

num	enum name	Char size XbyY	ASCII range	Size bytes	Size Scale-able
1	$_Default	5x8	0-0x7F	635	Y
2	$_Thick	7x8	0x20-0x5A, no lowercase letters	406	Y
3	$_SevenSeg	4x8	0x20-0x7A	360	Y
4	$_Wide	8x8	0x20-0x5A, no lowercase letters	464	Y
5	$_Tiny	3x8	0x20-0x7E	285	Y
6	$_Homespun	7x8	0x20-0x7E	658	Y
7	$_Bignum	16x32	0x2D-0x3A ,0-10 - . / :	896	N
8	$_Mednum	16x16	0x2D-0x3A ,0-10 - . / :	448	N
9	$_ArialRound	16x24	0x20-0x7E	4608	N
10	$_ArialBold	16x16	0x20-0x7E	3072	N
11	$_Mia	8x16	0x20-0x7E	1520	N
12	$_Dedica	6x12	0x20-0x7E	1152	N

1. $ = UC1609Font
2. Fonts 1-6 are byte high(at text size 1) scale-able fonts, columns of padding added by SW.
3. Font 7-8 are large numerical fonts and cannot be scaled(just one size).
4. Fonts 9-12 Alphanumeric fonts and cannot be scaled(just one size)

Font Methods:

Font num	Method	Size parameter	Notes
1-6	drawChar	Y	draws single character
1-6	drawText	Y	draws character array
7-12	drawChar	N	draws single character
7-12	drawText	N	draws character array
1-12	print	~	Polymorphic print class which will print out many data types(arduino built in)

These functions return a enum( LCD_Return_Codes_e), non-zero in event of an error, see API doc. By default only Font 1 is commented in and ready to go to save memory. So to use a non-default Font (2-12), two steps. Comment in the respective define at top of library header file ERM19264_UC1609_graphics_font.h in the USER FONT OPTION ONE section Call SetFontNum method and pass it name of respective font. eg SetFontNum(UC1609Font_Wide).

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	LCDBuffer()	Vertical	Mostly for internal use ... mostly
3	buffer init technique	Vertical	Can be used when initialising a buffer, splash screen
4a	drawBitmap()	Vertical	default, setDrawBitmapAddr(true)
4b	drawBitmap()	Horizontal	setDrawBitmapAddr(false)

The drawBitmap function will return an enum with an error code if an error occurs see API docs. See the bitmap example file for more details on each method. Bitmaps can be turned to data here at link , Bitmaps should be defined in the program memory and buffers in the data memory.

User adjustments

Some users have reported the LCD not initialising correctly with this software. It was found that by adjusting the RAM address control setting from 0x02 to 0x01. it resolved problem. See github issue 4 for details. I suspect the root cause is different versions of product on market. As of Version 1.7 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 LCDbegin() 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 LCDbegin	PM 7:0
Ram Address Control	0x02	Set by user with LCDbegin	AC 2:0

Example files

Examples files ino	Description
BITMAP	Shows use of bitmaps
GRAPHICS	Tests use of graphics
MISC	Shows misc functions, rotate, invert etc
MULTISCREEN	Shows use of multi screen mode + FPS, two screens
MULTISCREEN_TWO	Shows use of multi screen mode, four screens
TEXT	Shows use of text and fonts, All Fonts must be enabled to work fully
SWSPI	Shows use of software SPI
HELLO	Hello world, basic use case

Tested MCU

Tested on following MCUs both software and hardware SPI, The example files are setup for an UNO for the pin connections used by for other MCU testing see extras/doc folder GPIO_MCU_used.txt file.

1. Arduino UNO & NANO v3
2. ESP8266
3. ESP32
4. STM32 "blue pill"
5. UNO Minima R4

Notes and Issues