ST7789 display is blank

[matheusfinatti]

Seems to be a recurring issue with this driver. I'm sorry if this has been covered before. I'm an amateur when it comes to embedded and it's my first time doing it.

I have a Pi Pico with a Pimoroni Pico Display 2''. From the example in their repo and the datasheet I managed to figure out the display driver and pin layout, which other issues found here seemed to corroborate.

However, my display is black and the code seems to be stuck at the display init() call. I see the backlight turning on, but I don't see the LED on the board turning on. (Moving the led.set_high() to before the display intialization makes the LED turn on)

I've looked at the troubleshooting, tried to change the SPI mode to 0, 1, 2, 3. Nothing changes.

The display works, if I run the example in the manufacturer repo it runs flawleslly

Thanks in advance.

#![no_std]
#![no_main]

use bsp::entry;
use bsp::hal;
use defmt_rtt as _;
use hal::pac;
use panic_halt as _;

use hal::gpio::*;
use hal::Clock;

use rp_pico as bsp;

// Mipidsi drivers
use mipidsi::*;

// Embedded HAL
use embedded_hal::digital::OutputPin;

// Embedded graphics to draw on the display
use embedded_graphics::draw_target::*;
use embedded_graphics::geometry::*;
use embedded_graphics::pixelcolor::*;
use embedded_graphics::primitives::*;
use embedded_graphics::Drawable;

// Embed the 'Hz' function.
use fugit::RateExtU32;

// Display specs
const WIDTH: i32 = 320;
const HEIGHT: i32 = 240;

#[entry]
fn main() -> ! {
    let mut pac = pac::Peripherals::take().unwrap();
    let mut watchdog = hal::Watchdog::new(pac.WATCHDOG);

    let clocks = hal::clocks::init_clocks_and_plls(
        bsp::XOSC_CRYSTAL_FREQ,
        pac.XOSC,
        pac.CLOCKS,
        pac.PLL_SYS,
        pac.PLL_USB,
        &mut pac.RESETS,
        &mut watchdog,
    )
    .ok()
    .unwrap();

    let mut timer = hal::Timer::new(pac.TIMER, &mut pac.RESETS, &clocks);

    let sio = hal::Sio::new(pac.SIO);
    let pins = hal::gpio::Pins::new(
        pac.IO_BANK0,
        pac.PADS_BANK0,
        sio.gpio_bank0,
        &mut pac.RESETS,
    );

    let mut led_pin = pins.gpio25.into_push_pull_output();

    // Configure SPI pins for display
    let spi_mosi: Pin<_, FunctionSpi, PullNone> = pins.gpio19.reconfigure();
    let spi_sclk: Pin<_, FunctionSpi, PullNone> = pins.gpio18.reconfigure();

    // Init SPI
    let spi = hal::Spi::<_, _, _, 8>::new(pac.SPI0, (spi_mosi, spi_sclk));
    let spi = spi.init(
        &mut pac.RESETS,
        clocks.peripheral_clock.freq(),
        62_500_000.Hz(),
        embedded_hal::spi::MODE_0,
    );

    let dc = pins.gpio16.into_push_pull_output();
    let cs = pins.gpio17.into_push_pull_output();

    // SPI interface
    let spi_device = embedded_hal_bus::spi::ExclusiveDevice::new(spi, cs, timer).unwrap();
    let di = display_interface_spi::SPIInterface::new(spi_device, dc);

    // Reset pin must be set to high.
    let mut rst = pins.gpio22.into_push_pull_output();
    rst.set_high().unwrap();

    // Configure the backlight pin, set to high
    let mut bl = pins.gpio20.into_push_pull_output();
    bl.set_high().unwrap();

    // Initialize the display
    let mut display = Builder::new(models::ST7789, di)
        .reset_pin(rst)
        .display_size(WIDTH as u16, HEIGHT as u16)
        .invert_colors(options::ColorInversion::Inverted)
        .orientation(options::Orientation::default())
        .init(&mut timer)
        .unwrap();

    // Code never reaches here
    led_pin.set_high().unwrap();

    // Clear the display initially
    display.clear(Rgb565::GREEN).unwrap();

    // Draw a rectangle on screen
    let style = embedded_graphics::primitives::PrimitiveStyleBuilder::new()
        .fill_color(Rgb565::GREEN)
        .build();

    embedded_graphics::primitives::Rectangle::new(Point::zero(), display.bounding_box().size)
        .into_styled(style)
        .draw(&mut display)
        .unwrap();

    loop {
        // Do nothing
    }
}