See https://github.com/russhughes/s3lcd for a much faster Framebuffered version of the driver using the ESP_LCD esp-idf component. It's a beta release and has minor differences from this driver.

ESP_LCD MicroPython driver for the TTGO T-Display-S3 st7789 display

Warning: This is a work in progress and may contain bugs and/or incorrect documentation.

This driver is based on devbis' st7789_mpy driver. I modified the original driver for one of my projects to add:

• Support for the TTGO T-Dispay-S3 with a parallel interface using the ESP_LCD interface with DMA.
• Display framebuffer enabling alpha blending for many drawing methods.
• Display Rotation.
• Scrolling
• Writing text using bitmaps converted from True Type fonts
• Drawing text using 8 and 16-bit wide bitmap fonts
• Drawing text using Hershey vector fonts
• Drawing JPGs using the TJpgDec - Tiny JPEG Decompressor R0.01d. from http://elm-chan.org/fsw/tjpgd/00index.html
• Drawing PNGs using the pngle library from https://github.com/kikuchan/pngle
• Drawing and rotating Polygons and filled Polygons

Included are 12 bitmap fonts derived from classic pc text mode fonts, 26 Hershey vector fonts and several example programs for different devices.

Pre-compiled firmware

The firmware directory contains pre-compiled MicroPython v1.20.0 firmware compiled using ESP IDF v4.4.4 The firmware includes the st7789 C driver and several frozen python font files. See the README.md file in the fonts folder for more information about the font files.

Thanks go out to:

• https://github.com/devbis for the original driver this is based on.
• https://github.com/hklang10 for letting me know of the new mp_raise_ValueError().
• https://github.com/aleggon for finding the correct offsets for 240x240 displays and for discovering issues compiling STM32 ports.

-- Russ

Overview

This is a driver for MicroPython to handle cheap displays based on the ST7789 chip. The driver is written in C.

Setup MicroPython Build Environment in Ubuntu 20.04.2

See the MicroPython README.md if you run into any build issues not directly related to the st7789 driver. The recommended MicroPython build instructions may have changed.

Update and upgrade Ubuntu using apt-get if you are using a new install of Ubuntu or the Windows Subsystem for Linux.

sudo apt-get -y update
sudo apt-get -y upgrade

Use apt-get to install the required build tools.

sudo apt-get -y install build-essential libffi-dev git pkg-config cmake virtualenv python3-pip python3-virtualenv

Install a compatible esp-idf SDK

The MicroPython README.md states: "The ESP-IDF changes quickly, and MicroPython only supports certain versions. I have had good luck using IDF v4.4.3

Clone the esp-idf SDK repo -- this usually takes several minutes.

git clone -b v4.4.3 --recursive https://github.com/espressif/esp-idf.git
cd esp-idf/
git pull

If you already have a copy of the IDF, you can checkout a version compatible with MicroPython and update the submodules using:

$ cd esp-idf
$ git checkout v4.4.3
$ git submodule update --init --recursive

Install the esp-idf SDK.

./install.sh

Source the esp-idf export.sh script to set the required environment variables. You must source the file and not run it using ./export.sh. You will need to source this file before compiling MicroPython.

source export.sh
cd ..

Clone the MicroPython repo.

git clone https://github.com/micropython/micropython.git

Clone the st7789 driver repo.

git clone https://github.com/russhughes/st7789s3_mpy.git

Update the git submodules and compile the MicroPython cross-compiler

cd micropython/
git submodule update --init
cd mpy-cross/
make
cd ..
cd ports/esp32

Copy any .py files you want to include in the firmware as frozen python modules to the modules subdirectory in ports/esp32. Be aware there is a limit to the flash space available. You will know you have exceeded this limit if you receive an error message saying the code won't fit in the partition or if your firmware continuously reboots with an error.

For example:

cp ../../../st7789s3_mpy/fonts/bitmap/vga1_16x16.py modules
cp ../../../st7789s3_mpy/fonts/truetype/NotoSans_32.py modules
cp ../../../st7789s3_mpy/fonts/vector/scripts.py modules

Build the MicroPython firmware with the driver and frozen .py files in the modules directory. If you did not add any .py files to the modules directory, you can leave out the FROZEN_MANIFEST and FROZEN_MPY_DIR settings.

make USER_C_MODULES=../../../../st7789s3_mpy/st7789/micropython.cmake FROZEN_MANIFEST="" FROZEN_MPY_DIR=$UPYDIR/modules

Erase and flash the firmware to your device. Set PORT= to the ESP32's usb serial port. I could not get the USB serial port to work under the Windows Subsystem (WSL2) for Linux. If you have the same issue, you can copy the firmware.bin file and use the Windows esptool.py to flash your device.

make USER_C_MODULES=../../../../st7789s3_mpy/st7789/micropython.cmake PORT=/dev/ttyUSB0 erase
make USER_C_MODULES=../../../../st7789s3_mpy/st7789/micropython.cmake PORT=/dev/ttyUSB0 deploy

The firmware.bin file will be in the build-GENERIC directory. To flash using the python esptool.py utility. Use pip3 to install the esptool if it's not already installed.

pip3 install esptool

Set PORT= to the ESP32's USB serial port

esptool.py --port COM3 erase_flash
esptool.py --chip esp32 --port COM3 write_flash -z 0x0 firmware.bin

CMake building instructions for MicroPython 1.14 and later

for ESP32:

$ cd micropython/ports/esp32

And then compile the module with specified USER_C_MODULES dir.

$ make USER_C_MODULES=../../../../st7789s3_mpy/st7789/micropython.cmake

Methods

Note: Optional Parameters are shown enclosed in '{' and '}' characters.

• st7789.ST7789(width, height, d7, d6, d5, d4, d3, d2, d1, d0, wr, rd, reset, dc, cs {, backlight, power, rotations, rotation, color_order, inversion, options})

  Required positional arguments:

  • width display width
  • height display height
  • d7: 8-bit data bus pin bit 7 (Most significant bit)
  • d6: 8-bit data bus pin bit 6
  • d5: 8-bit data bus pin bit 5
  • d4: 8-bit data bus pin bit 4
  • d3: 8-bit data bus pin bit 3
  • d2: 8-bit data bus pin bit 2
  • d1: 8-bit data bus pin bit 1
  • d0: 8-bit data bus pin bit 0 (Least significant bit)
  • wr: write strobe pin
  • rd: read strobe pin
  • reset sets the pin connected to the display's hardware reset
  • dc sets the pin connected to the display data/command selection input.
  • cs sets the pin connected to the displays chip select input.

  Optional keyworld arguments:

  • backlight sets the pin connected to the display's backlight enable input. The display's backlight input can often be left floating or disconnected as the backlight on some displays is always powered on and cannot be turned off.

  • power sets the pin connected to the display's power enable input.

  • rotations sets the orientation table. The orientation table is a list of tuples for each rotation used to set the width, height, x_gap, y_gap, swap_xy, mirror_x, and mirror_y values.

    Default rotations are included for the following st7789 and st7735 display sizes:

    Display	Default Orientation Tables
    240x320	[(240, 320, 0, 0, false, false, false), (320, 240, 0, 0, true, true, false), (240, 320, 0, 0, false, true, true), (320, 240, 0, 0, true, false, true)]
    170x320	[(170, 320, 35, 0, false, false, false), (320, 170, 0, 35, true, true, false), (170, 320, 35, 0, false, true, true), (320, 170, 0, 35, true, false, true)]
    240x240	[(240, 240, 0, 0, false, false, false), (240, 240, 0, 0, true, true, false), (240, 240, 0, 80, false, true, true), (240, 240, 80, 0, true, false, true)]
    135x240	[(135, 240, 52, 40, false, false, false), (240, 135, 40, 53, true, true, false), (135, 240, 53, 40, false, true, true), (240, 135, 40, 52, true, false, true)]
    128x160	[(128, 160, 0, 0, false, false, false), (160, 128, 0, 0, true, true, false), (128, 160, 0, 0, false, true, true), (160, 128, 0, 0, true, false, true)]
    128x128	[(128, 128, 2, 1, false, false, false), (128, 128, 1, 2, true, true, false), (128, 128, 2, 3, false, true, true), {128, 128, 3, 2, true, false, true)]

    You may define up to 4 rotations.

  • rotation sets the display rotation according to the orientation table.

    The default orientation table defines four counter-clockwise rotations for 240x320, 240x240, 134x240, 128x160 and 128x128 displays with the LCD's ribbon cable at the bottom of the display. The default rotation is Portrait (0 degrees).

    Index	Rotation
    0	Portrait (0 degrees)
    1	Landscape (90 degrees)
    2	Reverse Portrait (180 degrees)
    3	Reverse Landscape (270 degrees)

  • color_order sets the color order used by the driver (st7789.RGB or st7789.BGR)

  • inversion Sets the display color inversion mode if True, clears the display color inversion mode if false.

  • options Sets driver option flags.

    Option	Description
    st7789.WRAP	pixels, lines, polygons, and Hershey text will wrap around the display both horizontally and vertically.
    st7789.WRAP_H	pixels, lines, polygons, and Hershey text will wrap around the display horizontally.
    st7789.WRAP_V	pixels, lines, polygons, and Hershey text will wrap around the display vertically.

• deinit()

  Frees memory used by buffers and deletes the dedicated GPIO bundle. This method should be called before reinitalizing the display without hard resetting the microcontroller.

• show({wait})

  Update the display from the framebuffer. If the optional wait parameter is True, this method blocks until the display refresh is complete. You must use show() method to update the display before you will see anything on the display.

• inversion_mode(bool) Sets the display color inversion mode if True, clears the display color inversion mode if False.

• init()

  Must be called to initialize the display.

• on()

  Turn on the backlight pin if one was defined during init.

• off()

  Turn off the backlight pin if one was defined during init.

• fill({color, alpha})

  Fill the display with the specified color optionally alpha blended with the background. color defaults to BLACK, alpha defaults to 255.

• pixel(x, y {, color, alpha})

  Set the specified pixel to the given color. color defaults to WHITE, alpha defaults to 255.

• line(x0, y0, x1, y1 {, color, aplha})

  Draws a single line with the provided color from (x0, y0) to (x1, y1). color defaults to BLACK, alpha defaults to 255.

• hline(x, y, w {, color, alpha})

  Draws a single horizontal line with the provided color and length in pixels. color defaults to BLACK, alpha defaults to 255.

• vline(x, y, length {, color, alpha})

  Draws a single horizontal line with the provided color and length in pixels. color defaults to BLACK, alpha defaults to 255.

• rect(x, y, width, height {, color, alpha})

  Draws a rectangle from (x, y) with corresponding dimensions. color defaults to BLACK, alpha defaults to 255.

• fill_rect(x, y, width, height {, color, alpha})

  Fill rectangle width by height starting at x, y with color optionally alpha blended with the background. color defaults to BLACK, alpha defaults to 255.

• circle(x, y, r {, color, alpha})

  Draws a circle with radius r centered at the (x, y) coordinates in the given color. color defaults to BLACK, alpha defaults to 255.

• fill_circle(x, y, r {, color, alpha})

  Draws a filled circle with radius r centered at the (x, y) coordinates in the given color. color defaults to BLACK, alpha defaults to 255.

• blit_buffer(buffer, x, y, width, height {, alpha})

  Copy bytes() or bytearray() content to the screen internal memory. Note: every color requires 2 bytes in the array. alpha defaults to 255.

• text(font, s, x, y {, fg, bg, alpha})

  Write text to the display using the specified bitmap font with the coordinates as the upper-left corner of the text. The optional arguments fg and bg can set the foreground and background colors of the text; otherwise the foreground color defaults to WHITE, and the background color defaults to BLACK. alpha defaults to 255. See the README.md in the fonts/bitmap directory for example fonts.

• write(bitmap_font, s, x, y {, fg, bg, alpha})

  Write text to the display using the specified proportional or Monospace bitmap font module with the coordinates as the upper-left corner of the text. The foreground and background colors of the text can be set by the optional arguments fg and bg, otherwise the foreground color defaults to WHITE and the background color defaults to BLACK. alpha defaults to 255.

  See the README.md in the truetype/fonts directory for example fonts. Returns the width of the string as printed in pixels. Accepts UTF8 encoded strings.

  The font2bitmap utility creates compatible 1 bit per pixel bitmap modules from Proportional or Monospaced True Type fonts. The character size, foreground, background colors, and characters in the bitmap module may be specified as parameters. Use the -h option for details. If you specify a buffer_size during the display initialization, it must be large enough to hold the widest character (HEIGHT * MAX_WIDTH * 2).

• write_len(bitap_font, s)

  Returns the string's width in pixels if printed in the specified font.

• draw(vector_font, s, x, y {, fg, scale, alpha})

  Draw text to the display using the specified Hershey vector font with the coordinates as the lower-left corner of the text. The foreground color of the text can be set by the optional argument fg. Otherwise the foreground color defaults to WHITE. The size of the text can be scaled by specifying a scale value. The scale value must be larger than 0 and can be a floating-point or an integer value. The scale value defaults to 1.0. alpha defaults to 255. See the README.md in the vector/fonts directory, for example fonts and the utils directory for a font conversion program.

• draw_len(vector_font, s {, scale})

  Returns the string's width in pixels if drawn with the specified font.

• jpg(jpg_filename, x, y)

  Draw a JPG file on the display at the given x and y coordinates as the upper left corner of the image. This method requires an additional 3100 bytes of memory for it's work buffer.

• jpg_decode(jpg_filename {, x, y, width, height})

  Decode a jpg file and return it or a portion of it as a tuple composed of (buffer, width, height). The buffer is a color565 blit_buffer compatible byte array. The buffer will require width * height * 2 bytes of memory.

  If the optional x, y, width, and height parameters are given, the buffer will only contain the specified area of the image. See examples/T-DISPLAY/clock/clock.py and examples/T-DISPLAY/toasters_jpg/toasters_jpg.py for examples.

• png(png_filename, x, y)

  Draw a PNG file on the display with upper left corner of the image at the given x and y coordinates. The PNG will not be clipped it must be able to fit fully on the display or it will not be drawn. Transparency is supported, see the alien.py program in the examples/png folder for an example.

• polygon_center(polygon)

  Return the center of the polygon as an (x, y) tuple. The polygon should consist of a list of (x, y) tuples forming a closed convex polygon.

• fill_polygon(polygon, x, y, color {, alpha, angle, center_x, center_y})

  Draw a filled polygon at the x, and y coordinates in the color given. alpha defaults to 255. The polygon may be rotated angle radians about the center_x and center_y point. The polygon should consist of a list of (x, y) tuples forming a closed convex polygon.

  See the TWATCH-2020 watch.py demo for an example.

• polygon(polygon, x, y, color {, alpha, angle, center_x, center_y)

  Draw a polygon at the x, and y coordinates in the color given. alpha defaults to 255. The polygon may be rotated angle radians about the center_x and center_y point. The polygon should consist of a list of (x, y) tuples forming a closed convex polygon.

  See the T-Display roids.py for an example.

• bitmap(bitmap, x , y {, alpha, index}) or bitmap((bitmap_as_bytes, w, h), x , y {, alpha})

  Draw a bitmap using the specified x, y coordinates as the upper-left corner of the bitmap.

  • If the bitmap parameter is a bitmap module, the index parameter may be specified to select a specific bitmap from the module. The index parameter must be an integer value greater than or equal to 0 and less than the number of bitmaps in the module. The index value defaults to 0. alpha defaults to 255.

  • If the bitmap_module parameter is a tuple, the tuple must contain a bitmap as a byte array, the width of the bitmap in pixels, and the height of the bitmap in pixels. alpha defaults to 255.

  The imgtobitmap.py utility creates compatible 1 to 8 bit per pixel bitmap modules from image files using the Pillow Python Imaging Library.

  The monofont2bitmap.py utility creates compatible 1 to 8 bit per pixel bitmap modules from Monospaced True Type fonts. See the inconsolata_16.py, inconsolata_32.py and inconsolata_64.py files in the examples/lib folder for sample modules and the mono_font.py program for an example using the generated modules.

  The character sizes, bit per pixel, foreground, background colors, and the characters to include in the bitmap module may be specified as parameters. Use the -h option for details. Bits per pixel settings larger than one may be used to create antialiased characters at the expense of memory use.

• width()

  Returns the current logical width of the display. (ie a 135x240 display rotated 90 degrees is 240 pixels wide)

• height()

  Returns the current logical height of the display. (ie a 135x240 display rotated 90 degrees is 135 pixels high)

• rotation(r)

  Set the rotates the logical display in a counter-clockwise direction. 0-Portrait (0 degrees), 1-Landscape (90 degrees), 2-Inverse Portrait (180 degrees), 3-Inverse Landscape (270 degrees)

The module exposes predefined colors: BLACK, BLUE, RED, GREEN, CYAN, MAGENTA, YELLOW, and WHITE

Scrolling

The st7789 display controller contains a 240 by 320-pixel frame buffer used to store the pixels for the display. For scrolling, the frame buffer consists of three separate areas; The (tfa) top fixed area, the (height) scrolling area, and the (bfa) bottom fixed area. The tfa is the upper portion of the frame buffer in pixels not to scroll. The height is the center portion of the frame buffer in pixels to scroll. The bfa is the lower portion of the frame buffer in pixels not to scroll. These values control the ability to scroll the entire or a part of the display.

For displays that are 320 pixels high, setting the tfa to 0, height to 320, and bfa to 0 will allow scrolling of the entire display. You can set the tfa and bfa to a non-zero value to scroll a portion of the display. tfa + height + bfa = should equal 320, otherwise the scrolling mode is undefined.

Displays less than 320 pixels high, the tfa, height, and bfa will need to be adjusted to compensate for the smaller LCD panel. The actual values will vary depending on the configuration of the LCD panel. For example, scrolling the entire 135x240 TTGO T-Display requires a tfa value of 40, height value of 240, and bfa value of 40 (40+240+40=320) because the T-Display LCD shows 240 rows starting at the 40th row of the frame buffer, leaving the last 40 rows of the frame buffer undisplayed.

Other displays like the Waveshare Pico LCD 1.3 inch 240x240 display require the tfa set to 0, height set to 240, and bfa set to 80 (0+240+80=320) to scroll the entire display. The Pico LCD 1.3 shows 240 rows starting at the 0th row of the frame buffer, leaving the last 80 rows of the frame buffer undisplayed.

The vscsad method sets the (VSSA) Vertical Scroll Start Address. The VSSA sets the line in the frame buffer that will be the first line after the tfa.

The ST7789 datasheet warns:

The value of the vertical scrolling start address is absolute (with reference to the frame memory),
it must not enter the fixed area (defined by Vertical Scrolling Definition, otherwise undesirable
image will be displayed on the panel.

• vscrdef(tfa, height, bfa) Set the vertical scrolling parameters.

  tfa is the top fixed area in pixels. The top fixed area is the upper portion of the display frame buffer that will not be scrolled.

  height is the total height in pixels of the area scrolled.

  bfa is the bottom fixed area in pixels. The bottom fixed area is the lower portion of the display frame buffer that will not be scrolled.

• vscsad(vssa) Set the vertical scroll address.

  vssa is the vertical scroll start address in pixels. The vertical scroll start address is the line in the frame buffer will be the first line shown after the TFA.

Helper functions

• color565(r, g, b)

  Pack a color into 2-bytes rgb565 format

• map_bitarray_to_rgb565(bitarray, buffer, width {, color, bg_color})

  Convert a bitarray to the rgb565 color buffer suitable for blitting. Bit 1 in bitarray is a pixel with color and 0 - with bg_color.