embassy/examples/stm32l4/src/bin/dac.rs
2021-07-24 13:57:11 +02:00

57 lines
1.3 KiB
Rust

#![no_std]
#![no_main]
#![allow(incomplete_features)]
#![feature(trait_alias)]
#![feature(min_type_alias_impl_trait)]
#![feature(impl_trait_in_bindings)]
#![feature(type_alias_impl_trait)]
#[path = "../example_common.rs"]
mod example_common;
use defmt::panic;
use embassy::executor::Spawner;
use embassy_stm32::dac::{Channel, Dac, Value};
use embassy_stm32::gpio::NoPin;
use embassy_stm32::{pac, Peripherals};
use example_common::*;
#[embassy::main]
async fn main(_spawner: Spawner, p: Peripherals) {
info!("Hello World!");
unsafe {
pac::DBGMCU.cr().modify(|w| {
w.set_dbg_sleep(true);
w.set_dbg_standby(true);
w.set_dbg_stop(true);
});
pac::RCC.apb1enr1().modify(|w| {
w.set_dac1en(true);
});
}
let mut dac = Dac::new(p.DAC1, p.PA4, NoPin);
loop {
for v in 0..=255 {
unwrap!(dac.set(Channel::Ch1, Value::Bit8(to_sine_wave(v))));
unwrap!(dac.trigger(Channel::Ch1));
}
}
}
use micromath::F32Ext;
fn to_sine_wave(v: u8) -> u8 {
if v >= 128 {
// top half
let r = 3.14 * ((v - 128) as f32 / 128.0);
(r.sin() * 128.0 + 127.0) as u8
} else {
// bottom half
let r = 3.14 + 3.14 * (v as f32 / 128.0);
(r.sin() * 128.0 + 127.0) as u8
}
}