ucg Module

Ucglib is a graphics library developed at olikraus/ucglib with support for color TFT displays. The NodeMCU firmware supports a subset of these:

  • ILI9163
  • ILI9341
  • PCF8833
  • SEPS225
  • SSD1331
  • SSD1351
  • ST7735

This integration is based on v1.3.3.

Overview

SPI Connection

The HSPI module is used (more information), so certain pins are fixed:

  • HSPI CLK = GPIO14
  • HSPI MOSI = GPIO13
  • HSPI MISO = GPIO12 (not used)

All other pins can be assigned to any available GPIO:

  • CS
  • D/C
  • RES (optional for some displays)

Also refer to the initialization sequence eg in GraphicsTest.lua:

spi.setup(1, spi.MASTER, spi.CPOL_LOW, spi.CPHA_LOW, 8, 8)

Library Usage

The Lua bindings for this library closely follow ucglib's object oriented C++ API. Based on the ucg class, you create an object for your display type.

ILI9341 via SPI:

cs  = 8 -- GPIO15, pull-down 10k to GND
dc  = 4 -- GPIO2
res = 0 -- GPIO16, RES is optional YMMV
disp = ucg.ili9341_18x240x320_hw_spi(cs, dc, res)

This object provides all of ucglib's methods to control the display. Again, refer to GraphicsTest.lua to get an impression how this is achieved with Lua code. Visit the ucglib homepage for technical details.

Displays

To get access to the display constructors, add the desired entries to the display table in app/include/ucg_config.h:

#define UCG_DISPLAY_TABLE                          \
    UCG_DISPLAY_TABLE_ENTRY(ili9341_18x240x320_hw_spi, ucg_dev_ili9341_18x240x320, ucg_ext_ili9341_18) \
    UCG_DISPLAY_TABLE_ENTRY(st7735_18x128x160_hw_spi, ucg_dev_st7735_18x128x160, ucg_ext_st7735_18) \

Fonts

ucglib comes with a wide range of fonts for small displays. Since they need to be compiled into the firmware image, you'd need to include them in app/include/ucg_config.h and recompile. Simply add the desired fonts to the font table:

#define UCG_FONT_TABLE                              \
    UCG_FONT_TABLE_ENTRY(font_7x13B_tr)             \
    UCG_FONT_TABLE_ENTRY(font_helvB12_hr)           \
    UCG_FONT_TABLE_ENTRY(font_helvB18_hr)           \
    UCG_FONT_TABLE_ENTRY(font_ncenR12_tr)           \
    UCG_FONT_TABLE_ENTRY(font_ncenR14_hr)

They'll be available as ucg.<font_name> in Lua.

Display Drivers

Initialize a display via Hardware SPI.

  • ili9163_18x128x128_hw_spi()
  • ili9341_18x240x320_hw_spi()
  • pcf8833_16x132x132_hw_spi()
  • seps225_16x128x128_univision_hw_spi()
  • ssd1351_18x128x128_hw_spi()
  • ssd1351_18x128x128_ft_hw_spi()
  • ssd1331_18x96x64_univision_hw_spi()
  • st7735_18x128x160_hw_spi()

Syntax

ucg.st7735_18x128x160_hw_spi(cs, dc[, res])

Parameters

  • cs GPIO pin for /CS
  • dc GPIO pin for DC
  • res GPIO pin for /RES (optional)

Returns

ucg display object

Example

spi.setup(1, spi.MASTER, spi.CPOL_LOW, spi.CPHA_LOW, spi.DATABITS_8, 0)

cs  = 8 -- GPIO15, pull-down 10k to GND
dc  = 4 -- GPIO2
res = 0 -- GPIO16, RES is optional YMMV
disp = ucg.st7735_18x128x160_hw_spi(cs, dc, res)

Constants

Constants for various functions.

ucg.FONT_MODE_TRANSPARENT, ucg.FONT_MODE_SOLID, ucg.DRAW_UPPER_RIGHT, ucg.DRAW_UPPER_LEFT, ucg.DRAW_LOWER_RIGHT, ucg.DRAW_LOWER_LEFT, ucg.DRAW_ALL

ucg.font_7x13B_tr, ...

ucg.disp Sub-Module

ucg.disp:begin()

See ucglib begin().

ucg.disp:clearScreen()

See ucglib clearScreen().

ucg.disp:draw90Line()

See ucglib draw90Line().

ucg.disp:drawBox()

See ucglib drawBox().

ucg.disp:drawCircle()

See ucglib drawCircle().

ucg.disp:drawDisc()

See ucglib drawDisc().

ucg.disp:drawFrame()

See ucglib drawFrame().

ucg.disp:drawGlyph()

See ucglib drawGlyph().

ucg.disp:drawGradientBox()

See ucglib drawGradientBox().

ucg.disp:drawGradientLine()

See ucglib drawGradientLine().

ucg.disp:drawHLine()

See ucglib drawHLine().

ucg.disp:drawLine()

See ucglib drawLine().

ucg.disp:drawPixel()

See ucglib drawPixel().

ucg.disp:drawRBox()

See ucglib drawRBox().

ucg.disp:drawRFrame()

See ucglib drawRFrame().

ucg.disp:drawString()

See ucglib drawString().

ucg.disp:drawTetragon()

See ucglib drawTetragon().

ucg.disp:drawTriangle()

See ucglib drawTriangle().

ucg.disp:drawVLine()

See ucglib drawVline().

ucg.disp:getFontAscent()

See ucglib getFontAscent().

ucg.disp:getFontDescent()

See ucglib getFontDescent().

ucg.disp:getHeight()

See ucglib getHeight().

ucg.disp:getStrWidth()

See ucglib getStrWidth().

ucg.disp:getWidth()

See ucglib getWidth().

ucg.disp:print()

See ucglib print().

ucg.disp:setClipRange()

See ucglib setClipRange().

ucg.disp:setColor()

See ucglib setColor().

ucg.disp:setFont()

ucglib comes with a wide range of fonts for small displays. Since they need to be compiled into the firmware image, you'd need to include them in app/include/ucg_config.h and recompile. Simply add the desired fonts to the font table:

#define UCG_FONT_TABLE                              \
    UCG_FONT_TABLE_ENTRY(font_7x13B_tr)             \
    UCG_FONT_TABLE_ENTRY(font_helvB12_hr)           \
    UCG_FONT_TABLE_ENTRY(font_helvB18_hr)           \
    UCG_FONT_TABLE_ENTRY(font_ncenR12_tr)           \
    UCG_FONT_TABLE_ENTRY(font_ncenR14_hr)

They'll be available as ucg.<font_name> in Lua.

Syntax

disp:setFont(font)

Parameters

font constant to identify pre-compiled font

Returns

nil

Example

disp:setFont(ucg.font_7x13B_tr)

See also

ucglib setFont()

ucg.disp:setFontMode()

See ucglib setFontMode().

ucg.disp:setFontPosBaseline()

See ucglib setFontPosBaseline().

ucg.disp:setFontPosBottom()

See ucglib setFontPosBottom().

ucg.disp:setFontPosCenter()

See ucglib setFontPosCenter().

ucg.disp:setFontPosTop()

See ucglib setFontPosTop().

ucg.disp:setMaxClipRange()

See ucglib setMaxClipRange().

ucg.disp:setPrintDir()

See ucglib setPrintDir().

ucg.disp:setPrintPos()

See ucglib setPrintPos().

ucg.disp:setRotate90()

See ucglib setRotate90().

ucg.disp:setRotate180()

See ucglib setRotate180().

ucg.disp:setRotate270()

See ucglib setRotate270().

ucg.disp:setScale2x2()

See ucglib setScale2x2().

ucg.disp:undoClipRange()

See ucglib undoClipRange().

ucg.disp:undoRotate()

See ucglib undoRotate().

ucg.disp:undoScale()

See ucglib undoScale().