Custom Boards

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I added the ability to provide a path to a custom board. There are a few requirememnts for this to work properly. The best bet is to look at the files in the custom_board_and_toml_examples/MY_CUSTOM_BOARD folder to see what files are needed and to also get an idea of the kind of information that is in the files.

NOTE: There are only 2 options that get used when supplying a custom board. The first one is the build target and the second is the --custom-board-path command. ALL others are ignored. The reason they are ignored is because you have the ability to set things in the files for the custom board.

The path needs to point to the folder that holds the board specification files. Here is a list of required files.

• board.json: This file outlines what the board is. At a minimum the file needs to contain the following. { "mcu": "{MCU}" } where {MCU} is one of the follwing:

  • esp32
  • esp32s2
  • esp32s3
  • esp32c3
  • esp32c6

• sdkconfig.board: This file contains all of the ESP-IDF specific config settings. If you don't know what needs to be set in here then please ask me for assistance.

• mpconfigboard.h: MicroPython config settings. If you don't know what needs to be set in here then please ask me for assistance.

• mpconfigboard.cmake: Build script. At a minimum the following should be in the build script. {MCU} is replaced with one of the options from the list of MCU's above. {BOARD_CONATINING_FOLDER} if the name of the folder these files are located in.

set(IDF_TARGET {MCU})

set(SDKCONFIG_DEFAULTS
    boards/sdkconfig.base
    ${SDKCONFIG_IDF_VERSION_SPECIFIC}
    boards/{BOARD_CONATINING_FOLDER}/sdkconfig.board
)

• partition.csv: This file dictates what the partitions are supposed to be on the ESP32. As for assistance If you do not know how to create one of these.

NOTE: The .toml file in the custom board example is NOT a requirement. I do strongly suggest using it since it will tie everything together. You can specify all of the display and indev bits and pieces. see TOML Example for further information.

TOML Example

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Here is an example of what you would put inside of the .toml file. I will go over each section below.

[MCU.esp32]
BOARD = "ESP32_GENERIC_S3"
BOARD_VARIANT = "SPIRAM_OCT"
octal_flash = true
flash_size = 16
enable_jtag_repl = 'n'
enable_cdc_repl = 'n'
enable_uart_repl = 'y'
uart_repl_bitrate = 115200

[I80Bus.display_bus]
data0 = 9
data1 = 46
data2 = 3
data3 = 8
data4 = 18
data5 = 17
data6 = 16
data7 = 15
dc = 0
wr = 47
cs = -1
freq = 20000000

[I2C.Bus.i2c_bus]
host = 0
scl = 5
sda = 6
freq = 100000

[I2C.Device.indev_device]
bus = "i2c_bus"
dev_id = "ft6x36.I2C_ADDR"
reg_bits = "ft6x36.BITS"

[ST7796.display]
data_bus = "display_bus"
display_width = 320
display_height = 480
backlight_pin = 45
color_byte_order = "st7789.BYTE_ORDER_BGR"
color_space = "lv.COLOR_FORMAT.RGB565"
rgb565_byte_swap = true

[ST7796.display.init]
params = []

[FT6x36.indev]
device = "indev_device"

[display.set_color_inversion]
params = [true]

[display.set_rotation]
params = ["lv.DISPLAY_ROTATION._90"]

[display.set_backlight]
params = [100]

[task_handler.TaskHandler]
params=[]

• [MCU.{target}]: {target} is the build target you want to use. In the example above we are using esp32 The parameters that immediatly follow are almost the same as what you would use for build commands when entering them from the command line. There are a few rules for how those commands get enetered.

  • options that star with -- need to have the -- removed and all -'s in the name need to be change to _.

  • options are cas esensitive

  • options that take a string value need to be wrapped in double quotes ("value")

  • options that do not take any value MUST have the value set to true

  • options like DISPLAY and INDEV which are able to be repeated cannot be repeated (yet). That means you can onmly supply a single display or indev. You only need to supply the DISPLAY and INDEV if you are not wanting to automatically build the startup script.

    [MCU.esp32] BOARD = "ESP32_GENERIC_S3" BOARD_VARIANT = "SPIRAM_OCT" octal_flash = true flash_size = 16 enable_jtag_repl = 'n' enable_cdc_repl = 'n' enable_uart_repl = 'y' uart_repl_bitrate = 115200

• [{display bus}.{variable name}]: [I80Bus.display_bus], That heading section gets turnmed into display_bus = lcd_bus.I80Bus(...). The variable name you will use when passing the display bus instance to the display driver. I will go into that more later on. The list of options below this heading are the parameters that get passed. These options MUST match the names of the parameters for the class being used.

• [I2C.Bus.{variable name}] and [I2C.Device.{variable_name}]