chrisdepas / st7735r

A fast low level Arduino Uno compatible graphics library for the 160x128 pixel 16-bit color TFT LCD display that uses the ST7735R chip.

Fork of https://github.com/juj/ST7735R

Changes Overview

• Shortened function names
• Allow defining pins etc from arduino, before #include
• Consolidated into single file
• Removed SDCard stuff
• Added Display_Clear(r, g, b) (Sets the entire screen to a single color)
• Added ST7735R_MIN_X, ST7735R_MIN_Y, ST7735R_MAX_X, ST7735R_MAX_Y (Helper definitions for valid x,y ranges)

Name Changes

Old	New
(None)	DisplayClear
ST7735R_BEGIN_TRANSACTION	DisplayBeginTransaction
ST7735R_END_TRANSACTION	DisplayEndTransaction
ST7735R_SendCommandList	DisplaySendCommandList
ST7735R_Begin	DisplayBegin
ST7735R_Line	DisplayLine
ST7735R_DrawMonoSprite	DisplayDrawMonoSprite
ST7735R_SendCommandList	DisplaySendCommandList
ST7735R_BeginRect	DisplayBeginRect
ST7735R_PushPixel	DisplayPushPixel
ST7735R_EndDraw	DisplayEndDraw
ST7735R_BeginPixels	DisplayBeginPixels
ST7735R_Pixel	DisplayPixel
ST7735R_PushPixel_U16	DisplayPushPixel_U16
ST7735R_FillRect	DisplayFillRect
ST7735R_Circle	DisplayCircle
ST7735R_DrawText	DisplayDrawText
ST7735R_FilledCircle	DisplayFilledCircle
ST7735R_DrawMonoSprite	DisplayDrawMonoSprite
SDCard_GetFileStartingBlock	Removed
ST7735R_Draw565	Removed
ST7735R_DrawBMP	Removed
LoadBMPImage	Removed

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Original Readme (Without test related info):

This repository contains a fast low level Arduino Uno compatible graphics library for the 160x128 pixel 16-bit color TFT LCD display that uses the ST7735R chip. It was written as a programming exercise after realizing that the built-in "Adafruit" TFT library that Arduino ships with is very slow. I wanted to display some slideshow images on the TFT using an Arduino, but unfortunately the built-in libraries take about 2.9 seconds(!) to draw a single 160x128 image on the screen from the SD card. With this library, it is possible to draw an image in about 188 milliseconds, which is a considerable 15.2x performance increase! The aim of this code is to squeeze every individual clock cycle out of the drawing routines to see how fast it is possible to drive the ST7735R display. If you can improve the code here, please let me know.

Rendering features

This library offers (almost) drop-in replacements for most built-in TFT library methods, and comes with the following functions:

• Draw batches of individual pixels with a sequence of ST7735R_BeginPixels(), ST7735R_Pixel() and ST7735R_EndDraw() functions.
• Fill solid rectangles with the ST7735R_FillRect() function.
• Stream rectangles of custom content with a sequence of ST7735R_BeginRect(), ST7735R_PushPixel() and ST7735R_EndDraw() functions.
• Draw horizontal lines with the function ST7735R_HLine() and vertical lines with the function ST7735R_VLine().
• Draw arbitrary sloped lines with the function ST7735R_Line().
• Draw hollow circles with the function ST7735R_Circle().
• Draw filled circles with the function ST7735R_FilledCircle().
• Draw 1-bit monochrome sprites from PROGMEM with the function ST7735R_DrawMonoSprite().
• Draw text stored in PROGMEM with the function ST7735R_DrawText(). One font file "monaco_font.h" is provided, create more with the ttffont_to_cppheader.py tool.
• Draw 24-bit bottom-up .bmp images with the functions LoadBMPImage(), SDCard_GetFileStartingBlock() and ST7735R_DrawBMP(). (requires hacking of the built-in SD card library to enable raw FAT32 block streaming).
• Draw pre-prepared raw 16-bit images (files formatted with suffix .565) with the functions SDCard_GetFileStartingBlock() and ST7735R_Draw565(). (requires hacking of the built-in SD card library to enable raw FAT32 block streaming). Use the python tool image_to_rgb565.py to convert images to this format.

The library has only been used on an Arduino Uno with 8MHz hardware SPI mode, and contains several assumptions that might not hold when transferring the configuration to other setups. Don't use blindly without understanding the internals of the code!

References

• The display: http://www.arduino.cc/en/Guide/TFT (bought from http://www.verkkokauppa.com/fi/product/30873/dsgrv/Arduino-1-77-TFT-LCD-Screen-naytto-Arduino-kehitysalustoille)
• Wiring instructions at http://www.arduino.cc/en/Guide/TFTtoBoards
• Data sheet at http://www.adafruit.com/datasheets/ST7735R_V0.2.pdf
• Atmel AVR 8 bit instruction set documentation: http://www.atmel.com/images/doc0856.pdf
• Requires manual pin to port+bit mapping configuration. This is useful: http://pighixxx.com/unov3pdf.pdf

License and Usage

Unless otherwise stated in individual files, all code is released to public domain. Do whatever you wish with it. This repository is a result of some recreational hacking activity, rather than a mission to build a stable and maintained library, so expect the maturity to be as such.