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ERM19264 UC1609 Readme

ERM19264 image

Table of contents

Overview

  • Name : ERM19264_UC1609
  • Title : Library for ERM19264-5 v3 LCD (UC1609C controller)
  • Description :
  1. Dynamic install-able system level Raspberry Pi C++ library.
  2. Inverse, Scroll, rotate and contrast control.
  3. Sleep mode.
  4. Bitmaps supported.
  5. Hardware & software SPI options

Output

output image

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 , connect to 3.3V thru a resistor. If using Hardware SPI 3 pins will be tied to the SPI CEO, CLK and MOSI lines. if using software SPI you should be able use any GPIO you want for all five pins. Datasheets URLS 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

Wiring Diagram from supplier showing connection to RPI.

Wiring image

This wiring Diagram from the manufacturer showing hardware setup connected to an ~8051 MCU, showing both 3.3 volt and 5 volt systems. Note status of J1 PCB jumper.

Connection image

Software

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. When running Software SPI it may be necessary on very high frequency MCU's to change the LCD_HighFreqDelaySet method, It is a microsecond delay by default it is at 0.

The SPI settings are in LCDSPIon function. Speed is currently at BCM2835_SPI_CLOCK_DIVIDER_64. 6.25MHz on RPI3. This can be adjusted in code or user can pass the divider value in the "begin" method as a parameter. These values are defined by enum bcm2835SPIClockDivider. For full list see link. User can also adjust which SPI chip enable pin the use uing "begin" method parameter.

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 For internal use mostly
3 buffer init Vertical Can be used when initialising at start up
4 drawBitmap() Vertical default, setDrawBitmapAddr(true)
5 drawBitmap() Horizontal setDrawBitmapAddr(false)

See the bitmap example file for more details on each method. Bitmaps can be turned to data here at link , Bitmaps should be defined as const buffers non-const, for methods 3 buffer can be initialised with bitmap data.

User Adjustments

If the LCD does not initialize correctly. Try adjusting the RAM address control setting from 0x02 to 0x01. It can be set in LCDbegin() argument list. See github issue 4 at the Arduino source port github repository for more details, link in overview.

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