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use core::convert::Infallible;
use core::fmt::Debug;
use core::task::Poll;
use embedded_hal::blocking::i2c::{Operation, Read, Transactional, Write};
use embedded_hal::digital::v2::InputPin;
use crate::Interface;
pub const PN532_I2C_READY: u8 = 0x01;
pub const I2C_ADDRESS: u8 = 0x24;
#[derive(Clone, Debug)]
pub struct I2CInterface<I2C>
where
I2C: Transactional,
I2C: Write<Error = <I2C as Transactional>::Error>,
I2C: Read<Error = <I2C as Transactional>::Error>,
<I2C as Transactional>::Error: Debug,
{
pub i2c: I2C,
}
impl<I2C> Interface for I2CInterface<I2C>
where
I2C: Transactional,
I2C: Write<Error = <I2C as Transactional>::Error>,
I2C: Read<Error = <I2C as Transactional>::Error>,
<I2C as Transactional>::Error: Debug,
{
type Error = <I2C as Transactional>::Error;
fn write(&mut self, frame: &[u8]) -> Result<(), Self::Error> {
self.i2c.write(I2C_ADDRESS, frame)
}
fn wait_ready(&mut self) -> Poll<Result<(), Self::Error>> {
let mut buf = [0];
self.i2c.read(I2C_ADDRESS, &mut buf)?;
if buf[0] == PN532_I2C_READY {
Poll::Ready(Ok(()))
} else {
Poll::Pending
}
}
fn read(&mut self, buf: &mut [u8]) -> Result<(), Self::Error> {
self.i2c.exec(
I2C_ADDRESS,
&mut [Operation::Read(&mut [0]), Operation::Read(buf)],
)
}
}
#[derive(Clone, Debug)]
pub struct I2CInterfaceWithIrq<I2C, IRQ>
where
I2C: Transactional,
I2C: Write<Error = <I2C as Transactional>::Error>,
I2C: Read<Error = <I2C as Transactional>::Error>,
<I2C as Transactional>::Error: Debug,
IRQ: InputPin<Error = Infallible>,
{
pub i2c: I2C,
pub irq: IRQ,
}
impl<I2C, IRQ> Interface for I2CInterfaceWithIrq<I2C, IRQ>
where
I2C: Transactional,
I2C: Write<Error = <I2C as Transactional>::Error>,
I2C: Read<Error = <I2C as Transactional>::Error>,
<I2C as Transactional>::Error: Debug,
IRQ: InputPin<Error = Infallible>,
{
type Error = <I2C as Transactional>::Error;
fn write(&mut self, frame: &[u8]) -> Result<(), Self::Error> {
self.i2c.write(I2C_ADDRESS, frame)
}
fn wait_ready(&mut self) -> Poll<Result<(), Self::Error>> {
if self.irq.is_low().unwrap() {
Poll::Ready(Ok(()))
} else {
Poll::Pending
}
}
fn read(&mut self, buf: &mut [u8]) -> Result<(), Self::Error> {
self.i2c.exec(
I2C_ADDRESS,
&mut [Operation::Read(&mut [0]), Operation::Read(buf)],
)
}
}