embassy/examples/rp/src/bin/i2c_async.rs

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#![no_std]
#![no_main]
#![feature(type_alias_impl_trait)]
use defmt::*;
use embassy_executor::Spawner;
use embassy_rp::i2c::{self, Config};
use embassy_rp::interrupt;
use embassy_time::{Duration, Timer};
use embedded_hal_async::i2c::I2c;
use {defmt_rtt as _, panic_probe as _};
#[allow(dead_code)]
mod mcp23017 {
pub const ADDR: u8 = 0x20; // default addr
macro_rules! mcpregs {
($($name:ident : $val:expr),* $(,)?) => {
$(
pub const $name: u8 = $val;
)*
pub fn regname(reg: u8) -> &'static str {
match reg {
$(
$val => stringify!($name),
)*
_ => panic!("bad reg"),
}
}
}
}
// These are correct for IOCON.BANK=0
mcpregs! {
IODIRA: 0x00,
IPOLA: 0x02,
GPINTENA: 0x04,
DEFVALA: 0x06,
INTCONA: 0x08,
IOCONA: 0x0A,
GPPUA: 0x0C,
INTFA: 0x0E,
INTCAPA: 0x10,
GPIOA: 0x12,
OLATA: 0x14,
IODIRB: 0x01,
IPOLB: 0x03,
GPINTENB: 0x05,
DEFVALB: 0x07,
INTCONB: 0x09,
IOCONB: 0x0B,
GPPUB: 0x0D,
INTFB: 0x0F,
INTCAPB: 0x11,
GPIOB: 0x13,
OLATB: 0x15,
}
}
#[embassy_executor::main]
async fn main(_spawner: Spawner) {
let p = embassy_rp::init(Default::default());
let sda = p.PIN_14;
let scl = p.PIN_15;
let irq = interrupt::take!(I2C1_IRQ);
info!("set up i2c ");
let mut i2c = i2c::I2c::new_async(p.I2C1, scl, sda, irq, Config::default());
use mcp23017::*;
info!("init mcp23017 config for IxpandO");
// init - a outputs, b inputs
i2c.write(ADDR, &[IODIRA, 0x00]).await.unwrap();
i2c.write(ADDR, &[IODIRB, 0xff]).await.unwrap();
i2c.write(ADDR, &[GPPUB, 0xff]).await.unwrap(); // pullups
let mut val = 1;
loop {
let mut portb = [0];
i2c.write_read(mcp23017::ADDR, &[GPIOB], &mut portb).await.unwrap();
info!("portb = {:02x}", portb[0]);
i2c.write(mcp23017::ADDR, &[GPIOA, val | portb[0]]).await.unwrap();
val = val.rotate_left(1);
// get a register dump
info!("getting register dump");
let mut regs = [0; 22];
i2c.write_read(ADDR, &[0], &mut regs).await.unwrap();
// always get the regdump but only display it if portb'0 is set
if portb[0] & 1 != 0 {
for (idx, reg) in regs.into_iter().enumerate() {
info!("{} => {:02x}", regname(idx as u8), reg);
}
}
Timer::after(Duration::from_millis(100)).await;
}
}