Example code for Oled I2C display gives errors on esp_hal

help
1

Hi everyone, I'm trying to develop on Rust on ESP32 microcontrollers, so far everything's all right and I'm liking the language very much. Yesterday I tried to use a crate to drive an I2C OLED display (128x64 pixels, SH1106 driver), I tried using the embedded_graphics (embedded_graphics - Rust) together with the sh1106 crate specific for my display. I tried using the sample code provide on the crate page with the esp_hal i2c implementation, here is the code:

//! I2C Display example
//!
//! This example prints some text on an SSD1306-based
//! display (via I2C)
//!
//! The following wiring is assumed:
//! - SDA => GPIO4
//! - SCL => GPIO5

//% CHIPS: esp32 esp32c2 esp32c3 esp32c6 esp32h2 esp32s2 esp32s3
//% FEATURES: embedded-hal-02

#![no_std]
#![no_main]

use embedded_graphics::{
    mono_font::{ascii::FONT_6X10, MonoTextStyleBuilder},
    pixelcolor::BinaryColor,
    prelude::*,
    text::{Baseline, Text},
};
use esp_backtrace as _;
use esp_hal::{
    clock::ClockControl, delay::Delay, gpio::Io, i2c::I2C, peripherals::Peripherals, prelude::*,
    system::SystemControl,
};
use esp_println::println;
use sh1106::{prelude::*, Builder};

#[entry]
fn main() -> ! {
    let peripherals = Peripherals::take();
    let system = SystemControl::new(peripherals.SYSTEM);
    let io = Io::new(peripherals.GPIO, peripherals.IO_MUX);
    let mut clocks = ClockControl::boot_defaults(system.clock_control).freeze();
    let mut delay = Delay::new(&clocks);
    let mut i2c = I2C::new(
        peripherals.I2C0,
        io.pins.gpio4,
        io.pins.gpio5,
        100.kHz(),
        &clocks,
        None,
    );
    let mut display: GraphicsMode<_> = Builder::new().connect_i2c(i2c).into();

    display.init().unwrap();
    display.flush().unwrap();

    let text_style = MonoTextStyleBuilder::new()
        .font(&FONT_6X10)
        .text_color(BinaryColor::On)
        .build();

    Text::with_baseline("Hello world!", Point::zero(), text_style, Baseline::Top)
        .draw(&mut display)
        .unwrap();

    Text::with_baseline("Hello Rust!", Point::new(0, 16), text_style, Baseline::Top)
        .draw(&mut display)
        .unwrap();

    display.flush().unwrap();

    loop {
        delay.delay_ms(1000 as u32);
    }
}

Using this code I get the following error in the line where I declare "display":

the trait bound I2C<'_, I2C0, Blocking>: embedded_hal::blocking::i2c::Write is not satisfied
the trait embedded_hal::blocking::i2c::Write is implemented for I2cStubrustcClick for full compiler diagnostic

main.rs(45, 55): required by a bound introduced by this call

builder.rs(119, 14): required by a bound in Builder::connect_i2c

Could you help me figure out what I'm doing wrong? Thank you!

2

OK, I tried to understand more of the problem and if I understood correctly the SH1106 crate uses a call to I2C: hal::blocking::i2c::Write<Error = CommE> that is valid in embedded_hal v0.2, while it is deprecated in v1.0. esp hal uses the 1.0 version of embedded_hal so I get that error. Is there a way to solve this problem? Should I modify the call within the crate to match the new version? Sorry for the inaccurate terms but I'm new to Rust so I'm still getting used to the new environment!

3

For the record I was suggested the solution by someone in another forum, you just have to turn on the "embedded-hal-02" feature flag on esp-hal.

4

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