kopia lustrzana https://github.com/devbis/st7789_mpy
180 wiersze
4.8 KiB
Markdown
180 wiersze
4.8 KiB
Markdown
ST7789 Driver for MicroPython
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=============================
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Overview
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--------
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This is a driver for MicroPython to handle cheap displays
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based on ST7789 chip.
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<p align="center">
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<img src="https://raw.githubusercontent.com/devbis/st7789_mpy/master/docs/ST7789.jpg" alt="ST7789 display photo"/>
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</p>
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It is written in pure C, so you have to build
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firmware by yourself.
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Only ESP8266 and ESP32 are supported for now.
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Building instruction
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---------------------
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Prepare build tools as described in the manual.
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You should follow the instruction for building MicroPython and
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ensure that you can build the firmware without this display module.
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Clone this module alongside the MPY sources:
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$ git clone https://github.com/devbis/st7789_mpy.git
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Go to MicroPython ports directory and for ESP8266 run:
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$ cd micropython/ports/esp8266
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for ESP32:
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$ cd micropython/ports/esp32
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And then compile the module with specified USER_C_MODULES dir
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$ make USER_C_MODULES=../../../st7789_mpy/ all
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If you have other user modules, copy the st7789_driver/st7789 to
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the user modules directory
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Upload the resulting firmware to your MCU as usual with esptool.py
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(See
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[MicroPython docs](http://docs.micropython.org/en/latest/esp8266/tutorial/intro.html#deploying-the-firmware)
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for more info)
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Working examples
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----------------
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This module was tested on ESP32 and ESP8266 MCUs.
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You have to provide `machine.SPI` object and at least two pins for RESET and
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DC pins on the screen for the display object.
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# ESP 8266
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import machine
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import st7789
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spi = machine.SPI(1, baudrate=40000000, polarity=1)
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display = st7789.ST7789(spi, 240, 240, reset=machine.Pin(5, machine.Pin.OUT), dc=machine.Pin(4, machine.Pin.OUT))
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For ESP32 modules you have to provide specific pins for SPI.
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Unfortunately, I was unable to run this display on SPI(1) interface.
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For machine.SPI(2) == VSPI you have to use
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- CLK: Pin(18)
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- MOSI: Pin(23)
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Other SPI pins are not used.
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# ESP32
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import machine
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import st7789
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spi = machine.SPI(2, baudrate=40000000, polarity=1, sck=machine.Pin(18), mosi=machine.Pin(23))
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display = st7789.ST7789(spi, 240, 240, reset=machine.Pin(4, machine.Pin.OUT), dc=machine.Pin(2, machine.Pin.OUT))
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I couldn't run the display on an SPI with baudrate higher than 40MHZ
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Methods
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-------------
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This driver supports only 16bit colors in RGB565 notation.
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- `ST7789.fill(color)`
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Fill the entire display with the specified color.
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- `ST7789.pixel(x, y, color)`
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Set the specified pixel to the given color.
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- `ST7789.line(x0, y0, x1, y1, color)`
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Draws a single line with the provided `color` from (`x0`, `y0`) to
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(`x1`, `y1`).
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- `ST7789.hline(x, y, length, color)`
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Draws a single horizontal line with the provided `color` and `length`
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in pixels. Along with `vline`, this is a fast version with reduced
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number of SPI calls.
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- `ST7789.vline(x, y, length, color)`
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Draws a single horizontal line with the provided `color` and `length`
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in pixels.
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- `ST7789.rect(x, y, width, height, color)`
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Draws a rectangle from (`x`, `y`) with corresponding dimensions
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- `ST7789.fill_rect(x, y, width, height, color)`
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Fill a rectangle starting from (`x`, `y`) coordinates
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- `ST7789.blit_buffer(buffer, x, y, width, height)`
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Copy bytes() or bytearray() content to the screen internal memory.
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Note: every color requires 2 bytes in the array
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Also, the module exposes predefined colors:
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`BLACK`, `BLUE`, `RED`, `GREEN`, `CYAN`, `MAGENTA`, `YELLOW`, and `WHITE`
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Performance
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-----------
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For the comparison I used an excelent library for Arduino
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that can handle this screen.
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https://github.com/ananevilya/Arduino-ST7789-Library/
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Also, I used my slow driver for this screen, written in pure python.
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https://github.com/devbis/st7789py_mpy/
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I used these modules to draw a line from 0,0 to 239,239
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The table represents the time in milliseconds for each case
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| | Arduino-ST7789 | st7789py_mpy | st7789_mpy |
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|---------|----------------|--------------|---------------|
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| ESP8266 | 26 | 450 | 12 |
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| ESP32 | 23 | 450 | 47 |
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As you can see, the ESP32 module draws a line 4 times slower than
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the older ESP8266 module.
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Troubleshooting
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---------------
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#### Overflow of iram1_0_seg
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When building a firmware for esp8266 you can see this failure message from
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the linker:
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LINK build/firmware.elf
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xtensa-lx106-elf-ld: build/firmware.elf section `.text' will not fit in region `iram1_0_seg'
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xtensa-lx106-elf-ld: region `iram1_0_seg' overflowed by 292 bytes
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Makefile:192: recipe for target 'build/firmware.elf' failed
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To fix this issue, you have to put st7789 module to irom0 section.
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Edit `esp8266_common.ld` file in the `ports/esp8266` dir and add a line
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*st7789/*.o(.literal* .text*)
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in the `.irom0.text : ALIGN(4)` section
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