embassy/examples/stm32f4/src/bin/dac.rs
Adam Greig c83552eadc
stm32: fix DAC examples
The DAC driver defaults to enabling the channel trigger, but leaves it
at the default value of TIM6 TRGO, then performs a software trigger
after writing the new output value. We could change the trigger
selection to software trigger, but for this example it's simpler to just
disable the trigger.
2023-07-22 12:57:49 +01:00

39 lines
914 B
Rust

#![no_std]
#![no_main]
#![feature(type_alias_impl_trait)]
use defmt::*;
use embassy_executor::Spawner;
use embassy_stm32::dac::{DacCh1, DacChannel, Value};
use embassy_stm32::dma::NoDma;
use {defmt_rtt as _, panic_probe as _};
#[embassy_executor::main]
async fn main(_spawner: Spawner) -> ! {
let p = embassy_stm32::init(Default::default());
info!("Hello World, dude!");
let mut dac = DacCh1::new(p.DAC, NoDma, p.PA4);
unwrap!(dac.set_trigger_enable(false));
loop {
for v in 0..=255 {
unwrap!(dac.set(Value::Bit8(to_sine_wave(v))));
}
}
}
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
}
}