Hardware Support

[leo60228]

Is the MAix Bit supported by the graphical examples? It seems to have very similar functionality to the Go you're using, but I'm not sure if the pinout is similar enough.

[laanwj]

it looks like the pinout for the LCD pins is slightly different (see the blue pins to the bottom right):

This is for the M1:

This is for the new one:

Assuming they do use the same LCD module, it should be a matter of changing the pin assignments in rust/k210-shared/src/board/def.rs:

/** I/O pins for FPIOA */
#[derive(Copy, Clone)]
pub enum io {
…
    /** LCD chip select (output) */
    LCD_CS = 36,
    /** LCD reset (output) */
    LCD_RST = 37,
    /** LCD Data/Command */
    LCD_DC = 38,
    /** LCD SPI SCLK */
    LCD_WR = 39,
…
}

It has turned out that Maix's documentation diagrams are not always 100% reliable though. I think easiest way to know how to adopt it would be to look at the difference for the Maix-provided C samples for the boards, see what pin numbers they provide to the fpioa set function commands.

[laanwj]

Here's a detailed schematic http://dl.sipeed.com/MAIX/HDK/Maix-Bit/Maix-Bit_1.09/Maix-Bit_1.09%28Schematic%29.pdf, which seems to have the same pin numbers as Maix Go:

LCD_CS 36
LCD_RST 37
LCD_DC 38
LCD_WR 39

It mentions nowhere what exact kind of LCD is used though. Whether this "8bit MCU LCD" is the same ST7789V. As it's the same dimensions and 320×240 resolution I wouldn't be surprised if it was.

Another spec document: http://dl.sipeed.com/MAIX/HDK/Maix-Bit/Specifications/Sipeed%20Maix-BIT%20Specifications_EN%20V2.0.pdf seems it confirms the LCD pins are unswizzled.

[leo60228]

I'm getting mine in about a week. Do you think it would be safe to just try the examples and see if they work?

[laanwj]

I don't think that can do anything really harmful, no. It's similar enough.

Looking at the schematic there are some components missing such as the I2C bus on io_30/io_31. So the acceleratometer/touch screen is not going to work. But only a few of the demos rely on that.

[laanwj]

Please let me know how it goes !