ucg Module

Since	Origin / Contributor	Maintainer	Source
2015-08-05	Oli Kraus, Arnim Läuger	Arnim Läuger	ucglib

Ucglib is a graphics library developed at olikraus/ucglib with support for color TFT displays.

!!! note "BSD License for Ucglib Code" Universal 8bit Graphics Library (http://code.google.com/p/u8glib/)

Copyright (c) 2014, olikraus@gmail.com
All rights reserved.

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are permitted provided that the following conditions are met:

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  of conditions and the following disclaimer.

* Redistributions in binary form must reproduce the above copyright notice, this
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The NodeMCU firmware supports a subset of these:

HX8352C
ILI9163
ILI9341
ILI9486
PCF8833
SEPS225
SSD1331
SSD1351
ST7735

This integration is based on version 1.5.2.

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.

Display selection

HW SPI based displays with support in u8g2 can be enabled.

The procedure is different for ESP8266 and ESP32 platforms.

ESP8266

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) \

ESP32

Enable the desired entries for SPI displays in ucg's sub-menu (run make menuconfig).

Fonts

ucglib comes with a wide range of fonts for small displays. Since they need to be compiled into the firmware image.

The procedure is different for ESP8266 and ESP32 platforms.

ESP8266

Add the desired fonts to the font table in app/include/ucg_config.h:

#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 will be available as ucg.<font_name> in Lua.

ESP32

Add the desired fonts to the font selection sub-entry via make menuconfig.

Display Drivers

Initialize a display via Hardware SPI.

hx8352c_18x240x400_hw_spi()
ili9163_18x128x128_hw_spi()
ili9341_18x240x320_hw_spi()
ili9486_18x320x480_hw_spi()
pcf8833_16x132x132_hw_spi()
seps225_16x128x128_uvis_hw_spi()
ssd1351_18x128x128_hw_spi()
ssd1351_18x128x128_ft_hw_spi()
ssd1331_18x96x64_uvis_hw_spi()
st7735_18x128x160_hw_spi()

Syntax

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

Parameters

bus SPI master bus
cs GPIO pin for /CS
dc GPIO pin for DC
res GPIO pin for /RES, none if omitted

Returns

ucg display object

Example for ESP8266

-- Hardware SPI CLK  = GPIO14
-- Hardware SPI MOSI = GPIO13
-- Hardware SPI MISO = GPIO12 (not used)
-- Hardware SPI /CS  = GPIO15 (not used)
cs  = 8 -- GPIO15, pull-down 10k to GND
dc  = 4 -- GPIO2
res = 0 -- GPIO16, RES is optional YMMV
bus = 1
spi.setup(bus, spi.MASTER, spi.CPOL_LOW, spi.CPHA_LOW, spi.DATABITS_8, 0)
-- we won't be using the HSPI /CS line, so disable it again
gpio.mode(8, gpio.INPUT, gpio.PULLUP)

disp = ucg.st7735_18x128x160_hw_spi(bus, cs, dc, res)

Example for ESP32

sclk = 19
mosi = 23
cs   = 22
dc   = 16
res  = 17
bus = spi.master(spi.HSPI, {sclk=sclk, mosi=mosi})
disp = ucg.st7735_18x128x160_hw_spi(bus, 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, ...