- Name: ST7735
- Description: Library for TFT SPI LCD, ST7735 Driver.
- Author: Gavin Lyons
- STM32: STM32F070RB nucleo-64
- Toolchain: STM32cubeIDE, HAL, C.
- Note: this is a fork of PIC project at link
These two are the only type of ST7735 library tested on, but should work on other types in theory.
- TFT SPI LCD, ST7735 Driver, Red PCB v1.1, 1.44 , 128 x 128 pixels, "ST7735R Red Tab"
- TFT SPI LCD, ST7735 Driver, Red PCB v1.2, 1.8 , 128 x 160 pixels, "ST7735S Black Tab"
No support for built-in SD card holder (that some modules have) at present and backlight control is left to user.
In the setup() function in USER OPTION 1 Screen Setup. Select your PCB size and offsets. User can adjust pixel height, pixel width and screen offsets in the header file. When calling function TFTInitScreenSize(OFFSET_COL, OFFSET_ROW , TFT_PIXEL_WIDTH , TFT_PIXEL_HEIGHT).
There are 4 types of the ST7735 TFT display supported.. User picks the one they want when calling TFTInitPCBType() function See USER OPTION 2 PCB_TYPE in Setup() function in main.c
| Number | Description | Enum label |
|---|---|---|
| 1 | ST7735B controller | TFT_ST7735B |
| 2 | ST7735R Green Tab | TFT_ST7735R_Green |
| 3 | ST7735R Red Tab | TFT_ST7735R_Red |
| 4 | ST7735S Black Tab | TFT_ST7735S_Black |
12 fonts are included. Font data table:
| num | enum name | Char size XbyY | ASCII range | Size bytes | Size Scale-able |
|---|---|---|---|---|---|
| 1 | $_Default | 5x8 | 0x20-0x7E, | 470 | Y |
| 2 | $_Thick | 7x8 | 0x20-0x5A, no lowercase letters | 406 | Y |
| 3 | $_SevenSeg | 4x8 | 0x20-0x7A | 360 | Y |
| 4 | $_Wide | 8x8 | 0x20-0x5A, no lowercase letters | 464 | Y |
| 5 | $_Tiny | 3x8 | 0x20-0x7E | 285 | Y |
| 6 | $_Homespun | 7x8 | 0x20-0x7E | 658 | Y |
| 7 | $_Bignum | 16x32 | 0x2D-0x3A ,0-10 - . / : | 896 | N |
| 8 | $_Mednum | 16x16 | 0x2D-0x3A ,0-10 - . / : | 448 | N |
| 9 | $_ArialRound | 16x24 | 0x20-0x7E | 4608 | N |
| 10 | $_ArialBold | 16x16 | 0x20-0x7E | 3072 | N |
| 11 | $_Mia | 8x16 | 0x20-0x7E | 1520 | N |
| 12 | $_Dedica | 6x12 | 0x20-0x7E | 1152 | N |
- $ = TFTFont
- Fonts 1-6 are byte high(at text size 1) scale-able fonts, columns of padding added by SW.
- Font 7-8 are large numerical fonts and cannot be scaled(just one size). All fonts are optional and can be removed from program by commenting out the relevant TFT_Font define in the ST7735_TFT_Font.h file Turn off unused fonts to save memory.
Font Methods:
| Font num | Method | Size parameter | Notes |
|---|---|---|---|
| 1-6 | drawChar | Y | draws single character |
| 1-6 | drawText | Y | draws character array |
| 7-12 | drawChar2 | N | draws single character |
| 7-12 | drawText2 | N | draws character array |
| 1-12 | TFTprint | ~ | Polymorphic, prints many types of data using vsprint |
The TFTprint method included uses vsprint to print numerical data. In order to use floating point numbers you need to add -u _printf_float to project properties , C build , settings , MCU Gcc Linker , misc , other flags section.
These functions return a number in event of an error, such as wrong font chosen , ASCII character outside chosen fonts range, character out of screen bounds and invalid character array pointer object.
This library supports both Hardware SPI and software SPI. Change the define a top of header file to switch between the two. USER OPTION 4 SPI TYPE.
The Main.c contains tests showing library functions There is an TFT library (ST7735_TFT.c and ST7735_TFT.h), There are font files that contains ASCII pixel fonts. There are bitmap data files that contain the bitmap test data used by the main.c to test functions
| Num | Function Name | Note |
|---|---|---|
| 1 | TFTfillRectangle | --- |
| 2 | TFTfillRect | uses TFTdrawFastVLine |
| 3 | TFTfillRectangleBuffer | Uses buffered writes , ~5 times faster than #1 & #2 |
| 4 | TFTfillScreen | Wraps #1 |
| 5 | TFTfillScreenBuffer | Wraps #3 |
There are 4 functions to support drawing bitmaps. Full color bitmaps will take up a lot of memory on this device. In the bitmap data file you can switch off the tests in USER OPTION 5.
| Num | Function Name | Colour support | bitmap size Max | Note |
|---|---|---|---|---|
| 1 | Icon | bi-colour | (8 x (0-Max_y)) | useful to create icons or fill rows with patterns ,Data vertically addressed |
| 2 | Bitmap | bi-colour | 2048 bytes | Data horizontally addressed |
| 3 | BitmapBuffer | bi-colour | 2048 bytes | Data horizontally addressed , uses buffered writes , 25 times faster than #2 |
| 4 | Bitmap1624Buffer | 16 bit or 24 bit color | 32768 or 49152 | Data from Array 24 bit Converted by software to 16-bit color, uses buffered writes |
- Bitmap size in kiloBytes = (screenWidth * screenHeight * bitsPerPixel)/(1024 * 8)
- Math in bitmap size column 2-4 assumes 128x128 pixel screen.
- The data array for 1 -3 is created from image files using file data conversion tool link
- The data array for 4 is created from BMP files using file data conversion tool link
| TFT PinNum | Pindesc | STM32 SW SPI | STM32 HW SPI |
|---|---|---|---|
| 1 | LED | VCC | VCC |
| 2 | SCLK | PA1 | PB3 SPI1_SCK |
| 3 | SDA | PA0 | PA7 SPI1_MOSI |
| 4 | A0/DC | PC1 | PC1 |
| 5 | RESET | PC0 | PC0 |
| 6 | SS/CS | PC2 | PC2 |
| 7 | GND | GND | GND |
| 8 | VCC | VCC | VCC |
- NOTE connect LED backlight pin 1 thru a 150R to 220R ohm resistor to 3.3V or 5V VCC.
- This is a 3.3V logic device do NOT connect the I/O logic lines to 5V.
- You can connect VCC to 5V if there is a 3.3 volt regulator on back of TFT module.
Output of some of the test routine's on a 128x128 TFT.
- Different defined colors at default font size 1. Full 16 bit colour 565 available
- Different sizes of default font: 2,3,4 & 5 . fonts 1-6 are scale-able
- Different Fonts at font size 2, Fonts 1-5 . font 6-12 not shown here.
- Shapes.
- MORE shapes!
- Bitmap (bi-color) A background and a foreground.
- 16 bit color bitmap 128x128 image included in test data
- 24 bit color bitmap 64x64 image included in test data
Timer16 and Usart are included just for the Frames per second test, TestFPS. The FPS(frame per second) test is enabled by a boolean variable flag in main.c