I2C address is zero for write and write_read on WB55

[alexheslop]

Hi,

Thanks for all the hard work on this HAL, it's been excellent using it so far. I've run into an issue trying to use the I2C on a WB55 Nucleo Board, which I wondered whether you may be able to assist with.

I am seeing an address of 0x00 being no matter what the value I put into the i2c.write or i2c.write_read functions.

Here is my code:

`#![no_std]
#![no_main] // Don't use the Rust standard library, don't use the Rust entry point

use cortex_m::delay;
use hal::{
clocks::Clocks,
gpio::{Pin, PinMode, Port},
i2c::{I2c, I2cConfig},
pac::{self, interrupt, CorePeripherals},
};

use panic_halt as _;
use rtt_target::{rprintln, rtt_init_print};

#[entry]
fn main() -> ! {
rtt_init_print!();

let cp: CorePeripherals = cortex_m::Peripherals::take().unwrap();
let dp: pac::Peripherals = pac::Peripherals::take().unwrap();

let clock_cfg: Clocks = Clocks::default();
clock_cfg.setup().unwrap();

let mut delay = delay::Delay::new(cp.SYST, clock_cfg.systick());

let mut scl = Pin::new(Port::B, 8, PinMode::Alt(4));
scl.output_type(hal::gpio::OutputType::OpenDrain);
scl.output_speed(hal::gpio::OutputSpeed::VeryHigh);
scl.pull(hal::gpio::Pull::Floating);

let mut sda = Pin::new(Port::B, 9, PinMode::Alt(4));
sda.output_type(hal::gpio::OutputType::OpenDrain);
sda.output_speed(hal::gpio::OutputSpeed::VeryHigh);
sda.pull(hal::gpio::Pull::Floating);

let i2c_config = I2cConfig {
    speed: hal::i2c::I2cSpeed::Fast400K,
    mode: hal::i2c::I2cMode::Master,
    address_bits: hal::i2c::AddressBits::B7,
    nostretch: false,
    smbus: false,
    noise_filter: hal::i2c::NoiseFilter::Analog,
};

let mut i2c: I2c<pac::I2C1> = I2c::new(dp.I2C1, i2c_config, &clock_cfg);
delay.delay_ms(500);

loop {
    if i2c.write(0x19, &[0x0F]).is_ok() {
        rprintln!("Write to address: 0x19");
    } else {
        rprintln!("Write failed");
    }

    delay.delay_ms(500);
}

}
`

and a screenshot from a Picoscope with the serial decoding:

It's my first time using this HAL so it's certainly feasible that it's a user error! Thanks in advance.