Table of contents

• Overview
• Output
• Installation
• Hardware
• Features
• Files
• Tested
• Ports

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. 6 ASCII fonts included.
4. Graphics class included.
5. Sleep mode.
6. 3 different modes: Multi-buffer , single buffer , light weight text only
7. Bitmaps supported.
8. Hardware & software SPI options

• Author: Gavin Lyons
• Arduino IDE: 1.8.10
• History: See Changelog in extras/doc folder
• Copyright: GNU GPL v3

Output

Output Screenshots, From left to right top to bottom.

1. Full screen bitmap displayed
2. Multi buffer mode screen divided into two buffers
3. Different size and inverted default font
4. ASCII font 1-127 printed out with default font size 1
5. Fonts 5-6
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.

See link below for instruction for this and for the other methods too.

Installing Additional Arduino Libraries guide

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. Datasheets 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. The Backlight should always be connected to 3.3V according to datasheets.

The ERM LCD module has a "662k" 3.3V regulator at back and by default setup is a 3.3V device. However if can also be run at 5V and connect to 5V device by Modifying jumper J1 on back. This wiring Diagram from the manufacturer showing hardware setup connected to an ~8051 MCU, showing both 3.3 volt and 5 volt systems. NOTE the J1 position. If J1 is shorted the LCD can connect to 5V , J1 bypasses the 3.3V regulator.

Features

SPI

Hardware and software SPI. Two different class constructors. User can pick the relevant constructor, see examples files. Hardware SPI is recommended, far faster and more reliable but Software SPI allows for more flexible GPIO selection and easier to port to other MCU' s. When running Software SPI it may be necessary on very high frequency MCU's to change the UC1609_HIGHFREQ_DELAY define, 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.

buffers

3 buffer modes

1. MULTI_BUFFER (default)
2. SINGLE_BUFFER
3. NO_BUFFER , Text only no buffer , relatively light weight. Turns LCD into simple character LCD(216 characters). Default font only. Bitmaps can still be written directly to screen but no graphics possible.

To switch between modes, user must make a change to the USER BUFFER OPTION SECTION at top of ERM19264_UC1609.h file. Pick ONE option and one option ONLY. The example files at top, say which option to pick. If wrong option is picked, example files will not work or maybe even compile.

fonts

There are six fonts. A print class is available to print out most passed data types. The fonts 1-4 are a byte high(at text size 1) scale-able fonts. Font 5-6 are specials large fonts but are numbers only and cannot be scaled(just one size).
Font 5-6 will print just numbers + semi-colons , if you print a float using print command it will place a space and use a circle for a decimal point.

Font data table:

Font num	Font name	Font size xbyy	ASCII range	Size in bytes
1	Default	5x8	Full Extended ASCII 0 - 0xFF	1275
2	Thick	7x8	no lowercase letters , ASCII 0x20 - 0x5A	406
3	Seven segment	4x8	ASCII 0x20 - 0x7A	360
4	Wide	8x8	no lowercase letters, ASCII 0x20 - 0x5A	464
5	Big Nums	16x32	ASCII 0x30-0x3A ,Numbers + : only	704
6	Med Nums	16x16	ASCII 0x30-0x3A ,Numbers + : only	352

By default only Font 1 is commented in and ready to go to save memory. So to use a non-default Font (2-6), two steps.

1. Comment in the respective define at top of library header file ERM19264_UC1609_graphics_font.h in the USER FONT OPTION ONE section
2. Call SetFontNum function and pass it number of respective font. eg SetFontNum(2)

font mods

The default ASCII font (font one) is an extended ASCII font 0-255 characters. If you do not need characters 127-255 and wish to save memory space: In library header file ERM19264_UC1609_graphics_font.h in the USER FONT OPTION TWO section Simply comment this define out.

1. UC_FONT_MOD_TWO (save 640 bytes) extended ASCII 127-255

You can also remove the first 30 characters if not needed but user will need to change ERM19264_ASCII_OFFSET from 0x00 to 0x20. This will save a further 150 bytes.

bitmaps

Bitmaps are written directly to screen unless Bitmap set to a buffer. Best to use multi-buffer to share screen between bitmaps and text + graphics. Bitmaps can be turned to data here at link use vertical addressing draw mode.

User adjustments

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 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
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 V LCD	PC_SET	PC 2:0
V bias Bot(contrast)	0x49h default	Set by user with LCDbegin	PM 7:0

Functions

Functions: Detailed information on the functions can be found in comments in the ERM19264_UC1609.cpp file and a list of them in keywords.txt. The graphic functions can be found in the ERM19264_graphic.h file.

Files

Src Files	Desc
ERM19264_UC1609.h	library header file
ERM19264_UC1609.cpp	library source file
ERM19264_graphics.h	Custom graphics header file
ERM19264_graphics.cpp	Custom graphics source file
ERM19264_graphics_font.h	Custom graphics font file

Examples files ino	Desc	Buffer mode
BITMAP	Shows use of bitmaps	Several see notes
GRAPHICS	Tests use of graphics	Multi_buffer
MISC	Shows misc functions, rotate, invert etc	Multi_buffer
MULTIBUFFER	Shows use of multi buffer mode	Multi_buffer
NOBUFFER	Shows use of no buffer text only mode	No_buffer
TEXT	Shows use of text and fonts, Fonts must be enabled	Multi_buffer
SINGLEBUFFER	Shows use of single buffer mode	Single_buffer
SWSPI	Shows use of software SPI	Multi_buffer
HELLO	Hello world basic use case	Multi_buffer

Tested

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"

Ports

• ERM19264_UC1609_RPI , Raspberry pi C++. Link

• ERM19264_UC1609_T (T for text). Light weight Text only version for arduino ecosystem Link

• PIC xc8 Link

• Stm32cubeIDE STM32F070RBT6 C++ Link